The Nearctic Realm
The Nearctic Realm, as here defined, consists of most of the continental regions of the United States and Canada, along with parts of northern Mexico and certain satellite islands such as Bermuda. It is bordered by the Arctic Realm to the north and by the Caribbean and Neotropical realms to the south. The physical features and the major biogeographic regions of North America are almost a mirror of those of Palearctic Eurasia. In the northern part, below the polar areas, are vast coniferous forests succeeded by deciduous woodlands, grass prairies, deserts, chaparral, and subtropics. Cutting through these from north to south in western North America is an enormous mountain chain that divides midway into two separate ranges. Today, the climate ranges from subarctic in the north, through temperate to subtropical in Florida and Mexico.
When the ancient supercontinent of Pangaea split into two about 180 million years ago, North America remained joined to Eurasia as part of the supercontinent of Laurasia, while South America was part of the supercontinent of Gondwana. North America later split from Eurasia. The latter has, at various times, been joined by land bridges to Asia, Central and South America since then, which allowed for an exchange of plant and animal species between them (known to science as the Great American Interchange). As a consequence, the Nearctic Realm has relatively few endemics but a rich biodiversity. As in Eurasia, vast Pleistocene ice sheets advanced southward from the polar regions, reaching beyond the Great Lakes and thus covering at their maximum more than half of the continent (curiously, parts of Alaska escaped glaciation). Many large animals, including horses, camels, tapirs, mammoths, mastodonts, ground sloths, sabre-tooth cats (Smilodon), the giant short-faced bear (Arctodus simus), and at least two species of American cheetah (Miracinonyx), became extinct in North America at the end of the ice ages. At the same time, evidence of early modern humans appears and marks the beginning of the ongoing Holocene extinction event. Previously, megafaunal extinctions were believed to have been caused by the changing climate, but many scientists now believe that, while climate change contributed to these extinctions, the primary cause was hunting by these newly arrived humans or, in the case of some large predators, indirectly as a result of their prey becoming scarce. The American bison (Bison bison), brown or grizzly bear (Ursus arctos), moose (Alces alces), and elk or wapiti (Cervus canadensis) all entered North America around the same time as the first humans and explanded rapidly, filling ecological niches left empty by the newly extinct North American megafauna.
Species and subspecies
The ‘grizzly bear’, mentioned above, is the name used for various populations of North American brown bear (Ursus arctos), which first arrived on the continent some 50,000 years ago after crossing the Bering Stait land bridge from eastern Asia. Historically found continuously, and in a very wide ecological range, from the arctic coast of Alaska in the north to Mexico in the south and from the eastern edge of the Great Plains westward to the Pacific, it was in particular an inhabitant of the entire extent of the Rocky Mountains. The almost continual human warfare that has been waged against it, however, along with massive habitat destruction, has resulted in the grizzly having long since vanished from most of these areas. Today it survives only in the large wilderness regions of Alaska and north-western Canada, as well as in some national parks and reserves in the northern continental United States, where it lives mostly in the mountains above the timber line. While the precise taxonomy remains confused and disputed, many of the more isolated populations are known to be under serious threat and a few have already become extinct. Two examples of this include the California grizzly bear (U. a. californicus), which lived in the Sierra Nevada and some coastal areas. The last known individual was shot in 1922, although another individual may have been spotted in Sequoia National Park in 1924. The so-called Mexican grizzly bear, which is now generally thought to have been a population of mainland grizzly (U. a. horribilis), historically occurred in Arizona, New Mexico, Texas, and northern Mexico. Owing to human persecution, by the 1930s this range had decreased to just three isolated mountains in central Chihuahua, Mexico where, by 1960, only 30–40 were left. Hunting, trapping, and poisoning continued unabated, unfortunately, and by the beginning of the 1980s none remained. Whether or not it was actually a distinct subspecies, the loss of these magnificent creatures from so large an area is no less tragic.
The grey or timber wolf (Canis lupus) has undergone an enormous reduction in range over the past 150 years due to human persecution and habitat destruction, but still occurs in reasonable numbers in remoter areas. Of the four generally recognized extant subspecies in North America, only one, the Mexican wolf (C. l. baileyi), is currently considered to be threatened. Two others have gone extinct and are dealt with separately in this text.
The cougar, puma, or mountain lion (Puma concolor) remains one of the most widespread mammals in the Western Hemisphere, being found in a variety of habits across the length of the Americas. In the past a great many subspecies were described, although today only six or seven are generally recognized. The North American cougar (P. c. couguar) includes those populations found in the United States, Canada, Mexico, and most of Central America (possibly as far as South America north-west of the Andes). These large cats were intensively hunted following the European colonization. By the end of the nineteenth century they had been largely extirpated in the eastern part of their range, an area extending from the Maritime provinces of Canada to the Great Plains and southward to Georgia and Alabama. Only remnants survived in remote, mainly northern areas as well as in south Florida, where the ‘Florida panther’ (sometimes considered a distinct subspecies) is critically endangered.
The American bison or buffalo (Bison bison) is divided into two subspecies. The tragic yet ultimately hopeful story of the plains bison (B. b. bison) has been told so many times that it is almost unnecessary to give a detailed account of it here. When Europeans first penetrated into the interior of North America this subspecies occurred south of the range of the wood bison (B. b. athabascae) and east of the Rockies to the north-eastern Mexican states of Durango and Nuevo León, east to the Atlantic seaboard from New York to Georgia (and perhaps as far as Florida). Its centre of distribution was the Great Plains, both in lowlands and highlands. Hence, it had an immense range and constituted a tremendous natural resource, converting prairie grass into tons of meat and hides. The enormous herds utilized the prairies without destroying them and made seasonal migrations on a scale rarely seen in terrestrial mammals. Indeed, at the time of the European arrival in North America the bison were the largest aggregation of land animals on that continent, and perhaps in the world. Only the herds of ungulates that once roamed the savannas of Africa could compare with them in numbers. It is generally believed that the native people had hunted bison for centuries before the European settlers streamed westward. In reality it was at a rather late stage that they began to base their economy on these animals. Hunting bison on foot was certainly not productive. Most cultures of the few tribes inhabiting the prairies were based on the cultivation of maize, beans, and squash. However, when horses became available to native people of the prairies during the seventeenth and eighteenth centuries, quite a new culture developed. Tribes from the mountains converged on the prairies, making use of horses, and quickly changed their economy so that it became based on the bison. Because of the horse the Indians could pursue the bison effectively, but their hunting was still without any negative effect on the overall population. At the beginning of the nineteenth century, when Europeans started to push westwards over the plains, the slaughter of bison commenced, but it was not until the construction of the Union Pacific Railroad in the 1860s that the herds began to be annihilated. Professional hunters moved in and millions of animals were killed. Many deplored this wanton destruction, but any measure to stop or regulate the carnage was opposed by politicians, who saw in the destruction a way to get rid of the ‘Indians’. In the 1870s, Idaho attempted to protect the bison as well as other hoofed animals. Another law giving protection to the bison was passed in Congress, but President Ulysses S. Grant never signed it and the massacres continued. Despite this, a herd numbering several million was reported as late as 1871. However, from then on the number dwindled rapidly. Between 1870 and 1875 at least two and a half million bison were killed every year. In 1883 the last important herd, about 10,000 animals, was destroyed. Only small, stray herds remained in remote areas. One group in Colorado was destroyed by taxidermists in 1897. In 1899 a census put the number of plains bison at just 541, and in Canada there were only a few. Most of these were collected onto various private ranches, with the last-known wild population, consisting of less than 30 animals, living in the area that later became Yellowstone National Park. Although it was the official policy of the United States government to minimize or exterminate the species, and most farmers considered it to be a pest or a nuisance, some people were concerned about the demise of this American icon and took steps to protect it. Some did so with the express purpose of ranching or hunting the animals, but others, such as the American Bison Society, endeavoured to save the species and to reintroduce it into a least part of its former range. In 1908 the National Bison Range in Montana was established, and later other reserves were set aside in the United States and Canada. With growing numbers bison were reintroduced to a number of other protected areas, thus saving it from extinction at the very last moment. Since then it has continued to increase steadily to its current total of around 20,000, although it remains entirely conservation-dependant and largely restricted to national parks and reserves.
Merriam’s elk (Cervus canadensis merriami) was a large deer that inhabited the mountains of California, New Mexico, and Arizona. Competition with cattle and reduction by hunting led to its extermination in about 1906. The Roosevelt elk (C. c. roosevelti) is the largest surviving subspecies of elk in North America, historically found over much of the Pacific Northwest, extending to parts of northern California, where at one time it was heavily hunted. The desire to save it from possible extinction was one of the primary reasons behind the establishment of the Mount Olympus National Monument in 1909 by President Theodore Roosevelt (now Olympic National Park). It was introduced to parts of Alaska in 1928 and reintroduced to coastal British Colombia during the 1980s. The Tule elk (C. c. nannodes) is a notably small subspecies endemic to northern and central California, where it historically ranged from the grasslands and marshlands of the Central Valley to the grassy hills of the coast. When the Europeans first arrived an estimated 500,000 roamed these regions, but by 1870 they were thought to have been wiped out by market hunters during the gold rush. However, in 1874–75, a single breeding pair was discovered in the tule marshes of Buena Vista Lake in the southern San Joaquin Valley. These were protected by a local cattle baron named Henry Miller. A sizeable number were built up on Miller’s ranch, but on his death the latter was subdivided and hunting resumed. By 1895 the population had been reduced to 28. In 1933, rancher Walter Dow took a small group of penned elk to his own ranch in the Owens Valley, east of the Sierra Nevada. Although not native habitat for the animals, they nevertheless thrived there. Today there are over 4000 elk scattered among some two dozen reintroduced herds across the state.
The Columbia white-tailed deer (Odocoileus virginianus leucurus) was once distributed in the north-west from the Columbia River in the north to southern Oregon. Hunting and habitat destruction had reduced it to just a few hundred individuals by the mid-twentieth century, but it has since recovered and is no longer considered to be threatened.
The bighorn sheep (Ovis canadensis) is, as a species, widely distributed throughout the mountains of western North America from southern Canada to Mexico. The desert bighorn sheep (O. c. nelsoni) originally occurred throughout the southwestern United States and north-western Mexico. Heavily hunted, it is now restricted to just three states (Sonora, Baja California, and Baja California Sur) and to Tiburon Island in the Gulf of California. It is unclear whether the desert and peninsular forms represent distinct subspecies, but they are at the very least distinct populations of concern.
The pronghorn (Antilocapra americana) is the only survivor of the Antilocapridae, a family of North American antelope whose closest living relatives are the giraffe and okapi. It is also the fastest hoofed animal in the world, able to achieve speeds of up to 96 km per hour. The species formerly occurred in large herds on the American plains, deserts, and tablelands from Alberta in the north to the Pacific slopes in the west and the Mexican plateaus in the south, where they were said to be as numerous as the bison. During the nineteenth century pronghorns were hunted senselessly, and by 1910 only small, scattered groups remained. Like the bison, those of the prairies escaped extinction at the last minute thanks to legal protection. Three subspecies inhabiting desert areas of the south-western United States and Mexico are still considered to be threatened, however. The Baja California pronghorn (A. a. peninsularis) is confined to a small area of the central Baja California Peninsula, Mexico, where the total population is around 200. The Sonoran pronghorn (A. a. sonoriensis) occurs in southwestern Arizona and north-western Mexico (Sonora). The Mexican pronghorn (A. a. mexicana) is found patchily in north-central Mexico (Chihuahua, Coahuila, Durango, Zacatecas, and San Luis Potosí).
The eastern spotted skunk (Spilogale putorius) was historically common over a wide area of North America, where at one time it was heavily trapped for its fur. Three subspecies are recognized. The Appalachian eastern spotted skunk (S. p. putorius) is now confined to higher-elevation habitats within the Appalachians, although formerly it ranged down into the piedmont and coastal plain of Virginia and the Carolinas. The south-eastern spotted skunk (S. putorius ambarvalis) is found in Florida, Georgia, Alabama, and perhaps elsewhere, while the midwestern spotted skunk (S. p. interrupta) ranges from south-central Canada through the central United States and into north-eastern Mexico.
The New England cottontail rabbit (Sylvilagus transitionalis) was formerly widespread in the north-eastern United States and southern Canada, but has undergone a massive decline due to hunting and habitat destruction. It is now confined to a few scattered areas.
The endemic ground squirrel (Urocitellus endemicus) and the brown ground squirrel (U. brunneus) are both confined to small areas of Idaho, where they are threatened by loss of habitat.
Nelson’s antelope squirrel (Ammospermophilus nelsoni) is confined to the central and western San Joaquin Valley of California as well as to adjacent areas of the inner Coast Ranges. It is threatened by loss of habitat.
The California condor (Gymnogyps californianus), a type of vulture, is the largest land and soaring bird in North America. In prehistoric times it was found across the United States as far as Florida, but with the extinction of the Pleistocene megafauna at the end of the last glacial period its range was significantly reduced. Five hundred years ago it still roamed across the south-west and West Coast from the Columbia River to Mexico and Texas. Human persecution and habitat destruction brought a further tremendous decrease in range in numbers during the twentieth century. By the midtwentieth century it had been confined to the coastal mountains of Santa Barbara and Ventura counties in southern California, where it had only limited protection. When it was clear that these populations too were becoming untenable an ambitious conservation plan was put in place by the United States government. As part of this, all remaining wild condors – just 27 birds – were captured by 1987 and for a time the species became extinct in the wild. The survivors were bred at the San Diego Wild Animal Park and the Los Angeles Zoo. Numbers rose through captive breeding and, beginning in 1991, the species was reintroduced back to the wild at three release sites: northern Arizona and southern Utah (including the Grand Canyon area and Zion National Park), the coastal mountains of central and southern California, and northern Baja California. These populations have continued to grow, but the species remains one of the world’s rarest birds. As of 2017 the total population was 463.
The bald eagle (Haliaeetus leucocephalus) is a type of sea eagle that, after suffering a precipitous decline during the midtwentieth century, is once again found in wetland habitats across most of North America. Overuse of the pesticide DDT, which destroyed its eggs, was the primary cause, although direct human persecution in the form of hunting was also a factor. At its lowest point in the 1950s the species was largely restricted to Alaska, the Aleutian Islands, northern and eastern Canada, and Florida.
The North American osprey (Pandion haliaetus carolinensis) is a large fish-eating hawk that, although notably widespread, was at one time seriously threatened by overcollection of its eggs and hunting, and later by the spraying of pesticides. It has since made a remarkable recovery and is no longer considered threatened.
The spotted owl (Strix occidentalis) is divided into a number of subspecies found patchily from south-western Canada and the western and south-western United States to central Mexico. The California spotted owl (S. o. occidentalis) was historically found in central and southern California and on the Baja California Peninsula, but has been extirpated from the latter. The northern spotted owl (S. o. caurina) is found from south-western British Columbia to northern California. The south-western spotted owl (S. o. huachucae) occurs from Utah and Colorado to Arizona, New Mexico, and extreme western Texas. All are threatened by logging and, to a lesser extent, competition with the barred owl (S. varia), human disturbance, and disease.
The plight of the whooping crane (Grus americana) has long been well-known in North America, resulting in one of the most ambitious conservation recovery efforts in history. This magnificent bird formerly bred in the isolated marshes and bogs of north-western Canada south to Alberta, Manitoba, North Dakota, and Iowa, with an additional breeding population on the coast of Louisiana. Its winter quarters were located along the coast of the Gulf of Mexico from Florida to Mexico. It is thought that there were more than 20,000 birds prior to European settlement of these areas, but relentless shooting and disturbances in both the breeding and wintering grounds reduced this total to around 1300–1400 by 1870, and to just a handful by the 1930s. The latter were confined to the southern Mackenzie River region, fortunately within the confines of Wood Buffalo National Park on the border between Alberta and the Northwest Territories. From there they would migrate southward each year to Texas and Louisiana. After 1938 the entire population wintered in the Aransas National Wildlife Refuge in Texas, which had been established especially for them. This provided an opportunity to take a precise census of the birds each wintering season. When the record-keeping began there were just 14. After years of fluctuating, the population reached a high of 38 in 1961. The following year, however, disaster struck – six birds were lost and no young were born. But in the autumn of 1964 the cranes brought 10 young back to Texas, making a total of 42. In 1970 the figure was 57. By this point a small captive-breeding programme was also underway and numbered around two dozen. Since then the efforts have continued unabated. As of 2017 there were four wild populations totalling some 483 birds. This includes the original natural population along with three reintroduced ones in the eastern United States that are not as yet self-sustaining. The latter includes a large flock that migrates between Wisconsin and Louisiana and two smaller, non-migratory flocks in Florida and Louisiana, respectively. The captive population, meanwhile, totals around 150. All told it has been a remarkable recovery from near and almost certain extinction, but is still a precariously small number to ensure the survival of a long-distance migrant.
The red-crowned Amazon (Amazona viridigenalis) is a type of parrot naturally confined to a small area of northeastern Mexico (Tamaulipas, San Luis Potosí and Querétaro), with an additional, possibly feral population in the Rio Grande Valley of southern Texas, where it is threatened by loss of habitat and illegal collection for the international pet trade. The species has been introduced to parts of Florida, California, Puerto Rico, and Oahu in the Hawaiian Islands.
The story of the passenger pigeon (Ectopistes migratorius) is one of the most tragic in the annals of conservation history. Prior to the permanent settlement by humans in North America, the breeding area of this species covered a vast region from the Great Plains in the west to the Atlantic coast, and from Manitoba and Quebec in the north to the Appalachians and northern Mississippi in the south. Much has been written about it. There is no doubt that the seemingly fantastic accounts of flocks darkening the sky or of their weight breaking great branches from trees where they perched are reliable. The well-known ornithologist Alexander Wilson estimated 2,230,272,000 birds in a single flock that he saw in 1832. Audubon witnessed another immense flock passing over him for hours on end, in such a concentration that the sunlight was almost blotted out and the sky in all directions, as far as the eye could see, was filled with flying pigeons. He calculated that there were well over one billion. A. W. Schorger found as many as 136 million pigeons in a concentrated nesting area in Wisconsin as late as 1871. When the European settlers pushed westwards they hunted passenger pigeons mercilessly, but it was not until professional hunters began to earn their livelihood by killing the birds that the species started to decrease. The annual slaughter of tens of millions in the 1860s and 1870s was more than it could endure. By the 1880s it had become evident that the species was doomed if hunting remained unregulated. Nobody seems to have heeded the warning signs, however, and in the 1890s the species faded out in the wild. The precise cause of the extinction is difficult to determine, but widespread clearance of forests, combined with the expansion of the railway and telegraph networks that enabled the efficient location and harvesting of nomadic nesting colonies, were clearly important factors. Others include disease and, in the final years, breakdown of social facilitation. The last fully authenticated wild specimen was shot near Oakfield, Illinois, on 12 March 1901, although it is possible that another was killed near Laurel, Indiana on 3 April 1902. Various sight records were made up to 1907. The very last individual of the species, ‘Martha’, died in the Cincinnati Zoo in 1914. Thus, in less than 50 years, humans had succeeded in wiping out one of the most abundant birds on Earth.
The tricoloured blackbird (Agelaius tricolor) is relatively widespread along the Pacific coast of North America from northern California to the upper Baja California Peninsula in Mexico. It also remains extremely common and indeed forms the largest breeding colonies of any Nearctic land bird, with one such colony in the 1930s estimated to have contained around 300,000 individuals. Nevertheless, the species has undergone massive declines in recent years due to loss of habitat and persistent insecticide use.
The rusty blackbird (Euphagus carolinus) remains widespread, breeding across the boreal zone of North America from New England to Alaska and wintering across the southwestern United States. Nevertheless, the species has been undergoing massive declines since the mid-twentieth century, the reasons for which are poorly understood.
Bendire’s thrasher (Toxostoma bendirei) is a type of passerine bird found over a relatively wide area of the southwestern United States and north-western Mexico. It is declining everywhere due to loss of habitat and, perhaps, drought.
Belding’s yellowthroat (Geothlypis beldingi) is a type of warbler divided into two subspecies. The nominate form (G. b. beldingi) has been drastically affected by loss of habitat and is now confined to a few small marshes on the southernmost part of the Baja California Peninsula. The northern Belding’s yellowthroat (G. b. goldmaii) is found patchily in the wetlands of the central Baja California Peninsula.
The black-capped vireo (Vireo atricapilla) is a small songbird found over a relatively wide area of the southern United States and Mexico. It has undergone rapid population declines in the past due to habitat destruction and degradation.
The North American box turtle (Terrapene carolina) is divided into a number of subspecies found collectively throughout North America from south of the Great Lakes and east of the Rocky Mountains to southern Mexico. The eastern box turtle (T. c. carolina) is found in southern Canada and in northern and eastern United States. The three-toed box turtle (T. c. triunguis) occurs from eastern Texas to southeastern Kansas, southern Missouri and south-central Alabama. Baur’s box turtle (T. c. bauri) is found in southeastern Georgia and peninsular Florida, along with the Keys and barrier islands of the Gulf of Mexico. The Gulf Coast box turtle (T. c. major) is found in southern Mississippi, southern Alabama, and western Florida. All are threatened by habitat destruction, roadkill, and capture for the pet trade.
The blunt-nosed leopard lizard (Gambelia sila) was historically found in the San Joaquin Valley and adjacent foothills of southern California, where it has been seriously threatened by habitat destruction. It is currently confined to a few scattered parcels of undeveloped land.
Slowinski’s corn snake (Pantherophis slowinskii) is a littleknown species confined to eastern Texas, western Louisiana, and possibly southern Arkansas.
The southern hog-nosed snake (Heterodon simus) is a harmless species that inhabits the coastal plain of the southeastern United States from North Carolina south to Lake Okeechobee in Florida and west to Mississippi. The species has disappeared from many areas due to a multitude of factors including loss of habitat, predation of eggs and hatchlings by fire ants, pesticides, road mortality, and general human persecution. It is now very rare or possibly extirpated in the western part of its range in Mississippi and Alabama.
The Houston toad (Anaxyrus houstonensis) historically occurred in a variety of habitat types across the central coastal region of Texas, but is now confined to a few isolated populations. It disappeared from the Houston area itself during the 1960s, following an extended period of drought and rapid urban expansion. The arroyo toad (A. californicus) is confined to the south-western United States (southern California) and north-western Mexico (Baja California). It is threatened by habitat destruction and predation by introduced fishes and bullfrogs.
The Shasta salamander (Hydromantes shastae) is known only from a few localities within a small area of northern California, typically (although not always) near limestone outcrops. It is threatened by habitat destruction and human disturbance. The limestone salamander (H. brunus) is confined to a small area of the western foothills of the Sierra Nevada in central California, where part of its habitat is protected by a special reserve.
The clouded salamander (Aneides ferreus) is found patchily on Vancouver Island (British Columbia), south-western Oregon, and north-western California. It has suffered significant declines due to intensive, short-rotation logging practices, which result in increasing scarcity of coarse woody debris on the forest floor.
The Del Norte salamander (Plethodon elongatus) is confined to rocky areas within redwood or Douglas fir forests in south-western Oregon and north-western California.
Mountains and Highlands
Like a gigantic barrier, the North American Cordillera runs along the western part of the Nearctic Realm from Alaska into Mexico, its highest peak (Denali, formerly known as Mount McKinley) exceeding 6000 m in height. It consists of three main belts: the Pacific Coast Ranges in the west, the Nevadan belt in the middle (including the Sierra Nevada), and the Laramide belt (including the Rocky Mountains) in the east. Apart from this extensive system of mountains and plateaus there is the much more ancient Appalachian Mountains of the eastern United States and Canada, the peaks and valleys of the Great Basin, and various smaller, isolated massifs located mainly in the southestern United States.
The Utah prairie marmot (Cynomys parvidens) is confined to a small, high-elevation area of south-central Utah. Historically much more widespread, pest control measures in the early twentieth century devastated its range and numbers. By the 1960s it had been reduced to just nine ‘prairie dog towns’ containing less than 3000 animals. The species has recovered somewhat with the banning of poison, but remains threatened.
Townsend’s ground squirrel (Urocitellus townsendii) and Nancy’s ground squirrel (U. nancyae) are both confined to small areas of high-desert shrubland in Washington state, where they are threatened by loss of habitat.
The robust cottontail rabbit (Sylvilagus robustus) is found patchily in the mountains of south-eastern New Mexico, western Texas, and northern Mexico (Coahuila).
The New Mexico shrew (Sorex neomexicanus) appears to be confined to Capitan, Manzano, and Sandia mountains in south-central New Mexico.
The Gunnison grouse (Centrocercus minimus) is a chicken-like bird historically found in the highland areas of the west-central United States. Owing to intensive hunting and habitat destruction it is now confined to a few fragmented populations in Colorado and Utah.
The pinyon jay (Gymnorhinus cyanocephalus) is a permanent resident of the foothills and lower mountains slopes of the western and south-western United States and north-western Mexico (Baja California). It is threatened by the destruction of its preferred habitat (pinyon-juniper woodland).
Bicknell’s thrush (Catharus bicknelli) is one of North America’s rarest and most secretive birds, with a breeding range entirely restricted to the north-eastern part of the continent. A habitat specialist, it favours coniferous mountaintops in south-eastern Quebec and the Maritime provinces of Canada, along with parts of New England, from where it migrates south to the Caribbean.
The Wyoming toad (Anaxyrus baxteri) was common in and around the lakes of the high-elevation Laramie Plains in the 1950s, but underwent a major decline in the following decades. It is currently extinct in the wild. There is a nonreproducing population in Mortenson Lake National Wildlife Refuge, which is maintained with captive-reared individuals.
The Sierra Nevada Mountains
The Sierra Nevada Mountains are located in the western United States between the Central Valley of California and the Great Basin. The vast majority lies in central and eastern California, although the Carson Range spur lies primarily in Nevada. The range is home to three major national parks (Yosemite, Sequoia, and Kings Canyon) and a number of smaller protected areas and national monuments.
The Sierra Nevada bighorn sheep (Ovis canadensis sierrae) is now confined to these mountains. While not threatened, it appears to have historically ranged as far west as the California Coastal Ranges. An account of ‘wild sheep’ in the vicinity of the Mission San Antonio near Jolon, California, and the mountains around San Francisco Bay dates to around 1769.
The Yosemite toad (Anaxyrus canorus) is confined to the wet mountain meadows of the Sierra Nevada Mountains in California, where it has undergone a serious decline in recent decades.
The Sierra Nevada yellow-legged frog (Rana sierrae) was historically found throughout the Sierra Nevada Mountains but has undergone severe declines due to introduced predators, disease, and pollution. The species is now extirpated from Nevada, and only a small number of fragmented populations remain in California.
The diabolical slender salamander (Batrachoseps diabolicus) is confined to a small area of north-central Califorina. The Kings River slender salamander (B. regius) is known only from two localities within Kings Canyon National Park in central California. The Kern Canyon slender salamander (B. simatus) is confined to a small area of central California largely within Sequoia National Forest. The Sequoia slender salamander (B. kawia), Kern Plateau slender salamander (B. robustus), and the relictual slender salamander (B. relictus) are each confined to a small area of south-central California. All are threatened by habitat disturbance.
The Piute cutthroat trout (Oncorhynchus clarkii seleniris) is confined to two tiny streams in the eastern Sierra Nevada.
The Pacific Coast Ranges
The Pacific Coast Ranges are a series of mountain ranges stretching along the western coast of North America from Alaska south to northern and central Mexico.
The Pacific giant salamander (Dicamptodon ensatus), along with its close relatives in the Pacific Northwest, are the largest of all salamanders that have a terrestrial stage. This species is found discontinuously in the damp coastal forests of northern California, where it is threatened in some areas by habitat destruction and degradation.
The California tiger salamander (Ambystoma californiense) is found discontinuously in the coast ranges and surrounding foothills of west-central California, where it is rapidly declining.
The Olympic Mountains
The Olympic Mountains are located on the Olympic Peninsula of western Washington state. Its western slopes are among the wettest places in North America. Most of the mountains are protected within the bounds of Olympic National Park and adjoining segments of the Olympic National Forest.
The Olympic torrent salamander (Rhyacotriton olympicus) is confined to cold, high-elevation streams within the Olympic Mountains.
The Cascade Range
The Cascade Range extends from southern British Columbia through Washington and Oregon to northern California. It includes both volcanic and non-volcanic mountains.
The Cascade Mountains wolf (Canis lupus fuscus) was a cinnamon-coloured subspecies confined to the Cascade Range, where it became extinct in 1940. It has recently been replaced by a different subspecies of grey wolf.
The Oregon slender salamander (Batrachoseps wrighti) is confined to the Cascade Mountains in north-central Oregon.
The Cascade torrent salamander (Rhyacotriton cascadae) occurs in cold mountains streams and spring seepages on the western slopes of the Cascades in Washington and Oregon, where it remains fairly common.
The Klamath Mountains
The Klamath Mountains are located in north-western California and south-western Oregon.
The Siskiyou Mountains are the northermost and largest subrange of the Klamath Mountains.
Storm’s salamander (Plethodon stormi) and the Scott Bar salamander (P. asupak) are each confined to a small area of the Siskiyou Mountains.
The California Coast Ranges
The California Coast Ranges run parallel to the Pacific coast in north-central California, and consist of separate Northern Coast and Southern Coast ranges. Both have a predominantly Mediterreanean climate.
The Santa Cruz Mountains
The Santa Cruz Mountains are located in central and northern California, in the Southern Coast Ranges.
The Santa Cruz long-toed salamander (Ambystoma macrodactylum croceum) is known only from the vicinity of a few isolated ponds within the Santa Cruz Mountains.
The Santa Lucia Mountains
The Santa Lucia Mountains are a rugged subrange located in coastal central California, at the southern end of the Southern Coast Ranges.
The San Simeon slender salamander (Batrachoseps incognitus) and the lesser slender salamander (B. minor) are both confined to the Santa Lucia Mountains.
The Transverse Ranges
The Transverse Ranges are a group of mountain ranges with an east–west orientation located in southern California. Most have a Mediterranean climate.
Stebbins’ slender salamander (Batrachoseps stebbinsi) is confined to isolated areas of the Piute and Tehachapi Mountains.
The San Bernardino Mountains
The San Bernardino Mountains are a high and rugged mountain range in southern California. Recreational development of the range began in the early twentieth century, when resorts were built around irrigation reservoirs. Since then, the mountains have been extensively engineered for transportation and water supply purposes, all of which have had a significant impact on habitats.
The white-eared pocket mouse (Perognathus alticola) is divided into two subspecies separated by the San Gabriel Mountains. The San Bernardino white-eared pocket mouse (P. a. alticolus) is known only from the San Bernardino Mountains. Last collected in 1934, it may be extinct.
The San Gabriel Mountains
The San Gabriel Mountains lie between the Los Angeles Basin and the Mojave Desert, and are within the Angeles National Forest.
The San Gabriel slender salamander (Batrachoseps gabrieli) is confined to the San Gabriel Canyon system, typically between 1000 and 1500 m.
The Tehachapi Mountains
The Tehachapi Mountains extend for approximately 65 km in southern California near the city of Los Angeles. They separate the San Joaquin Valley to the north-west with the Mojave Desert to the south-east, and as such serve as an important wildlife corridor.
The Tehachapi white-eared pocket mouse (Perognathus alticola inexpectatus) is confined to the Tehachapi Mountains, where it is threatened by loss of habitat.
The Peninsular Ranges
The Peninsular Ranges are a group of mountain ranges that stretch 1500 km from southern California to the southern tip of the Baja California Peninsula. Elevations range from 150 to 3300 m. The mountains are arid, with the western slopes of the more northerly ones dominated by montane chaparral and, higher up, by coniferous and mixed evergreen forests. The remaining areas are covered by desert and xeric scrub.
The Baja California rock squirrel (Otospermophilus beecheyi atricapillus) is largely confined to areas near water holes within the Gigantas Sierra and Sierra de San Francisco, where it is threatened by hunting and habitat destruction.
The Santa Rosa Mountains
The Santa Rosa Mountains are a short mountain range located in southern California along the western side of the Coachella Valley.
The sandstone night lizard (Xantusia gracilis) is confined to the Truckhaven Rocks area in the Anza-Borrego Desert State Park, on the south-eastern flanks of the Santa Rosa Mountains.
The desert slender salamander (Batrachoseps major aridus) is known only from two localities on the east slope of the Santa Rosa Mountains.
The San Pedro Mártir Mountains
The San Pedro Mártir Mountains (Sierra de San Pedro Mártir in Spanish) are located in north-western Mexico (Baja California).
Mearns’ squirrel (Tamiasciurus mearnsi) is confined to the San Pedro Mártir Mountains.
The Laguna Mountains
The Laguna Mountains (Sierra de la Laguna in Spanish) are located near the southern tip of the Baja California Peninsula (Baja Peninsula Sur).
The peninsular mouse-eared bat (Myotis peninsularis) is confined to the southern part of the Baja California Peninsula, where it has been reported from all elevations but is relatively dependent upon caves for roosting.
The Colorado Plateau
The Colorado Plateau is an area within western Colorado, north-western New Mexico, southern and eastern Utah, and northern Arizona. The majority is drained by the Colorado River and its tributaries, and much of the rest by the Rio Grande. Largely made up of high desert with scattered areas of forest, the Grand Canyon lies within its south-west corner.
The Kaibab squirrel (Sciurus aberti kaibabensis) is a beautiful, tassel-eared form whose range lies entirely within the ponderosa pine forests of the Kaibab Plateau of Arizona. Fortunately, this area is protected within parts of Grand Canyon National Park and the Kaibab National Forest. In 1964 the total population was estimated at around 1000.
The Appalachian Mountains
The Appalachian Mountains are an ancient chain, weathered down by time, located in eastern North America. The plains and hill country to the west, running from Pennsylvania to Alabama, supports a relatively small ecoregion featuring a remarkable convergence of forest habitats from mixed deciduous in the lowlands to spruce-fir, thus supporting a tremendous diversity of species. The Appalachians are home to some 30 endemic species of lungless salamanders that live on the forest floor, concealed in the leaf litter. These include a number of forms found only on a single isolated mountaintop.
Two subspecies of northern flying squirrel (Glaucomys sabrinus) are found in the southern Appalachians, where they suffered significant declines during the twentieth century. The Virginia flying squirrel (G. s. fuscus) has recovered somewhat in recent years, although the Carolina flying squirrel (G. s. coloratus) remains threatened by loss of habitat.
The Appalachian Plateau
The Appalachian Plateau is a series of rugged, dissected plateaus located on the western side of the Appalachian Mountains.
The Pigeon Mountain salamander (Plethodon petraeus) is confined to Pigeon Mountain in north-western Georgia.
The Tennessee cave salamander (Gyrinophilus palleucus) is known from around two dozen cave sites in Tennessee and Alabama.
The Cumberland Plateau is located in east-central Tennessee.
The laurel dace (Chrosomus saylori) is a type of rare freshwater minnow confined to a few small streams on the Cumberland Plateau.
The Ridge-and-Valley Appalachians
The Ridge-and-Valley Appalachians are a belt situated between the Appalachian Plateau and the Blue Ridge Mountains. They are characterized by long, even ridges and continuous valleys.
The Berry Cave salamander (Gyrinophilus gulolineatus) is confined to a few subterranean localities in eastern Tennessee.
The Blue Ridge Mountains
The Blue Ridge Mountains straddle the eastern flank of the Appalachians and stretch from southernmost Georgia to Pennsylvania. Two major national parks – Shenandoah National Park in the northern section and the Great Smoky Mountains National Park in the south – are contained within the region, along with a number of smaller protected areas.
The Janaluska salamander (Eurycea junaluska) is confined to south-western North Carolina and south-eastern Tennessee.
Several species of woodland salamander (Plethodon) are endemic to the Blue Ridge Mountains, where they are threatened by loss of habitat. The Blue Ridge grey-cheeked salamander (P. amplus) is confined to a few locations in North Carolina. The South Mountains grey-cheeked salamander (P. meridianus) is confined to the South Mountains of western North Carolina. The Shenandoah salamander (P. shenandoah) is known only from three isolated mountains (Hawksbill, The Pinnacles, and Stony Man) in Shenandoah National Park, Virginia. The Big Levels salamander (P. sherando) is confined to a small area in the vicinity of Big Levels, Virginia. The red-legged salamander (P. shermani) is known from a few localities in North Carolina and Tennessee. The Peaks of Otter salamander (P. hubrichti) is known from the Blue Ridge Mountains north-east of Roanoke, Virginia. The Cheoah Bald salamander (P. cheoah) is confined to a small area in western North Carolina. Weller’s salamander (P. welleri) is found patchily in western North Carolina.
The dwarf black-bellied salamander (Desmognathus folkertsi) is a semi-aquatic species confined to a small area of northern Georgia.
The Ozark Mountains
The Ozarks are located in northern Arkansas, southern Missouri, north-eastern Oklahoma, and south-eastern Kansas.
The spring grotto salamander (Eurycea nerea) is confined to the southern Ozark Plateau of Missouri and adjacent northern Arkansas.
The bluestripe darter (Percina cymatotaenia) is confined to six streams in the Osage and Gasconade river drainages of the northern Ozarks, south-central Missouri.
The Ozark cavefish (Amblyopsis rosae) is confined to a few caves and wells of the Springfield Plateau, in the Ozark Mountains.
The Ouachita Mountains
The Ouachita Mountains are located in western Arkansas and south-eastern Oklahoma.
The Fourche Mountain salamander (Plethodon fourchensis) is confined to the Fourche and Irons Fork subranges. The Kiamichi salamander (P. kiamichi) is confined to the Round and Kiamichi subranges. The Sequoyah salamander (P. sequoyah) is confined to the Ouachita Mountains. All are threatened by loss of habitat.
The Kiamichi shiner (Notropis ortenburgeri) and the rocky shiner (N. suttkusi) are both confined to upland streams within the Ouachita Mountains.
Miscellaneous Mountains and Highlands
The Santa Catalina Mountains are located in the southwestern United States (southern Arizona).
The Santa Catalina grey squirrel (Sciurus arizonensis catalinae) is confined to the Santa Catalina Mountains, where it is highly threatened by habitat destruction.
The Manzano Mountains are located in the south-western United States (central New Mexico).
The Manzano cottontail rabbit (Sylvilagus cognatus) is confined to high elevation conifer forests in the Manzano Mountains.
The Inyo Mountains are a short mountain range east of the Sierra Nevadas in eastern California. They separate the Owens Valley to the west and the Saline Valley to the east.
The Inyo Mountains salamander (Batrachoseps campi) is known only from scattered localities in the Inyo Mountains, where it lives along small, permanent desert springs and seeps.
The Panamint Range is a short, rugged mountain range in the northern Mojave Desert of east-central California, and forms the western wall of Death Valley. Being a ‘sky island’ habitat, with more precipitation and temperature variation than the desert floor and hills, it is home to a number of endemic species.
The Panamint alligator lizard (Elgaria panamintina) is a rare and secretive species known from comparatively few museum specimens since its discovery in 1958.
The Spring Mountains are located in the south-western United States (southern Nevada).
Palmer’s chipmunk (Neotamias palmeri) is confined to the Spring Mountains.
The Edwards Plateau is located in the south-western United States (west-central Texas). Essentially a limestone uplift with numerous caves, the landscape is mostly savanna scattered with a few trees.
The golden-cheeked warbler (Setophaga chrysoparia) occurs only in a small part of the Edwards Plateau in south-central Texas. The population is small and declining as a result of bush eradication, in spite of the fact that the bird is protected by law.
During the last few centuries North America has witnessed one of the most violent exploitation of forests that has ever been seen. We are still so close to these drastic alterations that we can hardly appreciate their full significance. The rapid decrease of forests and the habitat changes in them have had serious effects not only on the wildlife but also on entire ecosystems. Many species have been wiped out or are on the verge of extinction. Fortunately, an increasing public as well as official governmental consciousness of the value of unspoiled habitats, rich in wildlife, has done much to ameliorate the situation in Canada and the United States during the last few decades.
The ivory-billed woodpecker (Campephilus principalis) is traditionally divided into two subspecies. The nominate form, the northern ivory-billed woodpecker (C. p. principalis), is (or was) one of North America’s most impressive birds. Historically it occurred in low densities throughout the bottomland swamp forests of the south-eastern United States from the Carolinas, Georgia, and Florida west to Texas, and in the Mississippi Valley north as far as Illinois, where it was highly dependent upon dead and dying trees. Loss of habitat and shooting reduced its numbers, and DDT poisoning may also have been implicated in the disappearance. The last confirmed record was from north-eastern Louisiana in 1944, although in 1950 two ivory-bills were reportedly seen in northern Florida, and in 1960, six. In 1967 a trained ornithologist claimed to have seen it in the Big Thicket country of southeastern Texas, estimating the population at between 5 and 10 pairs. In 2004, it was reportedly rediscovered in the Big Woods region of eastern Arkansas. A thorough investigation of the available evidence, which included a number of sound recordings and a short, poor-quality video, were inconclusive, and subsequent searches of the area have revealed nothing more. There were also unconfirmed reports made by researchers along the Choctawhatchee River in Florida between 2005 and 2007, as well as from Louisiana between 2006 and 2008. In addition, in the years between the last confirmed sightings in the 1960s and the purported ones in the 2000s there were more than 20 others that are at least plausible. There are still large areas of undisturbed habitat available, not least of which being the coastal mangrove and inland hammock forests of south Florida, but unless or until hard evidence is obtained this subspecies must now be considered extinct. The other subspecies, the Cuban ivory-billed woodpecker (C. p. bairdii), may yet survive in south-eastern Cuba.
Two subspecies of Carolina parakeet (Conuropsis carolinensis), a small endemic conure, formerly occurred in oldgrowth riverine and swamp forests of the eastern, Midwestern, and plains states of America, making them the northernmost of all parrots. They seem to have shown a strong preference for deep cypress swamps, but this was not enough to save them from being shot indiscriminately and taken captive in large numbers. It is probable that habitat destruction and disease, although to a lesser degree, also played a role in their ultimate extermination. The birds’ range collapsed from east to west with settlement and clearing of the eastern and southern deciduous forests. The nominate form (C. c. carolinensis) was more a bird of the south-eastern coastal areas, ranging from the Carolinas down through Florida and as far west as southern Louisiana. It was rarely reported outside of Florida after the 1860s, and by the turn of the century was largely confined to swamp forests in the central part of the state. The last-known wild specimens, a flock of 13 birds, were seen (and a few killed) at Lake Okeechobee 1904. ‘Incas’, the last captive specimen, died at the Cincinnati Zoo on 21 February 1918, in the same cage as had ‘Martha’, the last passenger pigeon. The place where the aviary once stood now serves as a monument for both, and is listed as a national historic site. It has been claimed that a small number of parrots may have held on near Lake Okeechobee until the late 1920s, but this cannot now be verified. Reports after this from the Okefenokee Swamp of Georgia and the Santee River swamps of South Carolina are dubious. The Louisiana parakeet (C. c. ludovicianus) appears to have lived more inland that the nominate form, being found generally west of the Appalachians from New York to the Rocky Mountains and south as far as Texas. It was already becoming extremely rare by the mid-nineteenth century. The last confirmed sighting in the wild was in 1910, with total extinction occurring around 1912.
Bachman’s warbler (Vermivora bachmanii) was last reported in 1988 and is most likely extinct. It is known to have bred in Missouri, Arkansas, Kentucky, Alabama, and South Carolina, with additional non-breeding records from various other south-eastern U.S. states. The species wintered in Cuba and, occasionally, Florida. Loss of its riverine swampland habitat appears to have been the cause of the decline.
The Pine Barrens tree frog (Dryophytes andersonii) is found sporadically across the coastal plains of the eastern United States, with populations in New Jersey, the Carolinas, and western Florida and adjacent Alabama. It is also known in Georgia from an old record of a single specimen. Although common where found and not currently considered to be seriously threatened, the disjunct nature of its distribution suggests a formerly much more widespread range.
Lowland Boreal Forests
North America’s boreal forests are located just south of the tundra, covering most of inland Canada, Alaska, and parts of the northern continental United States. They are strikingly similar to those of the Eurasian Region, with the same general pattern of interspersed bogs, lakes, and rivers. Much of the biodiversity is also shared, although the forests of the boreal Nearctic Realm are much richer in species.
The dramatic and tragic history of the plains bison (Bison bison bison) is well known and detailed elsewhere, but the near-extinction and recovery of the wood bison (B. b. athabascae) is also of considerable interest. This northern subspecies – the largest terrestrial animal in North America – historically also had a wide range, extending throughout the boreal forests of Alaska, Yukon, western Northwest Territories, north-eastern British Columbia, northern Alberta, and north-western Saskatchewan. When the plains bison had become almost extinct through wanton exploitation, men turned to the wood bison. It could not withstand the tremendous persecution, and the number dwindled rapidly. It was practically extinct south of the Peace River by 1875, and by 1891 only about 300 remained in an area south of Great Slave Lake. In 1903–04 only 24 individuals were observed, and three years later, 33. In 1922 the Canadian government set aside a protected area, the Wood Buffalo National Park, which included the entire habitat of the remaining herd. By 1929 the population had increased to about 1500, but at that time a serious mistake was made in the introduction into the reserve of no less than 6673 plains bison. As might have been expected, the two subspecies interbred freely and the wood bison disappeared as a pure breed. Fortunately, in 1957 another small herd of some 200, genetically pure animals was discovered in the north-western part of Wood Buffalo National Park, where they had been isolated by swamps. By 1965 only about 100 were left, however, and so 18 were transplanted to Fort Providence north of the Mackenzie River in 1963, in order to establish an independent herd. In 1965 another 43 were captured, destined this time for Elk Island National Park in Alberta. All three of these populations have since prospered with careful management, and additional reintroductions have since taken place elsewhere in Alberta as well as in the Northwest Territories, Yukon, British Columbia, and Manitoba. In 2006 an outherd was established in north-eastern Siberia, where the related steppe bison (B. priscus) died out over 6000 years ago, and there are currently plans to establish populations in Alaska. All told, about 7000 wood bison now live in the wild.
The caribou (Rangifer tarandus), previously discussed in this volume, is also found in Nearctic boreal forests. The woodland caribou (R. t. caribou), the largest subspecies, occurs across southern Canada and the north-western United States, where it is nevertheless considered vulnerable. Osborn’s caribou (R. t. osborni) is confined to an area of British Colombia.
Lowland Broadleaf and Mixed Forests
About 40 per cent of the United States mainland was originally covered by virgin deciduous forest. In 1600 they were still intact except for some local tree removal in the north-eastern states and in Virginia. Today, primeval deciduous forests cover no more than a tiny fraction of this, chiefly in the eastern United States and southern Canada.
The red wolf (Canis rufus) is a controversial form, variously considered to be either a species in its own right (with three subspecies), a subspecies of the grey wolf (C. lupus), or merely a grey wolf / coyote hybrid. Historically these animals were found widely throughout the woodlands of the eastern United States from the Atlantic to the Gulf of Mexico, but were nearly driven to extinction by the mid-nineteenth century due to human persecution, habitat destruction, and extensive hybridization with coyotes (C. latrans). By the late 1960s they survived only in small numbers in the coastal prairies and marshes of western Louisiana and eastern Texas. Fourteen of these survivors were taken into captivity in the 1970s to establish a breeding programme, which has been a success. The red wolf was officially declared extinct in the wild in 1980. In 1987 captives were released into the Alligator River National Wildlife Refuge in North Carolina. A second release, since reversed, took place two years later in the Great Smoky Mountains National Park. In all, 63 animals were introduced to the wild between 1987 and 1994. The population rose to as many as 100–120 in 2012, but declined to just 35 by 2018 as a result of widespread shooting by local hunters, who frequently mistake the wolves for coyotes.
In early colonial days the eastern elk (Cervus canadensis canadensis) ranged throughout the vast forests of southern and eastern Canada and the eastern United States as far west as the Mississipi. It was everywhere common, but always much hunted. Gradually it declined and was at last exterminated. In 1851 John James Audubon noted that a few elk could still be found in the Allegheny Mountains, but that they were virtually gone from the remainder of their range. In Pennsylvania the last one was killed in 1877. A few populations held on till much later in the western parts of the range, where human pressure was less severe. It was found in Minnesota north of Lake Superior as late as 1885, and still existed in Wisconsin in 1892, but (reports from northern Ontario as recently as the 1980s notwithstanding) it was almost certainly extinct by the end of the nineteenth century.
The wood turtle (Glyptemys insculpta) is a semi-aquatic species still found over a wide area of the north-eastern United States and parts of southern Canada. It has declined greatly in number due to loss of habitat and overcollection for the international pet trade.
Lowland Coniferous Forests
Areas of temperate coniferous forest once covered much of North America, mainly in the northern areas. Of special note are the Pacific temperate rainforests that lie along the northwestern coast of North America from Prince William Sound in Alaska, through western British Colombia, Washington, Oregon, and northern California. Unique in being rainforests dominated by conifers, this extraordinary habitat is produced by a combination of maritime moist climate, mild temperature, high rainfall, and the huge mass of organic matter accumulated and produced by the forests themselves. Altogether the region contains a quarter of the world’s remaining temperate rainforests, and is rich in animal life. Sadly, they are highly threatened by logging activity.
Kirtland’s warbler (Dendroica kirtlandii) is a small songbird that very nearly went extinct during the mid-twentieth century. While it may have once been much more widespread, by the 1960s its breeding range had been reduced to a small area of central Michigan, from where the 1000 or so birds that made up the total population migrated to the Bahamas and the Turks and Caicos Islands for the winter. The species has extremely specialized habitat requirements for breeding, namely large areas of dense, young jack pine historically created by forest fires. A stand of growing trees satisfies these warblers for only 10–15 years, after which they move to another area where the trees are smaller. Intensive conservation measures including controlled burning and timber harvesting now produce the exact habitat that the birds need, and as a result they have been able to expand their breeding range into parts of southern Ontario and Wisconsin. The species is now considered to be out of immediate danger.
South-eastern Conifer Forests
The south-eastern conifer forests are located in Louisiana, Mississippi, Alabama, Florida, and Georgia. It represents the largest area of coniferous forest east of the Mississippi River.
The so-called Florida panther is now generally thought to be an isolated, remnant population of North American cougar (Puma concolor couguar), although many scientists continue to recognize it as a distinct subspecies in its own right. As late as the end of the nineteenth century cougars were still common throughout the Florida peninsula as well as in adjacent areas of Georgia, Alabama, and Louisiana. However, constant persecution led to a general decrease in numbers and local extermination until it was gone everywhere except in south Florida, where it lives primarily in protected areas such as Everglades National Park, the Florida Panther National Wildlife Refuge, the Picayune Strand State Forest and the Big Cypress National Preserve. In the 1970s the total wild population had declined to around 20, but this has increased to as estimated 230 by 2017.
The gopher tortoise (Gopherus polyphemus) is an important keystone species owing to the fact that hundreds of others use its burrows. Long hunted for food across the south-eastern United States, today the main threat is habitat destruction and capture for the pet trade.
The Louisiana pine snake (Pituophis ruthveni) historically occurred in parts of west-central Louisiana and extreme eastcentral Texas. It has been reduced to a few isolated areas due to loss of habitat and other factors.
The Rim Rock centipede snake (Tantilla oolitica) is confined to southernmost Florida, where it is threatened by habitat destruction.
The dusky gopher frog (Lithobates sevosus) historically occurred from eastern Louisiana and southern Mississippi to the Mobile River delta in Alabama. Owing to fungal disease and other factors it has declined catastrophically, and by the beginning of the present century was known only from Glen’s Pond in Desoto National Forest, Mississippi. It has since been reported from two additional sites in Mississippi, although it is unclear whether these represent stable populations.
Ainsworth’s salamander (Plethodon ainsworthi) is known only from two specimens collected in Jasper County, Mississippi in 1964. It is most likely extinct.
The Red Hills salamander (Phaeognathus hubrichti) is confined to the Red Hills regions of south-central Alabama, where it inhabits forested ravines. It is threatened by habitat destruction.
Two other species of salamander of the genus Ambystoma are endemic to pine flatwoods habitat in the south-eastern coastal plain. The reticulated flatwoods salamander (A. bishopi) is restricted to Eglin Air Force Base in north-western Florida, while the frosted flatwoods salamander (A. cingulatum) occurs in fragmented populations in South Carolina, Georgia, and Florida.
Florida Sand Pine Scrub
Florida sand pine scrub is an arid subtropical forest region found throughout Florida. It occurs on coastal and inland sand ridges, and is characterized by an evergreen plant community dominated by sand pine shrubs and dwarf oaks.
The Florida black wolf (Canis lupus floridanus) was endemic to Florida, where it became extinct in 1934 due to habitat destruction and hunting.
The Florida deermouse (Podomys floridanus) remains fairly widespread but is everywhere under threat by habitat destruction.
The Florida scrub jay (Aphelocoma coerulescens) has declined significantly since the mid-nineteenth century, and most rapidly since 1950. It is now confined to a few fragmented populations.
The Florida sand skink (Plestiodon reynoldsi) is confined to high sandy ridges in central Florida.
California Coastal Sage and Chaparral
Chaparral is a Mediterranean forest and shrubland or heathland region found primarily in the south-western part of the state of California and the northern Baja California Peninsula of Mexico. This type of habitat burns easily, almost exploding into flame, and fires have long played an important role in forming its development.
The Southern California kit fox (Vulpes macrotis macrotis) was extensively hunted for its fur as well as poisoned during campaigns against coyotes. The last known individual was trapped on the San Jacinto plain in 1903.
Stephens’ kangaroo rat (Dipodomys stephensi) is found in the San Jacinto Valley and adjacent areas of southern California, with the largest known population on the Warner Ranch near Lake Henshaw. The Morro Bay kangaroo rat (D. heermanni morroensis) is confined to the south side of Morro Bay, southern California.
Lowland Grasslands, Savannas, and Shrublands
A wide variety of temperate and subtropical grassland types once covered a broad belt of central North America, with outlying regions in north-western, south-western, and southern United States and northern Mexico.
The black-footed ferret (Mustela nigripes) may have once been the rarest mammal in North America, and indeed very nearly went extinct by the late 1980s. This large weasel is entirely dependent upon prairie-dog towns, which provide it both with prey and den sites. Thus, its former range coincided with that of the ‘prairie dogs’ (Cynomys), that is, the grasslands steppes between southern Canada and northern Mexico. Destruction of the prairie dogs as agricultural pests by means of poisoning and the resulting elimination of prairie-dog burrows, as well as of the original grasslands themselves, was the cause of this species’ decline. By 1970 it had already become extremely rare. In 1981 a small, remnant population of <100 was discovered near Meeteetse, in north-western Wyoming, which was unfortunately decimated by disease within a few years. In 1985, 18 of the survivors were captured in order to serve as the nucleus of a captive breeding programme. The operation was entirely successful, as was a subsequent reintroduction effort. As of 2015 the total wild-living (released or wild-born) population in the United States was around 500, with several hundred additional animals living in ex situ facilities. It must be considered one of the all-time great conservation comeback stories. It should be noted that the black-tailed prairie marmot (Cynomys ludovicianus) itself, while greatly affected by twentieth-century eradication efforts, is today still to be found across most of its former range and is not considered to be threatened. This is fortunate, as many other species in addition to the black-footed ferret are dependent upon its presence for their own survival.
The Great Plains
The Great Plains are a broad expanse of flat land located west of the Mississippi and east of the Rocky Mountains, encompassing much of the Canadian provinces of Manitoba, Saskatchewan, and Alberta and the American states of North Dakota, South Dakota, Nebraska, Kansas, and Oklahoma, along with sizeable parts of Montana, Wyoming, Colorado, New Mexico, Texas, Missouri, Iowa, Illinois, Indiana, Wisconsin, and Minnesota. Historically covered in prairie, steppe, and grassland, much of it has been converted by humans.
The Great Plains grey wolf (Canis lupus nubilus) historically ranged throughout the Great Plains, but was ruthlessly persecuted by humans (encouraged by bounty payments). By 1875 sightings had become rare, and by 1887 they were almost gone. Two were recorded in North Dakota in 1915, and the last known individual was shot in 1922. It was declared extinct in 1926.
The swift fox (Vulpes velox) historically occurred on the plains of south-central Canada and in the adjacent United States south as far as Texas and New Mexico. Driven to the verge of extinction during the 1930s by a predator eradication programme aimed at coyotes and grey wolves, it had been entirely extirpated in Canada by the end of the decade. A programme begun in 1983, however, was successful in reestablishing the animals in south-eastern Alberta and south-western Saskatchewan. While still much reduced in the rest of its former range, the species is now considered to be out of danger in the central United States.
The greater prairie chicken (Tympanuchus cupido) was once found in great numbers on the grassy prairies and along the edges of forests in the central and eastern United States. Cultivation of land and intensive shooting greatly reduced these birds. The now-extinct nominate subspecies, known as the heath hen (T. c. cupido), lived in the scrubby heathland barrens of eastern North America and is discussed elsewhere in this volume. Fortunately, there are still two other subspecies of this extremely interesting and beautiful species living in North America. The Great Plains greater prairie chicken (T. c. pinnatus) is now confined to remaining prairie habitats and prairie mixed with croplands in the Midwest, having disappeared from central southern Canada and a number of American states. The largest remaining populations are in Kansas, Nebraska, and South Dakota. The lesser prairie chicken (T. pallidicinctus) is slightly smaller and paler than the greater prairie chicken. It is patchily distributed in west-central and south-western Kansas, southeastern Colorado, the Oklahoma panhandle, south-western Texas, and eastern New Mexico.
Sprague’s pipit (Anthus spragueii) is a type of passerine bird that breeds in the north-central prairies of southern Canada and northern United States, from where it migrates to the south-western United States and northern Mexico in winter. It is declining due to loss of habitat.
Western Gulf Coastal Grasslands
The western Gulf coastal grasslands are a subtropical grasslands region located in the southern United States (Texas and Louisiana) and north-eastern Mexico (Tamaulipas). Attwater’s greater prairie chicken (Tympanuchus cupido attwateri) historically ranged over the prairies of Texas and Louisiana, but is now restricted to a few areas in coastal southeastern Texas. In 1990 the total population was estimated at less than 1000.
Lowland Deserts and Semi-deserts
The Nearctic Realm includes three major hot deserts (the Chihuahuan, Sonoran, and Mojave), all located in the south-western United States and northern Mexico; one large cold desert (the high-elevation Great Basin Desert); and various smaller cold deserts within the western United States and south-western Canada. In all of these deserts lifeless zones are uncommon and may even serve as a refuge for certain species. The vegetation may be relatively abundant, being chiefly composed of creosote bushes and cacti. There are additional non-desert arid regions in the western United States and in north-eastern, central, and northwestern Mexico. The latter are a kind of transitional zone, colonized mostly by sagebrush and other droughtresisting, low-growing shrubs. To these semi-arid areas a few animals have adapted themselves by evolving specialized characteristics.
The San Joaquin kit fox (Vulpes macrotis mutica) was at one time common throughout much of central California, but for the past half-century has been seriously threatened. In 2007 the Deadman Creek Conservation Bank was created specifically to protect this form, but the population continues to decline due to habitat destruction and competition with red foxes and coyotes.
Kangaroo rats (Dipodomys) are a group of small, bipedal rodents from the semi-arid areas of western North America. A number are threatened by loss of habitat and predation by cats. The giant kangaroo rat (D. ingens) is confined to a narrow strip along the south-western border of the San Joaquin Valley and adjacent areas of southern California, where its historically huge colonies have been reduced to a few small subpopulations. The Fresno kangaroo rat (D. nitratoides) is similarly restricted to the San Joaquin Valley. The Texas kangaroo rat (D. elator) is confined to a small area of north-central Texas and, rarely, in adjacent parts of Oklahoma.
Burt’s harvest mouse (Reithrodontomys burti) is known only from a few localities in north-western Mexico (Sonora and Sinaloa).
Morafka’s desert tortoise (Gopherus morafkai) is confined to Arizona east of the Colorado River and to the Mexican states of Sonora and Sinaloa. Agassiz’s desert tortoise (G. agassizii) is found in the south-western United States (western Arizona, south-eastern California, southern Nevada, and south-western Utah) and possibly north-western Mexico. Both are threatened mainly by loss of habitat.
The reticulated collared lizard (Crotaphytus reticulatus) is confined to a small area of southern Texas and northern Mexico (Coahuila, Nuevo León, and Tamaulipas).
The dunes spiny lizard (Sceloporus arenicolus) is confined to the sand dune systems of extreme south-eastern New Mexico and adjacent western Texas.
The Mojave Desert
The hottest desert in North America, the Mojave is located in the south-western United States primarily within southeastern California and southern Nevada. The north-western part is protected within Death Valley National Park.
The Las Vegas dace (Rhinichthys deaconi) was a type of freshwater fish known only from springs and their outflows along Las Vegas Creek, Nevada. It became extinct when its entire habitat was destroyed many decades ago.
The Pahrump poolfish (Empetrichthys latos) historically had three subspecies, each of which occurred in a different spring within the Pahrump Valley of Nevada. The Raycraft Ranch springfish (E. l. concavus) became extinct when its spring was destroyed in the 1950s. The Pahrump Ranch springfish (E. l. pahrump) became extinct when its spring was pumped dry in 1958. The remaining form (E. l. latos) is the last surviving member of its genus. Extirpated from its native habitat at Manse Ranch Spring, which has been dewatered, it was fortunately successfully translocated during the 2000s to three other localities on public lands.
Death Valley is located in the northern Mojave Desert of eastern California. At 85 m below sea level, it is the lowest elevation in North America as well as one of the hottest places on Earth. It is protected within Death Valley National Park, which extends into adjacent southern Nevada.
The Salt Creek pupfish (Cyprinodon salinus) is divided into two subspecies. The nominate subspecies (C. s. salinus) is confined to Salt Creek; two introduced populations at Soda Lake (San Bernardino County) and River Springs (Mono County) did not persist. The Cottonball Marsh pupfish (C. s. milleri) is confined to a single locality in Death Valley National Park. Several subspecies of Mohave pupfish (C. nevadensis) have become extinct or are seriously threatened. The Tecopa pupfish (C. n. calidae) was endemic to the outflows of a pair of hot springs in California. It was declared extinct in 1981. The Saratoga Springs pupfish (C. n. nevadensis) was historically confined to Saratoga Springs in Death Valley National Park. A population was introduced to Lake Tuendae in California, but may not survive. The Amargosa pupfish (C. n. amargosae) was originally endemic to two sections of the lower Amargosa River. In 1940 a population was introduced at River Springs in California. The Shoshone pupfish (C. n. shoshone) is confined to Shoshone Spring near the town of Shoshone, California, and possibly to parts of the Amargosa River in Nevada as well.
The Sonoran Desert
The Sonoran Desert (Desierto de Sonora in Spanish) covers large parts of the south-western United States in south-western Arizona and south-eastern California as well as north-western Mexico (Sonora, Baja California, and Baja California Sur). The masked bobwhite (Colinus virginianus ridgwayi) is a type of ground-dwelling bird found in the shrublands of southern Arizona and north-western Mexico. Grazing and trampling of the grass by cattle destroyed its habitat to such an extent that by the late twentieth century it was confined to a just few localities in Sonora, Mexico, but populations have since recovered.
The Santa Cruz pupfish (Cyprinodon arcuatus) was endemic to springs and marshes within the upper Santa Cruz River drainage in Arizona, and possibly adjacent areas of the Sonoran Desert in Mexico. The species was extirpated in the wild in the 1960s by water irrigation and flow diversion projects. Attempts at maintaining captive stocks failed in 1971, and the species is now believed to be extinct.
The Sonoran chub (Gila ditaenia) inhabits a few intermittent desert streams, being found throughout the stream system when flow is adequate but restricted to permanent rocky and sandy pools during dry periods.
The Colorado Desert
The Colorado Desert is located in south-eastern California. It includes the heavily irrigated Coachella and Imperial Valleys.
The Coachella fringe-toed lizard (Uma inornata) is confined to a few localities within the Coachella Valley, where it is highly threatened by loss of habitat.
The Chihuahuan Desert
Located in the south-western United States and northern Mexico, the Chihuahuan Desert is the second largest in North America. It covers much of west Texas, parts of the middle and lower Rio Grande Valley and the lower Pecos Valley in New Mexico, and a portion of south-eastern Arizona, as well as the central and northern portions of the Mexican Plateau.
The yellow-margined tortoise (Gopherus flavomarginatus), the largest North American tortoise, once ranged as far north as Arizona and Oklahoma. Today it is restricted to a series of disjunct, isolated basins collectively known as the Bolsón de Mapimí in south-eastern Chihuahua, western Coahuila, and northern Durango, Mexico. The species was heavily exploited during the mid-twentieth century and likely on the way to extinction, although sustained conservation efforts since the 1970s have allowed it to recover.
The Durango mud turtle (Kinosternon durangoense) is known only from the lower Río Nazas and the Bolsón de Mapimí in the Chihuahuan Desert of northern Mexico (southern Chihuahua, western Coahuila, and eastern Durango).
The stumptooth minnow (Stypodon signifer) is known only from six specimens collected from natural springs in the Parras Valley, within the Chihuahuan Desert of northern Mexico (Coahuila), in 1880 and 1903. Repeated attempts to locate it during the mid-twentieth century all failed, and further revealed that the springs had all but disappeared due to habitat modification and pollution. The species is believed to have gone extinct around 1930.
The Big Bend gambusia (Gambusia gaigei) is confined to a few localities within Big Bend National Park, south-western Texas. Two populations are believed to have existed originally; one went extinct in the 1950s when the spring it lived in stopped flowing, and the other was extirpated for a time as well. All surviving individuals are descended from three individuals of the latter population, which has since been reintroduced to the wild. The spotfin gambusia (G. krumholzi) is known only from the Rio de Nava, a small stream in northern Mexico (Coahuila). The San Felipe gambusia (G. clarkhubbsi) is known only from San Felipe Creek in southern Texas.
The White Sands pupfish (Cyprinodon tularosa) is confined to two springs and two small streams in south-western New Mexico.
The Guzmán Endorheic Basin
The Guzmán endorheic basin is located in northern Mexico (north-western Chihuahua) and the south-western United States (south-western New Mexico). Notable rivers include the Casas Grandes River (which empties into Lake Guzmán), the Santa Maria River (which empties into Lake Santa Maria), the Carmen River, and the Mimbres River. It is home to several endemic fish species.
The Chihuahua chub (Gila nigrescens) is confined to a few scattered localities within the Guzmán basin, where it is threatened by habitat destruction and degradation. The Bolsón of the Dead (Bolsón de los Muertos in Spanish) is located in northern Mexico (north-western Chihuahua).
The Carbonera pupfish (Cyprinodon fontinalis) and the largemouth shiner (Cyprinella bocagrande) were both historically confined to the springs and associated waters of the Bolsón of the Dead, but by 2012 only survived in a single dying spring. In 2014 some of each were transferred to a nearby refuge as a safeguard.
The Cuatro Ciénegas Endorheic Basin
The Cuatro Ciénegas (‘Four Marshes’) endorheic basin is located in northern Mexico (Coahuila). This globally important wetland area containing hundreds of spring-fed pools is notable for its high rate of vertebrate and invertebrate species endemism, with some restricted to individual pools of only a few square metres in size.
The Coahuila aquatic box turtle (Terrapene coahuila) is confined to the Cuatro Ciénegas basin.
The Cuatro Cienegas slider (Trachemys taylori) is a type of turtle confined to the Cuatro Ciénegas basin.
The black spiny softshell turtle (Apalone spinifera atra) is confined to the Cuatro Ciénegas basin, where it may be extinct.
Minkley’s cichlid (Herichthys minckleyi) is confined to the Cuatro Ciénegas basin.
The Cuatro Ciénegas shiner (Cyprinella xanthicara) is a type of minnow confined to the spring and spring-fed streams, rivers and wetlands of the Cuatro Ciénegas basin. It has been extirpated from the Laguna Churince, which dried up in 2009 due to excessive groundwater extraction and surface water diversion.
The Santa Tecia platyfish (Xiphophorus gordoni) is confined to a single hot spring (the Laguna Santa Tecia) within the Cuatro Ciénegas basin. Due to the construction of irrigation canals it is not known whether a viable wild population survives, or if the species has instead extended its range.
The Cuatro Ciénegas killifish (Lucania interioris) is confined to a few localities within the Cuatro Ciénegas basin.
The Cuatro Ciénegas gambusia (Gambusia longispinis) is confined to the Cuatro Ciénegas basin.
The Baja California Desert
The Baja California Desert (Desierto de Baja California in Spanish) is located on the western portion of Mexico’s Baja California Peninsula (Baja California and Baja California Sur). While the climate is dry, its close proximity to the Pacific Ocean provides a moderating influence in terms of temperature and humidity.
The San Quintin kangaroo rat (Dipodomys gravipes) was historically confined to a small coastal area of the northwestern Baja California Peninsula, where its habitat has been completely destroyed by agricultural activities. It had not been recorded since 1986 despite exhaustive surveys and was feared extinct until 2017, when a small population was rediscovered in the Valle Tranquilo Nature Preserve.
Dalquest’s pocket mouse (Chaetodipus dalquesti) is confined to ‘foggy desert’ areas on the southern tip of the Baja California Peninsula (Baja California Sur), where it is seriously threatened by tourism development.
Isolated Caves, Springs, and Pools
Many amphibians and fishes in North America are restricted to localities situated in isolated mountains, pools, wells, and cave systems, a fact which makes them vulnerable to extinction.
The black toad (Anaxyrus exsul) is limited to several springs feeding Deep Springs Lake in Inyo County, California, where its population has been more or less stable since the 1970s.
The West Virginia spring salamander (Gyrinophilus subterraneus) is confined to spring passages within General Davis Cave in south-eastern West Virginia. The cave was purchased by the Nature Conservancy and is closed to the public.
A number of largely or wholly aquatic salamanders of the genus Eurycea are endemic to isolated caves, springs, and wells within the Edwards and Floridian aquifers of the southern United States. The Valdina Farms salamander (E. troglodytes) is confined to a single sinkhole in south-central Texas, where it may have become extinct from flooding. The Salado salamander (E. chisholmensis) is known only from a few springs near Salado in east-central Texas. The Georgia blind salamander (E. wallacei) is known only from a handful of subterranean cave streams and wells in southern Georgia and northern Florida. The Cascade Caverns salamander (E. latitans) is confined to deep limestone springs within Cascade Caverns, south-central Texas. The San Gabriel Springs salamander (E. naufragia) is known from a handful of wet caves and springs in east-central Texas within the San Gabriel River watershed. The Barton Springs salamander (E. sosorum) is confined to four hydrologically connected spring outlets within Barton Springs near Austin, Texas. The Comal blind salamander (E. tridentifera) is confined to a few caves in south-central Texas. Rathbun’s blind salamander (E. rathbuni) is confined to Ezell’s Cave within the underground Purgatory Creek in south-central Texas. The Austin blind salamander (E. waterlooensis) is known only from three of the four spring outlets at Barton Springs in east-central Texas, although the full extent of its subterranean range remains unknown. The Balcones Escarpment salamander (E. neotenes) is confined to three springs near San Antonio. The Jollyville Plateau salamander (E. tonkawae) is confined to springs of the Jollyville Plateau north-west of Austin, Texas and a few nearby areas. The Blanco River springs salamander (E. pterophila) is known only from a few springs and caves within the Blanco River watershed of south-central Texas. The Blanco blind salamander (E. robusta) is known only from four specimens observed in south-central Texas in 1951. Its habitat may be largely inaccessible to surveys.
The largescale pupfish (Cyprinodon macrolepis) is confined to a small spring known as El Ojo de Hacienda Delores and its outlet canal in north-central Mexico (Chihuahua). The thick-headed pupfish (C. pachycephalus) is confined to hot springs, their outflows, and an impoundment pool within the Conchos River drainage of northern Mexico (Chihuahua).
The Amistad gambusia (Gambusia amistadensis) is a nowextinct species that lived in Goodenough Spring and its adjacent spring run in south-western Texas. The wild population was exterminated by the building of a reservoir in 1968, and two captive populations failed due to hybridization with the related mosquitofish in the late 1980s. The crescent gambusia (G. hurtadoi) is confined to the El Ojo de Hacienda Delores and its outlet canal, a small spring south-west of Jiménez in northern Mexico (Chihuahua). Its primary habitat is used as a recreational swimming and bathing area. The Clear Creek gambusia (G. heterochir) is confined to Wilkinson Springs on the Clear Creek Ranch, central Texas.
The Railroad Valley springfish (Crenichthys nevadae) is confined to a small number of thermal springs within Railroad Valley in south-central Nevada.
The desert dace (Eremichthys acros) is confined to the thermal springs and outflow streams of Soldier Meadow in north-western Nevada.
The Kendall Warm Springs speckled dace (Rhinichthys osculus thermalis) is confined to a short stretch of warm springs flowing into the Green River in north-western Wyoming.
The Alabama cavefish (Speoplatyrhinus poulsoni) is confined to Key Cave in north-western Alabama, where the total population is thought to be less than 100.
The Mexican blindcat (Prietella phreatophila) is a type of subterranean catfish known only from a few wells and caves in southern Texas and northern Mexico (Coahuila). The phantom blindcat (P. lundbergi) is known only from two caves in north-eastern Mexico (Tamaulipas), where it is threatened mainly by water extraction.
The widemouth blindcat (Satan eurystomus) is confined to five artesian wells in and near San Antonio, Texas.
The toothless blindcat (Trogloglanis pattersoni) is confined to five artesian wells in and near San Antonio, Texas.
The Amargosa River
The Amargosa River is a 300-km-long seasonal river running through the Amargosa Desert along the eastern California – southern Nevada border. Except for flash floods that occur after cloudbursts most of its course is dry on the surface, and the flow is generally underground except for a few short stretches.
The Amargosa vole (Microtus californicus scirpensis) is endemic to a small stretch of the Amargosa River and its associated tributaries and marshes. Long thought to be extinct, it was rediscovered in 1979 but remains extremely rare and threatened by habitat destruction.
The Amargosa toad (Anaxyrus nelsoni) occurs in a few desert springs in western Nevada, where it is threatened by human activities and introduced species.
The Ash Meadows Complex
The Ash Meadows Complex is the underground portion of the Amargosa River, and consists of an area of desert uplands and spring-fed oases. It was designated a National Wildife Refuge in 1984.
The Devil’s Hole pupfish (Cyprinodon diabolis) is the world’s most isolated vertebrate, historically restricted to a single, deep, spring-fed limestone pool at the bottom of Devil’s Hole within Death Valley National Park, southern Nevada (although two artificial populations have been established for larval rearing). Incredibly specialized, it requires warm water and heavy algae growths, requirements that are met only above one ledge about a metre beneath the water. The slightest habitat change may well doom the species, whose numbers have declined alarmingly in recent years. Two subspecies of Mohave pupfish (C. nevadensis), previously discussed, are entirely confined to the Ash Meadows Complex. The Warm Springs pupfish (C. n. pectoralis) is confined to six springs near Devil’s Hole. The Ash Meadows pupfish (C. n. mionectes) is confined to the Ash Meadows National Wildlife Refuge.
The Ash Meadows poolfish (Empetrichthys merriami) was confined to the deeper pools of five separate springs in western Nevada. It was last collected in 1957, and appears to have gone extinct mainly due to habitat alteration.
The Hediondilla Endorheic Basin
The Hediondilla endorheic basin is located in north-eastern Mexico (south-western Nuevo León), near the foot of Cerro Potosi.
The Catarina pupfish (Megupsilon aporus) was first described in 1972 from a single isolated, spring-fed pool in the Hediondilla Basin. In an attempt to save the rapidly declining species some were brought into captivity in the late 1980s and early 1990s, but proved difficult to maintain. It became extinct in the wild in 1994 when the spring dried up, and the captive population also gradually perished. The last specimen died in 2014.
The Potosi pupfish (Cyprinodon alvarezi) was confined to the same pool, where it also became extinct in the wild in 1994. Fortunately, it survives in captivity.
Lakes, Rivers, and Marshes
As a result of its geological past and great glaciers, North America is very rich in lakes and marshes. In their retreat northwards the glaciations left thousands of wetland areas.
The North American beaver (Castor canadensis), like the previously discussed Eurasian beaver, had been brought to the brink of extinction during the nineteenth century due to hunting for its pelt, but has since made a complete recovery.
The Glacier Bay water shrew (Sorex alaskanus) is confined to a small area of southern coastal Alaska.
The trumpeter swan (Cygnus buccinator) is the largest living waterfowl and the heaviest bird in the Nearctic Realm. At the arrival of the Europeans it ranged from Alaska to Mexico, but was thereafter severely depleted by hunting for its meat and feathers. By 1933 fewer than 70 wild individuals were known to exist, all from remote hot springs in or near Yellowstone National Park, and the species seemed doomed to extinction. Careful reintroductions, however, at first to a special refuge in Montana, gradually restored the birds to many areas of Montana, Idaho, and Wyoming. Meanwhile, an aerial survey in the 1950s unexpectedly discovered a population of several thousand in the Copper River region of Alaska. By 2010 the total number exceeded 46,000 throughout north-western and central North America, and the species was no longer considered threatened.
The Nearctic horned grebe (Podiceps auratus cornutus) breeds across much of north-western North America, from where it winters in the south-eastern United States and Mexico. It is declining due to the effects of human disturbance, loss of habitat due to deforestation around breeding lakes, and other factors.
The American crocodile (Crocodylus acutus) is widely distributed across Central and north-western South America, the West Indies, and southern Florida. At one time extensively harvested for its hides, it had been reduced to very low numbers by the 1970s but has since made a recovery. Nevertheless, habitat destruction and illegal hunting remain a threat.
The American alligator (Alligator mississippiensis) is a large freshwater crocodilian largely endemic to the south-eastern United States, where it is distributed from Virginia and North Carolina to southern Florida and westward into Texas and (marginally) north-eastern Mexico (Tamaulipas). Historically quite common, in the 1860s Florida alone was thought to have about three million. Unfortunately, hunting for hides, meat, or often simply out of misguided fear during the nineteenth and much of the twentienth centuries significantly impacted the species, and by the early 1970s it was officially listed as endangered. Subsequent conservation efforts have allowed its numbers to increase, and today it is no longer considered threatened. Indeed, alligators are now commercially harvested in some areas.
Temminck’s alligator snapping turtle (Macrochelys temminckii) is one of the largest freshwater turtles in the world, capable of reaching weights of over 100 kg. While still fairly widespread within the central and south-eastern United States it seems to be naturally rare and is threatened in many areas by collection for the pet trade, overharvesting for its meat, and habitat destruction.
Blanding’s turtle (Emydoidea blandingii) has a range that centres on the Great Lakes and extends from the north-central United States eastwards through southern Ontario and the south shore of Lake Erie as far east as northern New York. There are also isolated populations in south-eastern New York, Pennsylvania, New England, and Nova Scotia. In spite of this wide distribution the species is everywhere rare and localized.
The bog turtle (Glyptemys muhlenbergii) occurs in isolated populations from Connecticut to North Carolina. Its decline is due not only to drainage but also to overexploitation by collectors furnishing the pet trade.
The spotted turtle (Clemmys guttata) is a semi-aquatic species that occurs in wetland areas of southern Canada (Ontario) and the eastern United States (eastern Great Lakes region and east of the Appalachian Mountains as far south as Florida). It has been much reduced in population owing to habitat destruction and overcollection for the pet trade.
The Pacific pond turtle (Actinemys marmorata) was historically widespread within the western Nearctic, where it is usually divided into two subspecies. The northern Pacific pond turtle (A. m. marmorata) was found from south-western Canada (British Colombia) to California, but is now extirpated from Canada and only occurs patchily elsewhere. During the nineteenth century it was heavily exploited for use as food, although since that time the primary threat has been loss of habitat. The southern Pacific pond turtle (A. m. pallida) is confined to the American south-west, extending into northwestern Mexico (Baja California).
The Yaqui slider (Trachemys yaquia) is a type of turtle confined to the Mayo, Yaquia, and Sonora river drainages of north-western Mexico (Sonora and possibly Chihuahua states). It is threatened by loss of habitat and collection for use as food.
The giant garter snake (Thamnophis gigas) is a relatively rare semi-aquatic species found patchily in the wetlands of central California. The San Francisco garter snake (T. sirtalis tetrataenia) is confined to a few scattered wetland areas on the San Francisco Peninsula of California. Both are threatened by loss of habitat.
The Florida bog leopard frog (Lithobates okaloosae) is confined to a few localities within a very small area of northwestern Florida. The Chiricahua leopard frog (L. chiricahuensis) is found widely but patchily in wetlands of the southwestern United States (Arizona and New Mexico) and northern and central Mexico, but is everywhere threatened by loss of habitat and chytrid fungus.
Three highly aquatic frogs of the genus Rana are threatened by loss of habitat, competition with introduced bullfrogs, and predatory introduced fish. The southern mountain yellow-legged frog (R. muscosa) is confined to isolated pockets within the San Jacinto, San Bernardino, San Gabriel, and Sierra Nevada mountains of southern Califoria. The Oregon spotted frog (R. pretiosa) is a rare species that historically occurred from south-western British Colombia to northern California, but which has been extirpated from many parts of its former range. Drayton’s red-legged frog (R. draytonii) is found patchily in California and extreme north-western Mexico (Baja California).
The hellbender (Cryptobranchus alleganiensis) is a large, aquatic salamander that inhabits swift-moving mountain streams and rivers in the eastern United States. The Allegheny hellbender (C. a. alleganiensis) is found found from southern New York to Georgia, while the Ozark hellbender (C. a. bishopi) is confined to the Ozarks of northern Arkansas and southern Missouri. Populations are isolated and declining due to habitat degradation and collection for the pet trade.
The black-spotted newt (Notophthalmus meridionalis) historically occurred across the Gulf Coastal Plain of the southwestern United States and north-eastern Mexico, but has nowadays been reduced to a few scattered localities due to habitat destruction and pollution.
The Ouachita streambed salamander (Eurycea subfluvicola) is known only from two streams within a small area of western Arkansas. The Oklahoma salamander (E. tynerensis) lives in small, clear, spring-fed streams within a small area of the south-central United States (south-western Missouri, north-western Arkansas, and north-eastern Oklahoma).
The North American paddlefish (Polyodon spathula) is the only surviving species of an ancient family of large, shark-like freshwater fishes. The species was historically found throughout the Mississippi River and adjacent drainages, its range extending into the Great Lakes. It has now been extirpated from much of its former range due to overfishing, habitat destruction, pollution, and the relentless demand for caviar.
The shortnose sturgeon (Acipenser brevirostrum) is a relatively small species whose earliest remains are from the Late Cretaceous period, more than 70 million years ago. It lives within the larger coastal rivers and bays along the eastern coast of North America from New Brunswick to Florida. Long harvested for its flesh and eggs, it is now mainly threatened by dam construction and pollution. The lake sturgeon (A. fulvescens) occurs widely within the Mississippi River drainage as well as in the Great Lakes and numerous other rivers and lakes throughout North America. Once killed as a nuisance bycatch because they damaged fishing gear, during the late nineteenth century their flesh and eggs became highly prized and the species became commercially targeted at unsustainable levels. This coupled with pollution and dam construction ultimately resulted in the collapse of the fishery, which has never recovered. While the species remains rare it is not presently considered to be threatened.
The shovelnose sturgeon (Scaphirhynchus platorynchus) was historically found throughout the Mississippi and Missouri river drainages, with a disjunct population formerly occurring in the Rio Grande of northern New Mexico as well. Still commercially fished, it has been extirpated from much of its former range owing to dam construction.
The Atlantic cisco (Coregonus huntsmani) is known only from three freshwater lakes within the Petite Rivière drainage of Nova Scotia, in eastern Canada. It formerly occurred in two other rivers where the populations were anadromous, migrating to coastal estuaries to feed. The shortjaw cisco (C. zenithicus) is largely confined to the Great Lakes basin where it is extant but declining in Lake Superior and apparently extirpated from lakes Michigan, Huron, and Erie. The species occurs as well in Great Slave Lake and from lakes Nipigon, Winnipeg, Athabasca, and a few others in central and northern Canada. Hoy’s cisco or bloater (C. hoyi) formerly occurred in Lake Nipigon and in all of the Great Lakes except for Lake Erie. It is now evidently extirpated in Lake Nipigon and was formerly so from Lake Ontario (although now successfully reintroduced), and is declining in lakes Superior and Huron. All three species are threatened by overfishing, loss of habitat, and introduced predatory fishes.
The silver trout (Salvelinus agassizii) was long confined to two glacial lakes in New Hampshire, where it became extinct before 1939 due to overfishing and competition with introduced species. The bull trout (S. confluentus) remains widespread in north-western North America from the Yukon to, at least historically, northern California. It is everywhere threatened by habitat degradation, dam construction, and hybridization with non-native brook trout.
The Sacramento perch (Archoplites interruptus) is a type of sunfish that was historically found throughout much of California, but has been much reduced due to loss of habitat and introduced fish species. A small native population survives in Clear Lake as well as in gravel pit ponds adjacent to Alameda Creek and the Calaveras Reservoir. Fortunately, the species has been successfully introduced and reintroduced into a number of other localities within the western United States.
The blue-barred pygmy sunfish (Elassoma okatie) is known only from a few localities within the Edisto, New, and Savannah river drainages of South Carolina and Georgia.
The Chesapeake darter (Percina bimaculata) was historically known from the lower Susquehanna River of Pennsylvania and Maryland, as well as the middle to lower Potomac River of Maryland, Virginia, and the District of Columbia. It has not been recorded from the Potomac since the 1930s, and is currently confined to the lower Susquehanna and its tributaries along with a few other, smaller Chesapeake Bay drainages. The Roanoke darter (P. rex) is confined to the Roanoke and Chowan river drainages of the eastern United States (Virginia and North Carolina). Both are threatened by habitat destruction and degradation.
The rush darter (Etheostoma phytophilum) is confined to a few creeks and springs in northern Alabama. The fountain darter (E. fonticola) is confined to the upper San Marcos and Comal rivers in central Texas (spring-fed streams deriving from the Edwards Aquifer). The original Comal River population was extirpated during the mid-1950s, but was reintroduced in the early 1970s.
The western sand darter (Ammocrypta clara) occurs widely but patchily in the river systems of the central United States from Lake Michigan to Texas and as far east as West Virginia. It is everywhere threatened by loss of habitat.
The thicktail chub (Gila crassicauda) was formerly abundant and widespread in the lowland lakes, rivers, and marshes of northern California. A victim of habitat destruction and degradation, the last known specimen was collected from Cache Slough, near Rio Vista, in the late 1950s. The Arroyo chub (G. orcuttii) is confined to a few coastal drainages in south-western California, where it is threatened mainly by habitat destruction and degradation.
The tui chub (Siphateles bicolor) is divided into a number of subspecies within the western United States. The Newark Valley tui chub (S. b. newarkensis) is confined to a small area of Nevada. The Mohave tui chub (S. b. mohavensis) was historically found in the Mojave River, but has been extirpated there. Other populations, most of them introduced, survive elsewhere in southern California.
The Parras characodon (Characodon garmani) was endemic to the Parras Valley of north-central Mexico (Coahuila), where it became extinct sometime before 1953 after its habitat was destroyed.
The whiteline topminnow (Fundulus albolineatus) was known only from Spring Creek, Alabama, where it has not been reported since the 1890s. The broadstripe topminnow (F. euryzonus) is confined to the Tangipahoa and upper Amite rivers within the Lake Pontchartrain drainage of south-eastern Louisiana and south-western Mississippi.
The peppered shiner (Notropis perpallidus) is known only from a few localities within the Red and Ouachita river drainages of south-eastern Oklahoma and southern Arkansas. The blackmouth shiner (N. melanostomus) is confined to a few rivers in northern Florida, southern Alabama and south-eastern Mississippi. The Soto la Marina shiner (N. aguirrepequenoi) is confined to the Soto la Marina and San Fernando rivers in north-eastern Mexico (Tamaulipas and Nuevo León). All are threatened by habitat destruction and degradation.
The bluenose shiner (Pteronotropis welaka) is found sporadically within the Gulf Coast drainages of the south-eastern United States (Mississippi, Alabama, Georgia, and Florida).
The yellowfin gambusia (Gambusia alvarezi) is found disjunctly in northern Mexico within the Salado de Nadadores River and the Cuatro Ciénegas basin of Coahuila, and in the Conchos River and Oje de San Gregorio Spring in Chihuahua.
The Owens Valley pupfish (Cyprinodon radiosus) was historically common in the Owens Valley of eastern California, where it occurred in the Owens River as well as in associated sloughs and desert marshes. It is now confined to a few special refuges. The Organ Pipe pupfish (C. eremus) occurs in two small populations on either side of the U.S./Mexico border in Arizona and Sonora. Additional populations are found within the Sonoyta River, a flood tributary of the Gulf of California, in the lagoon of Quitobaquito, and in refugia outside the native range in Arizona.
The delta smelt (Hypomesus transpacificus) is confined to the upper San Francisco estuary of central coastal California, where it inhabits both fresh and brackish water. The species has undergone a massive decline due to a variety of changes within its habitat and is now seriously threatened.
Price's catfish (Ictalurus pricei) was historically found throughout the rivers of south-eastern Arizona and northern Mexico, but has been extirpated from most of its range due to habitat destruction and water extraction. It still survives within the Yaqui, Fuerte, and possibly the Mayo river drainages, and small populations have been introduced into various other areas from hatchery stock. The headwater catfish (I. lupus) was historically widespread and common in the south-western United States and north-western Mexico but has been extirpated from many areas and undergone declines in many others due to habitat destruction, dam construction, and introduced species.
The orangefin madtom (Noturus gilberti) is a type of catfish confined to parts of the upper Roanaoke and upper James rivers of Virginia and North Carolina. The frecklebelly madtom (N. munitus) has a highly disjunct distribution within the south-eastern United States, where it has been extirpated from many river systems and generally declined since the 1950s due to habitat degradation.
The Santa Ana sucker (Catostomus santaanae) is confined to a few localities within the Los Angeles, San Gabriel, Santa Ana, and (possibly) Santa Clara river drainages in southern California. The Modoc sucker (C. microps) was once thought to be extinct, but is now known to survive within a small number of creeks in northern California and southern Oregon. Conservationists have taken steps to stabilize the remaining habitat, such as the installation of livestockexcluding fences along waterways. The summer sucker (C. utawana) is known only from a few localities within the Adirondack Mountains of the north-eastern United States (New York). The Matalote sucker (C. conchos) is known only from a few localities in north-western Mexico. The Klamath largescale sucker (C. snyderi) is found within the Klamath and Lost River–Clear Lake systems of northern California and southern Oregon.
The shortnose sucker (Chasmistes brevirostris) was historically found throughout the upper Klamath and Lost River – Clear Lake systems of northern California and southern Oregon, but is now confined to a few localities (mainly reservoirs). It is threatened by habitat destruction and degradation.
The Lost River sucker (Deltistes luxatus) was historically widespread and common in the mountain rivers and lakes of northern California and southern Oregon. Only two selfsustaining populations remain (Upper Klamath Lake and Clear Lake).
The harelip redhorse (Moxostoma lacerum) was a type of sucker fish believed to have been historically widespread across much of the eastern and south-eastern United States, yet known only from a few specimens collected between 1859 and 1893 within the Ohio, White, and Maumee river draingages. Now certainly extinct, it is thought to have declined owing to deforestation and land cultivation, which resulted in the siltation of its clear stream habitat. The copper redhorse (M. hubbsi) is confined to the St. Lawrence and Richelieu rivers of south-eastern Canada (south-western Quebec). The robust redhorse (M. robustum) was historically found throughout the coastal drainages of the south-eastern United States (North Carolina, South Carolina and Georgia), but is now reduced to only a few scattered localities due to habitat degradation and introduced predatory fish.
The rough sculpin (Cottus asperrimus) is largely confined to spring-fed tributaries of the Pit River in northern California, including the Fall River and its major tributary, the Tule River, as well as other isolated springs and creeks. It is threatened by habitat destruction, pollution, and introduced fish species.
The unarmoured threespine stickleback (Gasterosteus aculeatus williamsoni) is known for certain only from a small area in southern California, although there have been unconfirmed reports from British Columbia and Mexico.
The darktail lamprey (Lethenteron alaskense) is known only from a few river and creek localities in central and southern Alaska, with an additional highly disjunct record from north-western Canada (Northwest Territories).
The Kern brook lamprey (Lampetra hubbsi) is confined to a few rivers within the eastern San Joaquin Valley of California.
The Great Lakes
The Great Lakes are a group of large freshwater lakes located in north-eastern North America, straddling the Canada–United States border. Once greatly polluted, they have made a comeback in recent years. However, many invasive species, such as the zebra mussel and sea lamprey (Petromyzon marinus), have been introduced due to trade in the area, threatening the region’s biodiversity.
Four species of salmon-like cisco (Coregonus) are believed to have gone extinct within the Great Lakes. The deepwater cisco (C. johannae) from lakes Huron and Michigan was last seen in 1952. The longjaw cisco (C. alpenae) was formerly abundant in the Great Lakes and even sold commercially during the early twentieth century. The last specimen was taken in Georgian Bay, Lake Huron in 1975. The blackfin cisco (C. nigripinnis) historically occurred in lakes Huron, Michigan, Ontario, and Superior. The last known specimens were taken from Lake Huron in 1923 and Lake Michigan in 1969. The shortnose cisco (C. reighardi) was historically found in lakes Michigan, Huron, and Ontario. It has not been reported since 1985 and is most likely extinct. A surviving species, the kiyi cisco (C. kiyi), was formerly widespread within the Great Lakes but is now found only in Lake Superior.
The Klamath Lakes
The Klamath Lakes are located in the Cascade Range of southcentral Oregon. They comprise two large, shallow lakes (Upper Klamath Lake and Lower Klamath Lake), the largest remnants of Lake Modoc, a giant pluvial lake that existed in the region until about 10,000 years ago. During the early twentieth century most of the surrounding wetlands and marshes were drained for agricultural purposes.
The Klamath sculpin (Cottus princeps) and the slender sculpin (C. tenuis) are both confined to the Klamath Lakes, where they are threatened by habitat destruction and degradation.
Lake Bonneville was a prehistoric pluvial lake that covered much of the eastern part of the Great Basin region. Most of the territory it covered was in present-day Utah, although parts of the lake extended into present-day Idaho and Nevada. At more than 300 m deep, the lake was nearly as large as Lake Michigan and significantly deeper. With a change in climate the lake began drying up, leaving Great Salt Lake, Utah Lake, Sevier Lake, Rush Lake, and Little Salt Lake as remnants.
The least chub (Iotichthys phlegethontis) was historically widely distributed within the Bonneville Basin. Today only five wild populations remain. Three of these are in Snake Valley (Leland Harris Spring Complex, Gandy Saltmarsh, and Bishop Spring Complex), and the other two in the Sevier River drainage. An additional, functionally extirpated population also survives at Mona Springs in the Utah Lake drainage.
Utah Lake is a shallow, turbid, and slightly salty lake in the Utah Valley. Its only river outlet, the Jordan River, is a tributary of the Great Salt Lake.
The Utah Lake sculpin (Cottus echinatus) was endemic to rocky nearshore areas of Utah Lake, where it was driven extinct by lowering water levels in the 1930s.
The June sucker (Chasmistes liorus) has disappeared from most of Utah Lake, but survives in the adjacent Provo River and in protected areas throughout Utah.
Lake Lahontan is another prehistoric lake that occupied much of north-western Nevada, extending into north-eastern California and southern Oregon. The area of the former lake covers a large portion of the Great Basin bordering the Sacramento River watershed to the west. The only modern remnants existing as true lakes are Pyramid Lake and Walker Lake. Winnemucca Lake has been dry since the 1930s, and Honey Lake periodically desiccates.
The Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) is a rare subspecies confined to a few creeks and lakes in eastern California and western Nevada.
The Railroad Valley stream tui chub (Siphateles bicolor obesa) is confined to streams and springs within the Lake Lahontan basin, while the Railroad Valley lake tui chub (S. b. pectinifer) inhabits lakes. Both are threatened by habitat degradation.
The cui-ui (Chasmistes cujus) is a large sucker fish endemic to Pyramid Lake in western Nevada, from where it seasonally travels up the Truckee River to spawn. Formerly it also occurred in Winnemucca Lake, which dried up in the 1930s due to water diversion.
One of few natural lakes in the south-eastern United States, Lake Waccamaw in south-eastern North Carolina is notably shallow and was likely formed by a meteoric impact. It has a number of endemic species, all of which are threatened by human water quality interference.
The Carolina pygmy sunfish (Elassoma boehlkei) is confined to Lake Waccamaw and its tributaries.
The Waccamaw darter (Etheostoma perlongum) is confined to Lake Waccamaw and its tributaries.
The Waccamaw silverside (Menidia extensa) is confined to Lake Waccamaw and its tributaries.
The Waccamaw killifish (Fundulus waccamensis) is confined to Lake Waccamaw and its tributaries.
The Mississippi River Drainage
The ‘Mighty Mississippi’ drains most of the area between the Rocky Mountains and the Appalachians, with the exception of the areas drained by Hudson Bay (via the Red River) in the north, the Great Lakes, and the Rio Grande. It is 3733 km long, running from Lake Itasca to the Gulf of Mexico. Together with its main tributaries the Tennessee, Cumberland, and Ohio rivers, along with a large number of smaller rivers and streams and the bayous of the south, it arguably encompasses the richest temperate freshwater ecosystems in the world.
The pallid sturgeon (Scaphirhynchus albus) occurs within the lower Mississippi and Missouri river drainages, where it is threatened by dam construction and, in some areas, hybridization with the related shovelnose sturgeon (S. platorynchus).
The greenback cutthroat trout (Oncorhynchus clarki stomias) is confined to the Arkansas and South Platte rivers on the eastern slopes of the Rocky Mountains in Colorado.
The palezone shiner (Notropis albizonatus) is one of the most endangered fish species in the United States. Historically found throughout the Tennessee and Cumberland drainages, it is now confined to two widely disjunct areas of Kentucky and Alabama. It is threatened by habitat destruction and degradation.
The blotchside darter (Percina burtoni) is widely but disjunctly distributed within the Tennessee and perhaps still the Cumberland drainages of Virginia, North Carolina, Alabama, Tennessee, Georgia, and Kentucky. It is threatened by habitat degradation.
The bayou darter (Etheostoma rubrum) is confined to Bayou Pierre and its tributaries in western Mississippi. The Barrens darter (E. forbesi) is confined to a few tributaries of the Barren Fork and lower Collins rivers in Tennessee. The ashy darter (E. cinereum) is widely but patchily distributed within the Tennessee, Cumberland, and Duck river drainages of the eastern United States. All are threatened by habitat destruction and degradation.
The crystal darter (Crystallaria asprella) was historically found throughout the Mississippi River drainage, but is now absent from much of its former range due to habitat destruction and degradation.
The Missouri River
The Missouri River is the longest river in the United States. It rises in the Rocky Mountains of western Montana and flows east and south before entering the Mississippi north of St. Louis, Missouri.
The Osage River watershed includes an area of eastcentral Kansas and a large portion of west-central and central Missouri, where it drains the north-western Ozark Plateau. It has been impounded in two major locations, and most of the river has been converted into a chain of two reservoirs.
The Niangua darter (Etheostoma nianguae) is confined to a few north-flowing tributaries of the Osage River. Rare and localized, as long ago as 1969 its total population was estimated at less than 1000. It is threatened mainly by loss of habitat.
The Ohio River
The Ohio River is the largest tributary by volume of the Mississippi. It originates in Pennsylvania and flows west to Illinois.
The longhead darter (Percina macrocephala) was historically widespread within the Ohio River drainage but has been extirpated from much of its former range due to habitat degradation.
The spotted darter (Etheostoma maculatum) was historically found throughout the Ohio River drainage but has disappeared from much of its former range due to habitat degradation and introduced species.
The diamond darter (Crystallaria cincotta) was historically found within the Cumberland, Elk, Green, and Muskingum rivers, all tributaries of the Ohio River. It underwent a major decline due to river alterations and a reduction in water quality, and as of 2008 was only known to survive in the Elk River in West Virginia. The effects of the 2014 Elk River chemical spill on the species are unknown.
The Tennessee River is located in the south-eastern United States. It is the largest tributary of the Ohio River and hosts an extraordinary number of endemic fish species.
The spring pygmy sunfish (Elassoma alabamae) is confined to the Moss Springs complex in northern Alabama. Originally this species occurred in two other spring systems as well, but these populations have been extirpated.
The spotfin shiner (Cyprinella monacha) is a type of minnow that was at one time widespread within the Tennessee River system, but today survives in just five isolated tributaries.
The slender chub (Erimystax cahni) is discontinuously distributed in the upper Tennessee River drainage in Tennessee and Virginia.
The Barrens topminnow (Fundulus julisia) is now confined to the Elk River and a drainage creek of the Cumberland Plateau in Tennessee where it usually inhabits heavily vegetated springs. It was previously found within the Duck River drainage as well, but has been extirpated there.
The Tennessee dace (Chrosomus tennesseensis) is confined to small mountain streams in north-eastern Tennessee, southwestern Virginia, and extreme north-eastern Georgia. It is threatened by loss of habitat and introduced species.
Several darters of the genus Etheostoma endemic to the Tennessee River drainage are threatened by habitat destruction and degradation. The Citico darter (E. sitikuense) is largely confined to Citico Creek, a tributary of Tellico Lake, itself an impoundment of the Little Tennessee River in eastern Tennessee. This population previously extended further downstream in Citico Creek before it was inundated by the lake, and the species historically occurred within Abrams Creek as well. The duskytail darter (E. percnurum) is confined to Copper Creek of the Clinch River, itself a tributary of the upper Tennessee River drainage in south-western Virginia. The marbled darter (E. marmorpinnum) is a rare species confined to the Little River drainage in Tennesse. A single specimen was also collected in 1947 from the Holston River, although this population was extirpated due to dam construction. The striated darter (E. striatulum) and the egg-mimic darter (E. pseudovulatum) are both confined to a few small tributaries of the Duck River in central Tennessee. The boulder darter (E. wapiti) is found in the Elk River drainage of southern Tennessee and northern Alabama, but appears to have been formerly more widespread. The golden darter (E. denoncourti) is found within the Tennessee River drainage of Virginia and Tennessee. The slackwater darter (E. boschungi) is confined to the Tennessee River drainage of southern Tennessee and northern Alabama. The Tuscumbia darter (E. tuscumbia) is confined to well-vegetated springs along the southern bend of the Tennessee River in northern Alabama and (formerly) south-central Tennessee. The sharphead darter (E. acuticeps) is known only from the Holston and Nolichucky rivers drainages in eastern Tennessee, western Virginia, and western North Carolina.
The snail darter (Percina tanasi) has played an interesting role in conservation history. Historically confined to three small tributaries within the lower Tennessee River, in 1975 it was involved in a much-publicized legal controversy when the planned Tellico Dam was shown to pose an extinction risk to the species by blocking its migratory route. The fight ultimately led to the United States Supreme Court ruling a halt to the dam’s completion. The dam was ultimately completed and the species was extirpated from the Little Tennessee River. In 1978 a recovery plan to save it was launched, which involved transferring the fish to the Hiwassee River in south-eastern Tennessee. The sickle darter (P. williamsi) is confined to a few scattered localities within the upper Tennessee River drainage of Tennessee, Virginia, and (formerly) North Carolina.
Several catfish of the genus Noturus are endemic to the Tennessee River drainage where they are threatened by habitat degradation. The Chucky madtom (N. crypticus) is a very rare species known only from two creeks within the French Broad River system of eastern Tennessee. A single specimen was collected from Dunn Creek in 1940 and the species is likely extirpated from there, while fewer than 20 others have been recorded from a short stretch of Little Chucky Creek. Surveys of neighbouring streams with potentially suitable habitat have revealed nothing, although the range may historically have extended more widely in Tennessee and Alabama. The smoky madtom (N. baileyi) was endemic to Abrams Creek, a tributary of the Little Tennessee River within Great Smoky Mountains National Park in Tennessee. It was extirpated there during the late 1950s and the species was thereafter thought to be extinct until its rediscovery in 1980 within Citico Creek, in Cherokee National Forest. In 1986 a restoration and reintroduction project was begun and the species has now been established once more at Abrams Creek as well as in the Tellico River. The pygmy madtom (N. stanauli), the world’s smallest catfish, is found only within two short, widely separated reaches of the Duck and Clinch rivers in the Tennessee River drainage. The yellowfin madtom (N. flavipinnis) was historically widespread throughout the upper Tennessee River drainage of Tennessee, Virginia, and Georgia, but is now believed to be largely confined to Citico Creek in Tennessee, with a further reintroduced population within Abrams Creek in Virginia. The saddled madtom (N. fasciatus) is confined to the Duck River drainage and and two small tributaries of the lower Tennessee River.
The Cumberland River runs from its source on the Cumberland Plateau in Tennessee to its confluence with the Ohio River in Kentucky.
The blackside dace (Chrosomus cumberlandensis) is confined to small tributaries of the upper Cumberland River near Cumberland Falls.
The bluemask darter (Etheostoma akatulo) occurs within a few small rivers and streams within the middle Cumberland River drainage of Tennessee. The tuxedo darter (E. lemniscatum) is confined to the Big South Fork tributary of the Cumberland River in Tennessee and Kentucky. Susan’s darter (E. susanae) is found in scattered streams within the Cumberland River drainage in eastern Kentucky and adjacent Tennessee. All are threatened by habitat destruction and degradation.
The Kentucky River is located in eastern Kentucky.
The Cumberland Plateau darter (Etheostoma spilotum) is confined to the upper Kentucky River drainage, where it is potentially threatened by pollution from coal mining operations.
The Green River is a tributary of the Ohio River located in south-central Kentucky.
The Shawnee darter (Etheostoma tecumsehi) is confined to upland tributaries of the upper Pond River in the Green River system. These headwaters originate on the Dripping Springs Escarpment of the Mammoth Cave Plateau, and drain a small part of the Shawnee Hills section, one of the smallest known ranges of any darter species.
The Scioto River is located in central and southern Ohio.
The Scioto madtom (Noturus trautmani) was a type of catfish known only from riffles in Big Darby Creek, a tributary of the Scioto River. It has not been collected since 1957, and is most likely extinct.
The Arkansas River
The Arkansas River is a major tributary of the Mississippi and one of the longest rivers in the United States. It originates in the Rocky Mountains of Colorado and flows generally east and south-east through Kansas, Oklahoma, and Arkansas.
The Arkansas River shiner (Notropis girardi) was historically widespread and abundant throughout the western portions of the Arkansas River drainage, but is now almost entirely confined to the Canadian River in Oklahoma, Texas, and New Mexico. It has also been successfully introduced into the Pecos River of New Mexico.
The Arkansas River speckled chub (Macrhybopsis tetranema) historically occurred throughout the Arkansas River drainage but is now confined to a small portion of the river in Kansas, as well as in the Ninnescah and South Canadian rivers.
The Red River
The Red River (sometimes known as the Red River of the South) is located in northern Texas, southern Oklahoma, Arkansas, and Louisiana. It has been greatly modified due to dam construction and impoundments.
The prairie chub (Macrhybopsis australis) is confined to the upper Red River drainage of southern Oklahoma and northern Texas. The species has been extirpated from many areas due to loss of habitat.
The Little River is located in south-western Arkansas and southern Oklahoma.
The leopard darter (Percina pantherina) is confined to the Little River drainage.
The yellowcheek darter (Etheostoma moorei) is confined to the Little River drainage.
The Coosa / Alabama / Mobile River Drainage
The Coosa / Alabama / Mobile river waterway is located in the south-eastern United States (Tennessee, Georgia, and Alabama).
The blue shiner (Cyprinella caerulea) is a type of minnow confined to a few localities within the Cahaba and Coosa rivers, where it is threatened by habitat degradation.
The Cahaba shiner (Notropis cahabae) is confined to the Cahaba and Black Warrior drainages.
The goldline darter (Percina aurolineata) is known from a few scattered localities within the Coosa River drainage of north-western Georgia and the Cahaba River drainage of Alabama. The coal darter (P. brevicauda) is found patchily within the Coosa, Cahaba, and Black Warrior drainages of north-central Alabama. Both are threatened by habitat destruction and degradation.
The Coosa River
The Coosa River is the name for the upper section of the Coosa / Alabama / Mobile River drainage. Its drainage covers parts of much of north-eastern Alabama as well as northwestern Georgia and extreme south-eastern Tennessee.
The bridled darter (Percina kusha) and the amber darter (P. antesella) are both known only from the Conasauga, Coosawattee, and Etowah drainages of north-western Georgia and south-eastern Tennessee, where they are threatened by habitat degradation.
The holiday darter (Etheostoma brevirostrum), trispot darter (E. trisella), and the coldwater darter (E. ditrema) are all found sporadically within the Coosa River drainage of northeastern Alabama, north-western Georgia, and south-eastern Tennessee, where they are threatened by habitat degradation.
The pygmy sculpin (Cottus paulus) is confined to Coldwater Spring and its associated spring run, in the Coosa River system of northern Alabama.
The Etowah River is located in north-western Georgia.
The Cherokee darter (Etheostoma scotti) and the Etowah darter (E. etowahae) are both confined to the Etowah River and a few of its tributaries, where they are threatened by habitat degradation.
The Conasauga River is located in southern Tennessee and north-western Georgia.
The Conasauga darter (Percina jenkinsi) is known only from a small stretch of the Conasauga River and its tributary, the Jacks River. It is seriously threatened by habitat degradation.
The Alabama River
The Alabama River is the name for the central section of the Coosa/Alabama/Mobile River drainage.
The Alabama sturgeon (Scaphirhynchus suttkusi) historically occurred throughout the Alabama River drainage in Alabama and Mississippi, but has been reduced due to overfishing and habitat destruction to the lower Alabama and possibly Cahaba rivers, where it has rarely been seen in recent decades. Plans for a captive-breeding and reintroduction programme are underway.
The Mobile River
The Mobile River is the name for the lower section of the Coosa/Alabama/Mobile River drainage.
The Alabama red-bellied cooter (Pseudemys alabamensis) is a type of turtle that was formerly found throughout the lower Mobile River drainage in Alabama, and perhaps east into the Florida Panhandle. It is now reduced to Mobile Bay and a few tributary streams.
The Black Warrier River is located in west-central Alabama. It arises on the extreme southern edges of the Appalachian highlands and flows some 286 km to the Tombigbee River, of which it is the primary tributary.
The flattened musk turtle (Sternotherus depressus) is an exclusively aquatic species confined to the Black Warrior River drainage.
The Alabama waterdog (Necturus alabamensis) is a rare type of aquatic amphibian confined to a few portions of the upper Black Warrior River drainage.
The Bankhead darter (Percina sipsi) is known only from four streams from the Sipsey Fork of the Black Warrior River. The vermilion darter (Etheostoma chermocki) is confined to the Turkey Creek watershed, a tributary of the Black Warrier River. Its habitat was designated as a nature preserve in 2010. The watercress darter (E. nuchale) is confined to four localities, two within the Watercress Darter National Wildlife Refuge and the other two at Seven Springs in the city of Birmingham. The warrior darter (E. bellator) is confined to a few localities within the Black Warrior drainage.
The San Marcos River
The San Marcos River is located in south-central Texas.
The San Marcos gambusia (Gambusia georgei) was restricted to the San Marcos Spring and upper few kilometres of the San Marcos River. Estimated at less than 1000 individuals in 1969, it was devastated by habitat pollution and alteration as well as by interbreeding with a related introduced species. No genetically pure specimens have been found since 1983.
The San Marcos Springs
The San Marcos springs are the source of the San Marcos River.
The San Marcos Springs salamander (Eurycea nana) is confined to a single pool within the San Marcos Springs.
The Pascagoula River
Located in south-western Mississippi, with tributaries extending into south-eastern Louisiana, the Pascagoula River is formed by the confluence of the Leaf and Chickasawhay rivers. It flows generally southwards through swampy bottomlands before eventually branching out into a number of channels and bayous.
The Pascagoula map turtle (Graptemys gibbonsi) and the yellow-blotched sawback (G. flavimaculata) are both confined to the Pascagoula River drainage, where they underwent a serious decline in the late twentieth century and have yet to recover.
The Pascagoula darter (Percina aurora) is nowadays confined to the Pascagoula River drainage. It formerly occurred in the Pearl River as well, but has since been extirpated due to loss of habitat and pollution.
The Pearl River
The Pearl River is located in south-eastern Louisiana and western Mississippi. It contains large areas of bottomland hardwood swamp and cypress swamp.
The Pearl River map turtle (Graptemys pearlensis) is restricted to the main course and major tributaries of the Pearl and Bogue Chitto rivers,where the population has declined dramatically since the mid-twentieth century. The ringed sawback (G. oculifera) is similarly confined to these two drainages.
The Apalachicola River
Located in the Florida Panhandle, the Apalachicola River is formed by the confluence of the Chattahoochee and Flint rivers.
Barbour’s map turtle (Graptemys barbouri) inhabits the Apalachicola River and nearby systems in Florida, Georgia, and Alabama. It is threatened by overharvesting for food and the pet trade, habitat degradation, predation, and disease.
The Halloween darter (Percina crypta) is found patchily in the Apalachicola, Flint, and Chattahoochee rivers.
The Ouachita River
The Ouachita River runs south and east throught the states of Arkansas and Louisiana before joining the Tensas River to form the Black River.
The Ouachita madtom (Noturus lachneri) is a type of catfish confined to the upper forks of the Saline River (a tributary of the Ouachita River in south-central Arkansas) and one other tributary of the Ouachita River.
The Caddo River
The Caddo River is located in south-central Arkansas. The paleback darter (Etheostoma pallididorsum) is found only in the Caddo River and in Hallmans Creek.
The Caddo madtom (Noturus taylori) is a type of catfish confined to the upper Caddo River.
The Rio Grande
The Rio Grande is a major river of the south-western United States and northern Mexico. It begins in south-central Colorado and flows to the Gulf of Mexico. Many endorheic basins are situated within, or adjacent to, the river’s course.
The Big Bend slider (Trachemys gaigeae) is a type of turtle divided into two subspecies. The nominate form (T. g. gaigeae) is confined to the upper Rio Grande and its tributary, the Conchos River in New Mexico, Texas, and northern Mexico (Chihuahua and Coahuila). The Nazas slider (T. g. hartwegi) is confined to the Nazas River in northern Mexico (Coahuila and Durango). Both are threatened by habitat degradation, collection for the pet trade, and other factors.
Two species of shiner (Notropis) were historically endemic to the Rio Grande drainage. The phantom shiner (N. orca) ranged from the upper Rio Grande of New Mexico to the mouth of the river. Extremely rare by the mid-twentieth century, it was last collected in 1975 and is now considered extinct. The bluntnose shiner (N. simus) is divided into two subspecies. The nominate subspecies (N. s. simus) was last collected in New Mexico in 1964 and is now considered extinct.
The Proserpine shiner (Cyprinella proserpina) is a type of minnow confined to rocky runs and the pools of creeks and small rivers in the Rio Grande drainage.
The Rio Grande darter (Etheostoma grahami) is largely confined to the mainstream and spring-fed tributaries of the Rio Grande drainage.
The Rio Grande silvery minnow (Hybognathus amarus) is confined to the Rio Grande and Pecos rivers.
The Tex-Mex gambusia (Gambusia speciosa) is confined to springs, outflows, marshes, and the margins of small to medium streams within the Rio Grande drainage.
The Rio Grande sucker (Catostomus plebeius) is confined to the Rio Grande drainage.
The Pecos River
The Pecos River originates in the mountains of eastern New Mexico and flows into western Texas, where it empties into the Rio Grande.
The Pecos bluntnose shiner (Notropis simus pecosensis) was historically found throughout the Pecos River drainage, but is now confined to the stretch between Fort Sumner and Artesia.
The Pecos gambusia (Gambusia nobilis) is confined to scattered sinkholes, springs, and their outflow in the Pecos River drainage.
The Leon Springs pupfish (Cyprinodon bovinus) was first discovered in 1851 at Leon Springs near Fort Stockton, Texas. The springs were later impounded, poisoned, stocked with game fish, and drained, and the species was considered extinct by 1938. During the 1960s, however, it was rediscovered at Diamond Y Spring a short distance away, and later in the Diamond Y Draw, a tributary of the Pecos River. The elegant pupfish (C. elegans) was historically found in two disjunct areas of western Texas within the Pecos River drainage. One was Comanche Springs, which dried up during the 1950s resulting in the extirpation of that population. The species is therefore now confined to a small series of spring-fed pools, outflows, and irrigation canals near the town of Balmorhea. The Pecos pupfish (C. pecosensis) was historically found throughout the Pecos River drainage, but populations have become inceasingly isolated due to loss of habitat and are now largely confined to scattered sinkholes, springs, manmade impoundments, streams, and marshes.
The Devil’s River
The Devil’s River is located in south-western Texas.
The Devil’s River minnow (Dionda diaboli) historically occurred in tributaries of the Rio Grande in south-western Texas and Coahuila, northern Mexico. It has since been extirpated from much of this area, and is currently known for certain only from three streams in Val Verde and Kinney counties, Texas (Devil’s River, San Felipe Creek, and Pinto Creek).
The Conchos River
The Conchos River (Rio Conchos in Spanish) is located in northern Mexico (Chihuahua and Durango). The Rio Grande’s largest tributary, it is also the only free-flowing large river environment left within the Rio Grande drainage basin. Its river, spring, and cave habitats support a high number of endemic species and remain relatively intact, although dams, pollution, and occasional droughts are ongoing threats.
The Conchos shiner (Cyprinella panarcys) is a type of minnow confined to a few localities within the upper Conchos River drainage.
The Conchos darter (Etheostoma australe) is confined to a few localities within the upper Conchos River drainage.
The Salado River
The Salado River (Río Salado in Spanish) is located in northeastern Mexico (Nuevo León and Coahuila).
The Salado shiner (Notropis saladonis) was known from four localities within the Salado River drainage, where it seems to have gone extinct by the late 1980s.
The marbled swordtail (Xiphophorus meyeri) was endemic to freshwater springs and small creeks in the Salado River drainage, where it was extirpated by the late 1990s due to overextraction of water. Fortunately, a captive population survives at Texas State University.
The San Juan River
The San Juan River is located in north-eastern Mexico (Nuevo León and Coahuila).
The Monterrey platyfish (Xiphophorus couchianus) historically occurred in a number of endothermal springs within the upper San Juan River drainage. As a result of habitat destruction and degradation it is now confined to a single natural locality (the Ojo de Agua de Apodaca), where only hybridized specimens remain. Fortunately, a small number of pure specimens survive in captivity and reintroductions are planned once suitable habitat can be recovered.
The Salinas River (Río Salinas in Spanish) is located in north-eastern Mexico (Coahuila).
The Chorro chub (Gila modesta) is confined to a single stream within the Salinas River drainage.
The Colorado River
The Colorado River is one of the principal rivers of the southwestern United States and northern Mexico. Its 2330-km course begins in the central Rocky Mountains of Colorado and flows generally south-west to, at least historically, the Gulf of California, draining an expansive, arid watershed in the process. The river and its tributaries are controlled by an extensive system of dams, reservoirs, and aqueducts, which in most years divert its entire flow for agricultural irrigation and domestic water supply. This consumption has dried up the lower 160 km of the river, which has rarely reached the sea since the 1960s.
The relict leopard frog (Lithobates onca) was historically found along the Colorado River in extreme north-western Arizona, southern Nevada and south-western Utah, where it lived in freshwater springs and their outlets. Long threatened by habitat loss due to agricultural and water development as well as invasive species, it now appears to be confined to the Lake Mead National Recreation Area.
The Apache trout (Oncorhynchus apache) is restricted to two small streams on the Fort Apache Indian Reservation in Arizona. Previously this fish was widespread in tributaries of the White and Colorado rivers, but the introduction of competing species and modification of the habitat by deforestation long ago wiped out these populations.
The Colorado pikeminnow (Ptychocheilus lucius) is the largest North American minnow. Historically widespread, by the mid-1980s this species occurred only in the upper Colorado drainage. Wild fish have not been seen below Glen Canyon Dam since 1968.
The loach minnow (Tiaroga cobitis) was historically abundant throughout much of the Verde, Gila, Salt, San Pedro, and San Francisco rivers of Arizona, New Mexico, and Sonora, but is now reduced to small, isolated populations. It is now thought to have been extirpated in Mexico due to loss of habitat.
Several chubs of the genus Gila endemic to the Colorado River drainage are threatened by habitat destruction and degradation. The humpback chub (G. cypha) formerly occurred throughout much of the Colorado River from western Colorado and south-western Wyoming to northern Arizona (and perhaps California). The upper range along the Utah– Wyoming border was significantly altered by construction of the Flaming Gorge Dam in the early 1960s. Currently, only a few populations survive in the Grand Canyon area. The bonytail chub (G. elegans) was once abundant throughout the Colorado River and its larger tributaries, but has now been extirpated from many areas. Restocking efforts in Arizona have been successful. The semi-nude chub (G. seminuda) is confined to the Virgin and Muddy (= Moapa) rivers. The roundtail chub (G. robusta), along with an indeterminate number of ill-defined subspecies, is confined to the Colorado River drainage.
The southern leatherside chub (Lepidomeda aliciae) is found patchily in sluggish pools, creeks and small rivers within the Bonneville Basin of Utah, where it is threatened by loss of habitat and introduced fish species.
The Independence Valley tui chub (Siphateles bicolor isolata) was endemic to the drainage of the Independence Valley in northern Nevada. Described as abundant when first collected in 1965, it was extinct within less than a decade due to the introduction of exotic fish species into the watershed.
The woundfin (Plagopterus argentissimus) is a type of minnow that was historically found in the Colorado and Gila River drainages in Arizona, Nevada, and Utah. The species is today functionally extinct in the wild and maintained only by hatchery-raised individuals.
The desert pupfish (Cyprinodon macularius) was historically found throughout the south-western United States and north-western Mexico, but has been extirpated from most of its former range due to habitat destruction and introduced fish species. The only remaining natural populations are located at a few localities within the Salton Sea drainage of California and in the Colorado River delta of Baja California and Sonora.
The razorback sucker (Xyrauchen texanus) historically occurred throughout the Colorado River drainage, but has been much reduced in range. It is now restricted to the Colorado River upstream of the Grand Canyon and to four lakes (Mead, Mohave, Havasu, and Powell).
The Little Colorado River
The Little Colorado River is located in north-eastern Arizona.
The Little Colorado spinedace (Lepidomeda vittata) formerly occurred throughout the upper sections of the Little Colorado, but is now largely confined to disjunct tributary creeks.
The Virgin River
The Virgin River runs through south-western Utah, northwestern Arizona, and south-eastern Nevada, where it empties into Lake Mead.
Two subspecies of Virgin River spinedace (Lepidomeda mollispinis) are confined to the Virgin River drainage. The nominate form (L. m. mollispinis) has been much reduced in range and abundance by loss of habitat and introduced species.
The Muddy (Moapa) River and its tributaries are located in southern Nevada and flow into Lake Mead.
The Moapa dace (Moapa coriacea) is confined to the warm spring area at the headwaters of the Moapa River in southeastern Nevada.
Three spinedace (Lepidomeda) were historically endemic to the White River drainage, a tributary of the Moapa River located in south-eastern Nevada. The Pahranagat spinedace (L. altivelis) was confined to outflows from springs and a single lake in the Pahranagat Valley, Nevada. The last recorded collections were made in 1938, and a search in 1959 failed to find any. The extinction was likely due to competition with introduced species. The White River spinedace (L. albivallis) is confined to a single spring complex in the upper White River. The Big Spring spinedace (L. mollispinis pratensis) is entirely confined to a section of Meadow Valley Wash.
The Moapa springfish (Crenichthys baileyi) is divided into five subspecies, all of which are confined to isolated warm springs within the Moapa River and its tributaries. Bailey’s springfish (C. b. baileyi) is confined to a spring pool within Ash Springs. The Moapa springfish (C. b. moapae) is confined to the headwater springs of the Moapa River. The Preston springfish (C. b. albivallis) is confined to spring remnants of the uppermost White River. The Hiko springfish (C. b. grandis) is native to Crystal and Hiko springs, but has also been introduced to Blue Link Spring. The Moormon springfish (C. b. thermophilus) is confined to the Moorman and Moon River springs, and to Hot Creek.
The Pahranagat roundtail chub (Gila robusta jordani) is confined to small streams along the White River.
The Gila River
The Gila River is located in south-western New Mexico, southern Arizona, and north-western Mexico (Sonora). It is one of the larger tributaries of the Colorado River.
The Gila trout (Oncorhynchus gilae) is confined to small mountain streams and pools in Gila River drainage, where it receives some protection within the Gila National Forest.
The Gila chub (Gila intermedia) historically occurred in springs and small streams within the upper Gila River drainage, but has now been reduced to small, remnant populations.
The spikedace (Meda fulgida) is confined to a few fastmoving streams within the Gila River drainage.
The Yaqui River
The Yaqui River (Río Yaqui in Spanish) is located primarily in north-western Mexico (Chihuahua and Sonora), extending into extreme south-eastern Arizona.
The Yaqui chub (Gila purpurea) is confined to parts of the Yaqui River drainage in south-eastern Arizona, as well as to a short perennial reach of the San Bernardino River in Sonora. The species was nearly extirpated in the United States by the mid-1970s, surviving only in a single artesian well, but has since been introduced to a few creeks and ponds.
The whitefin pupfish (Cyprinodon albivelis) is known from the upper Papigóchic River and other tributaries and spring complexes within the Yaqui River in north-western Mexico (Sonora). It is threatened by pollution and drought.
The Bavispe River
The Bavispe River is one of the larger tributaries of the Yaqui River.
The Bavispe topminnow (Poeciliopsis sonorensis) is known from the Bavispe River drainage in southern Arizona and north-western Mexico (Sonora). It is threatened by loss of habitat and introduced species.
The Bavispe sucker (Catostomus leopoldi) is confined to the headwaters of the Bavispe River.
Miscellaneous Lakes, Rivers, and Marshes
The Warner Lakes are a chain of shallow lakes and marshes in the Warner Valley, south-central Oregon. The lakes extend the length of the valley.
The Warner sucker (Catostomus warnerensis) is found in the Warner Lake basin and in adjacent north-eastern California and north-western Nevada. This range includes three permanent lakes (Hart, Crump, and Pelican), a number of ephemeral ones, as well as sloughs, canals, and streams. Populations fluctuate according to water availability.
Alvord Lake is a shallow, seasonal, high-elevation alkali lake located in south-eastern Oregon.
The Alvord cutthroat trout (Oncorhynchus clarkii alvordensis) is an extinct subspecies known only from Trout Creek in Oregon and Virgin Creek in Nevada, although it may have historically occurred in several other Alvord Lake basin streams.
Borax Lake is an alkali lake in the Alvord Desert of southeastern Oregon, fed by geothermal springs deep below the surface. Its waters range in temperature from 16 to 38°C but occasionally go higher, and contain high concentrations of sodium borate, arsenic, and lead.
A unique endemic species, the Borax Lake chub (Siphateles boraxobius), is found in outflows and pools around the lake. Small numbers are found as well in Little (or Lower) Borax Lake, but die off each year due to seasonal drying.
Clear Lake is a large freshwater lake located in northern California.
The Clear Lake splittail (Pogonichthys ciscoides) was historically confined to Clear Lake and its tributary streams. Last collected in 1970, it is now extinct.
Twin Lake is located in Colorado.
The yellowfin cutthroat trout (Oncorhynchus clarkii macdonaldi) was endemic to Twin Lake, where it became extinct some time after 1903 due to the introduction of rainbow trout (O. mykiss).
Bear Lake is a natural freshwater lake in the Wasatch Range, on the Utah–Idaho border. Its unusual water properties give it a distinct turquoise colour.
The Bear Lake sculpin (Cottus extensus) was historically endemic to Bear Lake, although a population has been introduced to the Flaming Gorge Reservoir in Utah and Wyoming.
Miller Lake is a large freshwater lake in the Cascade Range of western Oregon.
The Miller Lake lamprey (Entosphenus minimus) was last collected from the lake in the early 1950s, but survives in a few small rivers and creeks.
Lake Mayrán (Laguna de Mayrán in Spanish) is located in north-central Mexico (Coahuila).
The Parras pupfish (Cyprinodon latifasciatus) was endemic to the Laguna de Mayrán basin. It is now extinct.
The Umpqua River is one of the principal rivers of the Oregon coast. It is formed by the confluence of the North and South Umpqua rivers, and flows to the Pacific.
The Umpqua chub (Oregonichthys kalawatseti) is confined to middle and upper courses of tributaries in the Umpqua River drainage.
The Brazos River runs from New Mexico through Texas to the Gulf of Mexico.
Two small species of freshwater fish, the smalleye shiner (Notropis buccula) and the sharpnose shiner (N. oxyrhynchus) are confined to the Brazos River.
The Nueces River is located in south-central Texas.
The plateau shiner (Cyprinella lepida) is a type of minnow confined to springs and headwater creeks in the Nueces River drainage.
The Guadalupe River is located in south-central Texas.
Cagle’s map turtle (Graptemys caglei) is confined mainly to the lower 120 km of the Guadalupe River.
The James River is located in Virginia.
The roughhead shiner (Notropis semperasper) is confined to the upper James River drainage.
The Bayou du Chien is a stream located in western Kentucky.
The relict darter (Etheostoma chienense) is confined to the Bayou du Chien drainage.
The Cape Fear River is located in the south-eastern United States (North Carolina).
The Cape Fear shiner (Notropis mekistocholas) is confined to the Cape Fear River drainage.
The Suwannee River is located in the south-eastern United States (Georgia and Florida).
The Suwannee alligator snapping turtle (Macrochelys suwanniensis) is confined to the Suwannee River.
The Snake River is located in Wyoming, Idaho, Oregon, and Washington states. It is the largest tributary of the Columbia River.
The Snake River sucker (Chasmistes muriei) is known only from a single specimen collected below Jackson Lake Dam. It is now considered extinct, although the reason remains unknown.
The Susquehanna River is located in the north-eastern and mid-Atlantic region (New York, Pennsylvannia, and Maryland). It is the longest river in the eastern United States.
The Maryland darter (Etheostoma sellare) was known only from tributaries of the lower Susquehanna River in Maryland. By the 1980s it was restricted to Deer Creek, where it was last reported in 1986. It is now most likely extinct.
The Sonora River (Río Sonora in Spanish) is located in north-western Mexico (Sonora).
The Opata sucker (Catostomus wigginsi) is confined to the Sonora River drainage, where it is threatened by water extraction, pollution, and introduced species.
Coasts and Satellite Islands
The coasts around North America are marked by a tremendous variety of habitats: islands, cliffs, estuaries, deltas, tidal marshes, sand beaches, coral reefs, mangrove forests, and so on. Animal life varies in relation to these habitats. It is chiefly in California and Mexico that coastal and island animals of North America have been exterminated or seriously reduced in numbers. Some belong to the mainland coast, but most of them live on islands.
The northern elephant seal (Mirounga angustirostris) lives along the eastern Pacific coasts where it spends most of its time at sea, only coming to land at certain times to breed in remote rookeries. During the nineteenth century these creatures were ruthlessly hunted for the oil in their blubber. They were thought to be extinct in 1884 until a remnant population of eight individuals was discovered on Guadalupe Island in 1892 by a Smithsonian expedition, who promptly killed seven of them for their collections. The elephant seals managed to survive, and were finally protected by the Mexican government in 1922. The species has since recovered its former range and numbers.
The northern fur seal (Callorhinus ursinus) is also once again widely distributed in the misty ocean waters of the North Pacific (including the Bering Sea and Sea of Okhotsk), after having almost been driven to extinction during the nineteenth century by hunting. The species was first observed off Bering Island in 1741, but it would be almost half a century before its breeding grounds were discovered. In 1786 the Russian explorer Gerasim Pribilof, sailing among the group of islands that would later be named for him, came upon the greatest concentration of marine mammals ever observed, at least by Europeans. Millions of fur seal bulls, cows and pups covered the beaches and rocks of what is now St. George Island. About a year later another island in the group, St. Paul, was discovered to have even more seals than the previous one. The exploitation of the species was begun almost immediately by the Russians, and within 20 years the enormous herds had been so sharply reduced that the species had begun to be threatened. In 1834 it was decreed that only mature bulls could be killed, a measure that saved it. In 1864 the population was still estimated at between two and three million and yielded between 80,000 and 90,000 bulls every year, seemingly without any drastic effect. When in 1867 the United States bought Alaska from Russia, the fur trade was taken over by Americans. In 1870 the United States limited the number shot to 100,000 seals each year. However, Canadian and British sealers continued to shoot the species indiscriminately on the open sea. Moreover, the majority of these dead seals sank beneath the waves before they could be secured. The annual harvest in the Pribilof Islands dropped continuously, and in 1910 only 12,000 pelts were taken. Fortunately, the American government arranged an international treaty in 1911 that banned all sealing in open waters. From a low of about 125,000 seals, the population increased until it at last returned to its former abundance. At present about half of these breed in the Pribilof Islands, with the remaining larger colonies located in the Commander Islands, Tyuleniy Island off the coast of Sakhalin, and the central Kuril Islands. Smaller rookeries are found in the Aleutians, and on San Miguel Island and South Farallon Island off the coast of California. During the winter months the animals may be seen as far south as the southern tip of Japan and the Baja California Peninsula. The Guadalupe fur seal (Arctocephalus townsendi) was originally found off California and Mexico from the Farallon Islands in the north to the San Benito Islands in the south. During the late eighteenth and early nineteenth centuries it was avidly hunted for skins and oil. In 1810, for example, a party of only eight men killed 33,740 seals on the Farallon Islands; the next year they took 21,153; and in 1812 the catch was 18,509. By 1826 this seal was almost extinct on the Farallons. The most important remaining population was that of Guadalupe Island, where about 30,000 fur seals still survived. They decreased rapidly: in 1880 there were 3000–4000 seals and by 1892 only 7 seals were left, the last seen in that century. Commercial sealing was finally banned in Mexico in 1894. For 30 years the Guadalupe fur seal was considered extinct, but in 1928 a fisherman captured two specimens and reported that he had seen a herd of about 60 animals on Guadalupe. But searchers could not locate them. In 1950 Professor George Bartholomew visited San Nicolas Island off southern California and discovered one Guadalupe fur seal. This lone specimen was observed several times between 1949 and 1951. In 1954 a breeding colony of 14 seals was seen at Guadalupe. In 1965 the population was reported to be between 200 and 500, and in 1972 at least 500. The species has now recovered thanks to protection, but the eastern coast of Guadalupe remains its only major breeding site.
The sea mink (Neovison macrodon), at the arrival of the Europeans, occurred along the mainland coast and islands of the north-east from Massachusetts to Newfoundland. Because of its large size and valuable fur, it was hunted avidly. Skins were procured regularly until about 1860, and then the number shrank rapidly. It is thought to have survived until about 1894 in New Brunswick.
The San Lorenzo deer mouse (Peromyscus interparietalis) is confined to three small islands (Salsipuedes, Las Animas, and San Lorenzo) located in the Gulf of California off the eastcentral coast of the Baja California Peninsula.
The Florida bonneted bat (Eumops floridanus) is known only from a few scattered localities along the south-eastern and south-western coasts of Florida, where it is threatened by habitat destruction and alteration (i.e., the removal of old trees with cavities suitable for roosting), as well as pesticide use.
The fish-eating mouse-eared bat (Myotis vivesi) is largely restricted to a few islands in the northern Gulf of California, with a few colonies as well along the Sonora and Baja California Peninsula coasts.
The brown pelican (Pelecanus occidentalis) is a coastal bird with an extremely large range across the southern southern United States, Caribbean, and northern Latin America. Like the bald eagle (Haliaeetus leucocephalus) it was at one time seriously threatened in some areas owing to the use of pesticides such as DDT and dieldrin. When the latter began to be banned in the 1970s populations recovered fairly quickly. It is interesting to note that, in 1903, Theodore Roosevelt set aside Pelican Island in Florida as the nation’s very first national wildlife refuge in order to protect this species from hunters.
The marbled murrelet (Brachyramphus marmoratus) is a small seabird that breeds along the the western coast of North America and a few satellite islands, where it is threatened mainly by loss of its forest-nesting habitat.
Craveri’s murrelet (Synthliboramphus craveri), Scripp’s murrelet (S. scrippsi), and the white-mantled murrelet (S. hypoleucus) all breed on islands off the coast of California and north-western Mexico, where they are threatened by introduced predators within their colonies and by the potential for oil spills.
The ashy storm petrel (Hydrobates homochroa) is a rare type of small seabird that breeds colonially on islands and rocks off the coast of California and north-western Mexico, with half of the population nesting only on the Farallon Islands near San Francisco. Leach’s storm petrel (H. leucorhous) is divided into two subspecies. The nominate form (H. l. leucorhous) breeds along both the North Pacific and North Atlantic coasts, mainly on inaccessible islands. The Baja California Leach’s storm petrel (H. l. chapmani) breeds only on Coronados and San Benito Island off the western coast of Mexico. All are threatened mainly by nest predation from both native and invasive species.
The red-legged kittiwake (Rissa brevirostris) is a type of gull that breeds on a few islands in the Bering Sea off the coasts of Alaska and Russia, spending its winters mainly at sea. It has undergone declines due to reductions in the availability of fish.
The Labrador duck (Camptorhynchus labradorius) is an extinct species whose historical breeding range and precise habitat are unknown. It most likely bred along the Gulf of St. Lawrence and in coastal Labrador, Canada, and wintered from Nova Scotia south to Florida. Shooting, trapping, and overharvesting of its eggs had already rendered it rare by the beginning of the nineteenth century, and the last known specimen was shot off Long Island in 1875 or possibly 1878.
The heath hen (Tympanuchus cupido cupido) was a type of greater prairie chicken historically found in the scrubby heathland barrens of the coastal eastern United States from southernmost New Hampshire to the Potomac River in Washington, DC, and possibly as far south as Florida prehistorically. Intensively hunted, it was exterminated from the mainland by around 1840 and from then on entirely restricted to the island of Martha’s Vineyard, south of Cape Code, Massachusetts. It was there that the subspecies finally became extinct in 1932.
The spiny chuckwalla (Sauromalus hispidus) is a type of lizard historically confined to Ángel de la Guarda Island in the Gulf of California, from where it was transported long ago by a Native American tribe to a number of other islands as a food source. It is threatened mainly by invasive species, in particular feral cats.
The Baja whiptail lizard (Aspidoscelis labialis) is confined to a narrow band along the western coast of the Baja California Peninsula, Mexico.
The Baja legless lizard (Anniella geronimensis) is confined to coastal sand dunes within a small area of the north-western Baja California Peninsula, Mexico, including San Gerónimo Island.
Barbour’s whip snake (Masticophis barbouri) is confined to Espiritu Santo and Partida Sur off the south-eastern coast of the Baja California Peninsula.
Coastal salt marshes are among the most threatened habitats worldwide due to their limited natural extent, long history of human modification, and anticipated sea level rise due to climate change.
Two subspecies of salt marsh harvest mouse (Reithrodontomys raviventris) are restricted to the San Francisco Bay area. The nominate form (R. r. raviventris) inhabits the San Pablo Bay area, while R. r. halicoetes occupies the Suison Bay end. Both are threatened by habitat destruction.
The Florida salt marsh vole (Microtus pennsylvanicus dukecampbelli) was, to judge by fossil material, historically widespread throughout the south-eastern United States, but has been reduced by climatic changes to a single salt marsh in Waccassasa Bay, north-western Florida.
The dusky seaside sparrow (Ammodramus maritimus nigrescens) was confined to some small salt marshes on Merritt Island and along the St. Johns River near the Kennedy Space Center in Florida. In 1968 the total population of this non-migratory bird was around 1000, and it was thought that security regulations in the area had improved its chances for survival, because it was less disturbed. Unfortunately, when Merritt Island was flooded with the goal of reducing the mosquito population the sparrow’s nesting grounds were devastated. Later, the marshes surrounding the river were drained to facilitate highway construction. Pollution and pesticides also took a toll. By 1979 only six were known to exist, all of whom were males. The last known individual died in captivity in 1987. Another subspecies, the Cape Sable seaside sparrow (A. m. mirabilis), was long thought to be extinct as well, a victim of hurricanes and fires. In 1970, however, it was rediscovered in the coastal prairie along the shores of Cape Sable in Everglades National Park. Additional populations have since been found in Big Cypress Swamp and elsewhere.
The salt marsh sparrow (Ammospiza caudacuta) is divided into two subspecies. The northern salt marsh sparrow (A. c. caudacuta) breeds from Maine to New Jersey, while the southern salt marsh sparrow (A. c. diversus) breeds in Maryland and Virginia. Both are threatened by loss of habitat.
The diamondback terrapin (Malaclemys terrapin) is widely but narrowly distributed in the brackish coastal tidal marshes of the eastern and southern United States and Bermuda (where it arrived on its own rather than being introduced by humans). During the nineteenth and early twentieth centuries it was widely used for ‘turtle soup’ and collected almost to extinction. Development of coastal areas also caused reductions in populations. However, the species is once again relatively common in some areas. The northern diamondback terrapin (M. t. terrapin) is found in coastal Connecticut, Delaware, Maryland, Massachusetts, New Jersey, New York, North Carolina, Rhode Island, and Virginia. The Carolina diamondback terrapin (M. t. centrata) is found in coastal Georgia, Florida, and the Carolinas. The Texas diamondback terrapin (M. t. littoralis) is found in coastal Texas. The Mississippi diamondback terrapin (M. t. pileata) is found in coastal Alabama, western Florida, Louisiana,Mississippi, and Texas. The East Florida diamondback terrapin (M. t. tequesta), mangrove diamondback terrapin (M. t. rhizophorarum), and ornate diamondback terrapin (M. t. macrospilota) are all found in small areas of the Florida coast.
The Pribilof Islands
The Pribilof Islands are a group of four remote, volcanic islands located off the coast of Alaska.
The Pribilof shrew (Sorex pribilofensis) is confined to Saint Paul Island, where the population appears to be stable.
The Aleutian Islands
The Aleutians are a chain of 14 large, volcanic islands and 55 smaller ones, located south of Alaska in the northern Pacific.
The Aleutian cackling goose (Branta hutchinsii leucopareia) is a small subspecies that now nests only on the islands of Amchitka and Buldir in the Aleutian Islands. Historically found throughout the Aleutians as well as on the Komandorski and Kuril Islands, it was extirpated from most of its breeding range by intensive hunting and introduced arctic foxes (Vulpes lagopus). However, the overall population is not considered to be threatened.
The Umnak collared lemming (Dicrostonyx unalascensis) is confined to the islands of Umnak and Unalaska. Although common, it is nevertheless vulnerable to outside threats.
The Alexander Archipelago
The Alexander Archipelago is a 480-km-long group of islands located off the south-eastern coast of Alaska. It includes some 1100 islands, which are in fact the tops of submerged coastal mountains rising steeply from the ocean floor.
The Sitka brown bear (Ursus arctos sitkensis) is confined to Admiralty, Baranof, and Chichagof islands.
Located on the south-western coast of Canada in the northeastern Pacific, Vancouver Island is the largest island on the western coast of North America.
The Vancouver Island grey wolf (Canis lupus crassodon) is confined to northern Vancouver Island.
The Vancouver Island marmot (Marmota vancouverensis) is confined to the mountains of central and southern Vancouver Island.
The Vancouver Island lake lamprey (Entosphenus macrostoma) is found only in Cowichan and Mesachie lakes (which are connected) and their in-flowing tributaries on southern Vancouver Island.
The Channel Islands
The Channel Islands are a chain of eight islands located off the coast of southern California. Five of them make up the Channel Islands National Park, with the surrounding islands protected as a marine sanctuary. They are home to a number of endemics, a few of which are threatened.
The Channel Islands spotted skunk (Spilogale gracilis amphiala) was historically known from Santa Cruz, Santa Rosa, and San Miguel, but has since been extirpated from the latter island. It is threatened by habitat destruction and predation by dogs and cats.
The Santa Cruz mouse (Peromyscus sejugis) is confined to Santa Cruz and San Diego islands.
Santa Cruz Island
Santa Cruz (Isla Santa Cruz in Spanish) is the largest of the Channel Islands.
The Santa Cruz scrub jay (Aphelocoma insularis) is confined to Santa Cruz Island.
San Clemente Island
Santa Cruz (Isla San Clemente in Spanish) is the southernmost of the Channel Islands.
The San Clemente loggerhead shrike (Lanius ludovicianus mearnsi) is confined to San Clemente, where it was long threatened by loss of habitat due to feral goats and sheep. By the early twentieth century the total population had been reduced to around 20. In 1973 the U.S. Navy began to remove the goats and sheep, a process that was finally completed in 1993. The total number of birds remains low, however, and vulnerable to drought.
Guadalupe Island (Isla Guadalupe in Spanish) is located about 280 km off the Baja California Peninsula. Surrounded by deep waters, it has a rugged landscape consisting of two ancient overlapping shield volcanoes. Virtually all the native shrubs, many of them endemic, have disappeared and have been replaced by introduced grasses. Sparse groves of native trees, mostly cypresses, pines, oaks, and palms, still exist on the northern ridge and slopes. There are no terrestrial mammals, reptiles, or amphibians on the island, but there are birds, and these have declined greatly. No fewer than five taxa have become extinct primarily due to habitat destruction by goats, which in turn rendered the birds more vulnerable to predation by introduced cats and to adverse weather. The island was a also major destination for Russian and American fur hunters seeking the Guadalupe fur seal (Arctocephalus townsendi) and northern elephant seal (Mirounga angustirostris) during the eighteenth and nineteenth centuries, until both were nearly extinct by 1844. Captain Auguste Duhaut-Cilly reported in 1827 that a Sandwich Islands (Hawaiian Islands) brig ‘had spent several months there and collected three thousand sealskins’. Nevertheless, in stark contrast to the rampant extinction of terrestrial life that happened at the same time, Guadalupe was ultimately to be the last refuge for the latter two species in the 1890s.
The Guadalupe storm petrel (Hydrobates macrodactylus) was abundant in 1906, but declined dramatically thereafter owing to predation by cats. The last record of a breeding bird was in 1912. Searches in 1922, 1925, and in the early 1970s failed to find any. However, it is thought that a small number, perhaps fewer than 50, may still survive in inacessible areas. Townsend’s storm petrel (H. socorroensis) is only known to breed on the tiny islets of Islote Negro and Islote Afuera, although it is possible that it may do so as well on Guadalupe itself. Its pelagic distribution is not known but the birds probably range from southern California to the coast of Central America. Ainley’s storm petrel (H. cheimomnestes) breeds on the islets of Islote Negro, Islote Afuera, and on Gargoyle Rock, from where it likely disperses from the Baja California Peninsula southward to the Galápagos Islands.
The Guadalupe caracara (Caracara lutosa) was a bird of prey that was intentionally driven to extinction in 1903 by settlers, owing to the fact that it occasionally preyed on young goats.
The Guadalupe red-shafted flicker (Colaptes auratus rufipileus) became extinct between 1906 and 1922. The island was later recolonized by individuals of the nominate subspecies.
The Guadalupe spotted towhee (Pipilo maculatus consobrinus) was exterminated in 1897.
The Guadalupe Bewick’s wren (Thryomanes bewickii brevicauda) was exterminated in 1897.
The Guadalupe junco (Junco insularis) was historically quite common but is now patchily distributed in the north of the island.
The Guadalupe ruby-crowned kinglet (Regulus calendula obscurus) was not observed in 2000 despite thorough searches, and is now considered extinct.
The Coronado Islands
The Coronado Islands (Islas Coronado in Spanish) are a group of four barren, uninhabited islands off the north-western coast of the Baja California Peninsula.
Bunker’s woodrat (Neotoma bryanti bunkeri) is known only from five specimens collected in 1932. It is now considered extinct, a likely victim of predation by feral cats.
The Coronados deer mouse (Peromyscus pseudocrinitus) is known only from Coronados Island, where it is thought to be near extinction.
The Todos Santos Islands
The Todos Santos Islands (Islas Todos Santos in Spanish) are a pair of islands about 20 km off Ensenada, Baja California.
The Todos Santos woodrat (Neotoma bryanti anthonyi) was known only from the Todos Santos Islands, where it was last recorded in 1926. It is most likely extinct.
The Todos Santos rufous-crowned sparrow (Aimophila ruficeps sanctorum) is known only from the Todos Santos Islands, where it is most likely extinct.
The Todos Santos kingsnake (Lampropeltis zonata herrerae) is confined to the Todos Santos Islands.
Cedros Island (Isla de Cedros in Spanish) is a dry and rocky island located off the central-west coast of the Baja California Peninsula.
The Cedros mule deer (Odocoileus hemionus cerrosensis) is confined to Cedros Island, where the total population of around 50 is threatened by poaching and feral dogs.
The Cedros woodrat (Neotoma bryanti bryanti) is confined to Cedros Island.
San Pedro Nolasco Island
San Pedro Nolasco Island (Isla San Pedro Nolasco in Spanish) is located in the Gulf of California off the central coast of the Baja California Peninsula. It is protected as a nature reserve.
Pemberton’s deer mouse (Peromyscus pembertoni) was last collected in 1931 and is now extinct.
The San Pedro Nolasco spiny-tailed iguana (Ctenosaura nolascensis) is confined to the island.
San Marcos Island
San Marcos Island (Isla San Marcos in Spanish) is located in the Gulf of California off the central coast of the Baja California Peninsula.
The San Marcos woodrat (Neotoma bryanti macrosensis) is confined to San Marcos Island.
The San Marcos night snake (Hypsiglena sleveni marcosensis) is known only from a few specimens collected on San Marcos Island.
Santa Catalina Island
Santa Catalina (Isla Santa Catalina in Spanish; traditionally Isla Catalana) is an uninhabited island located off the south-eastern Baja California Peninsula.
Slevin’s deer mouse (Peromyscus slevini) is confined to Santa Catalina Island, where it is threatened by competition with the introduced northern Baja deer mouse (P. fraterculus).
The Santa Catalina whiptail lizard (Aspidoscelis catalinensis) is confined to Santa Catalina Island.
The Santa Catalina rattlesnake (Crotalus catalinensis) is a small species, notable for lacking a rattle. It is confined to Santa Catalina Island, where it is threatened by feral cats and overcollection for the international exotic pet trade.
The Santa Catalina kingsnake (Lampropeltis catalinensis) is confined to Santa Catalina Island.
The Revillagigedo Islands
The Revillagigedo Islands (Islas Revillagigedo in Spanish) are a group of four volcanic islands located approximately 390 km west off the southern tip of Baja California. Long isolation from the mainland has resulted in a number of endemic taxa on three of the islands (the fourth, Roca Partida, is too small to support terrestrial fauna), many of which are threatened by feral cats, exotic birds, and introduced sheep, pigs, and rabbits. The islands were designated a biosphere reserve in 1994. Townsend’s shearwater (Puffinus auricularis) is a type of seabird that historically bred on Socorro, Clarión, and San Benedicto, ranging more widely off the western coast of Mexico at other times. It was extirpated from San Benedicto during the 1950s and from Clarión by the late 1980s, and now breeds only in one area on Socorro, where it is threatened by feral cats.
Socorro (Isla Socorro in Spanish) is the largest of the Revillagigedo Islands. Consisting of a large shield volcano rising abruptly from the sea to an elevation of 1050 m, it last erupted in 1993.
The Socorro elf owl (Micrathene whitneyi graysoni) became extinct around 1970.
The Socorro dove (Zenaida graysoni) was historically common on Socorro but was last recorded in the wild in 1972. Fortunately, several individuals were collected during an expedition in 1925 and subsequently bred in captivity in the United States and Europe.
The Socorro green parakeet (Psittacara holochlorus brevipes) is confined to Socorro, where it is highly threatened by habitat destruction and degradation.
The Socorro mockingbird (Mimus graysoni) is endemic to Socorro where, in 1925, it was reported to be the island’s most abundant and widespread landbird. By 1978, however, the species had declined dramatically due to the overgrazing of sheep which destroyed much of its habitat and was feared to be on the verge of extinction. The sheep have now been eradicated from the island, but the birds have so far shown little sign of recovery.
The Socorro towhee (Pipilo socorroensis) is a type of sparrow confined to Socorro.
The Socorro tree lizard (Urosaurus auriculatus) is confined to Socorro.
Clarión (Isla Clarión in Spanish; formerly known as Santa Rosa Island) is the westernmost and most remote of the Revillagigedo Islands. Two small and at least temporarily brackish pools are the only source of freshwater, and even these may dry up in summers with little rain.
The Clarión mourning dove (Zenaida macroura clarionensis) is confined to Clarión.
The Clarión wren (Troglodytes tanneri) is confined to Clarión, where the total population is thought to be less than 400.
The Clarión tree lizard (Urosaurus clarionensis) is confined to Clarión.
The Clarión whip snake (Masticophis anthonyi) is confined to Clarión.
The Clarión night snake (Hypsiglena unaocularus) was long known only from a single specimen collected by naturlist William Beebe in 1936. A small number were rediscovered in 2013.
San Benedicto (Isla San Benedicto in Spanish) is the third largest of the Revillagigedo Islands. Now uninhabited, a devastating eruption on the morning of 1 August 1952 wiped out, at least temporarily, all flora and terrestrial fauna on the island.
The San Benedicto rock wren (Salpinctes obsoletus exsul), which was endemic to the island, was one of the aforesaid victims of the 1952 eruption.
Newfoundland is a large island located off the eastern coast of Canada.
The Newfoundland grey wolf (Canis lupus beothucus) was reported to be common in 1875 on Newfoundland, where it fed mainly on caribou and rodents. Unfortunately, it also preyed upon young cattle, and therefore a bounty was put on it. By the end of the nineteenth century it had been decimated, and the last specimen was killed about 1911.
The Newfoundland caribou (Rangifer tarandus terraenovae) is confined to the woodlands of Newfoundland.
Bermuda is a subtropical volcanic island about 1070 km eastsouth- east of Cape Hatteras, North Carolina, near the western edge of the Sargasso Sea.
The Bermuda petrel (Pterodroma cahow) is a mediumsized, nocturnal seabird that was historically quite abundant on the island, forming dense, noisy colonies. The crews of visiting Spanish ships in the late sixteenth and early seventeenth centuries caught thousands of them, which they called ‘cahow’ owing to the eerie sounds that they made, during their brief stopovers. They also brought feral pigs with them, which decimated the ground-nesting birds. By the time Bermuda was occupied by the English in 1612 the species was already rare. The latter brought with them new introduced species (rats, cats, and dogs), and their mass killing of the birds for food, coupled with burning of vegetation and deforestation, all but completed the extermination. No scientific description of the cahow was made until 1916, when some bones were found in a cave, and the species was generally believed to have been extinct for three centuries (a live specimen had actually been captured in 1906, but wrongly identified). In 1935, however, one unexpectedly struck a lighthouse on Bermuda and was subsequently sent to the noted zoologist William Beebe for identification. Six years later a live individual had been examined by a naturalist on the island. Finally, in 1951, about 100 birds (including 18 nesting pairs) were found on four, rat-free islets of the Castle Harbour Island group off southeastern Bermuda. This was soon declared a sanctuary, but by 1965 the population had nevertheless fallen to about 70, likely due to DDT contamination which the birds had picked up while feeding far out to sea, and which destroyed their eggs. With the banning of this pesticide numbers have once again increased, albeit slowly. In 2005 the total population was estimated at 250.
A number of bird species have become extinct on Bermuda owing to loss of habitat, hunting, and introduced predators. The Bermuda saw-whet owl (Aegolius gradyi), Bermuda hawk (Bermuteo avivorus), Bermuda night heron (Nyctanassa carcinocatactes), Bermuda flicker (Colaptes oceanicus), and Bermuda towhee (Pipilo naufragus) are all known only from fossil remains, but are believed to have survived into historic times.
The Bermuda rock skink (Plestiodon longirostris), the only indigenous land vertebrate on the island, is confined to a few localities on Bermuda and offshore islets.
The Florida Keys
The Florida Keys are a coral cay archipelago extending in a gentle arc southward from Florida into the Gulf of Mexico. The climate is subtropical but the flora and fauna are much influenced by the proximity of the tropics.
The Key deer (Odocoileus virginianus clavium) is the smallest of American deer. Even before historic time it was confined to these islands, occupying most of the lower keys. Wanton hunting, habitat destruction by real-estate developers, fires, and hurricanes brought down the number to about 25 by the mid-1950s. Since then legal protection, the establishment of the National Key Deer Refuge on Big Pine and No Name keys, and an effective education campaign has succeeded in raising the population to between 700 and 800, although it remains vulnerable.
The Key West bobwhite (Colinus virginianus insulanus) went extinct at some point during the twentieth century.
Muskeget Island, located between Martha’s Vineyard and Nantucket off the coast of Massachusetts, is low, sandy, and largely uninhabited.
The Muskeget beach vole (Microtus breweri) is found only on Muskeget Island. It is adapted to sandy habitats but its burrows, made in loose sand, do not give it much protection from cats, owls, and the elements.
The Queen Charlotte Islands are an archipelago approximately 45–60 km off the northern Pacific coast of Canada.
Dawson’s caribou (Rangifer tarandus dawsoni) was historically found on Graham Island, the largest of the Queen Charlotte Islands. A victim of overhunting, introduced disease, and habitat destruction, the last three were killed in 1908.
San Martín Island (Isla San Martín in Spanish) is located off the north-western coast of the Baja California Peninsula.
The San Martín woodrat (Neotoma bryanti martinensis) was endemic to the island, where it was historically abundant. It has not been recorded since the 1950s and is most likely extinct, a victim of predation by feral cats.
San Estaban Island (Isla San Esteban in Spanish) is located in the Gulf of California off the central-west coast of the Baja California Peninsula.
The San Esteban deer mouse (Peromyscus stephani) and the San Esteban chuckwalla (Sauromalus varius) are both confined to San Esteban Island.
The San Benito Islands (Islas San Benito in Spanish) are a group of three barren islands located off the southwestern coast of the Baja California Peninsula.
McGregor’s house finch (Haemorhous mexicanus mcgregori) was endemic to the San Benito Islands, where it became extinct during the 1940s due to overcollection by biological specimen hunters.
Ángel de la Guarda Island (Isla Ángel de la Guarda in Spanish) is one of the largest of the Gulf of California Islands. It is uninhabited and protected as a national park.
The Ángel de la Guarda deer mouse (Peromyscus guardia) was historically found on Ángel de la Guarda Island and three offshore islets (Mejía, Granito, and Estanque). Predation by feral cats and competition from introduced rodents has likely extirpated it from the three smaller islands (where it may have been represented by distinct subspecies), and perhaps on the main island as well.
Jacques Cousteau Island (Isla Jacques Cousteau in Spanish; formerly known as Cerralvo Island) is located off the southeastern Baja Califorina Peninsula.
Etheridge’s long-nosed snake (Rhinocheilus etheridgei) is confined to Jacques Cousteau Island.
San José Island (Isla San José in Spanish) is located off the eastern coast of the Baja California Peninsula.
The San José brush rabbit (Sylvilagus mansuetus) is confined to a small area of San José Island, where it is highly threatened by loss of habitat, hunting, and predation by feral cats.
Coloradito Island (Isla Coloradito in Spanish) is located off the north-eastern coast of the Baja California Peninsula.
The swollen-nosed side-blotched lizard (Uta tumidarostra) is confined to Coloradito Island.
Encantada Island (Isla Encantada in Spanish) is located off the north-eastern coast of the Baja California Peninsula.
The Encantada side-blotched lizard (Uta encantadae) is confined to Encantada Island and the adjacent rocks known as Islotes Blancos.
El Muerto Island is located off the north-eastern coast of the Baja California Peninsula. The El Muerto side-blotched lizard (Uta lowei) is confined to El Muerto Island.
San Pedro Mártir Island (Isla San Pedro Mártir in Spanish) is located in the Gulf of California off the central coast of the Baja California Peninsula. It is uninhabited and seldom visited.
The San Pedro Mártir whiptail lizard (Aspidoscelis martyris) and the San Pedro Mártir side-blotched lizard (Uta palmeri) are both confined to San Pedro Martir.
Tortuga Island (Isla Tortuga in Spanish) is a volcanic island located in the Gulf of California off the central coast of the Baja California Peninsula.
Dickey’s deer mouse (Peromyscus dickeyi) is confined to Tortuga Island.
Monserrate Island (Isla Monserrate in Spanish) is an uninhabited island located in the Gulf of California off the central coast of the Baja California Peninsula.
The Monserrate deer mouse (Peromyscus caniceps) is endemic to the island, where it is seriously threatened by feral cats.
Sable Island is a small, greatly elongated sand island located about 175 km south-east of Nova Scotia.
The Ipswich sparrow (Passerculus sandwichensis princeps) breeds almost exclusively on Sable Island and is decreasing in number, possibly owing to the erosion of its small island world.
Gull Island is located in Long Island Sound.
The Gull Island meadow vole (Microtus pennsylvanicus nesophilus) became extinct in 1898.
Block Island is located off Rhode Island.
The Block Island meadow vole (Microtus pennsylvanicus provectus) is confined to the island, where it is threatened by habitat destruction.
Anthropogenic effects on the flora and fauna
Modern humans, as previously noted, are relatively young in North America, having first crossed over from eastern Siberia via the Bering Sea land bridge into present-day Alaska between 40,000 and 17,000 years ago. In the beginning the ice sheet that then covered the continent confined these migrants to the north-west for thousands of years, although thereafter they were able to spread out to the east and south. In the beginning they certainly modified the environment in one way or another, at least locally, although without catastrophic results for the natural balance as a whole. It is true that a large number of mammals – not less than 41 species – became extinct across the continent during prehistoric times, but it remains uncertain to what extent humans were involved in this disaster. This early nomadic hunting period is taken to have lasted until about 10,000 years ago, after which a number of archaic subsistence cultures began to develop which lasted until around 1000 bc. After that sedentary farming developed, although hunting and gathering would continue well into the modern era. Many parts of North America are still populated by indigenous peoples to this day, often in relative isolation from Western culture.
Modern European exploration of North America began in the wake of Christopher Columbus’ four voyages during the late fifteenth century. In 1497, under the commission of Henry VII of England, the Italian explorer Giovanni Caboto (known as John Cabot) became the first European to explore the coast of mainland North America since the Norse did so five centuries earlier, visiting what is now Newfoundland. Successions of Portuguese, Spanish, Italian, French, English, and Dutch mariners would continue to map the eastern coast over the following decades, occasionally ascending rivers to explore ever further inland. Bermuda was first discovered in 1505 by the Spanish explorer Juan de Bermúdez, and in 1513 the Spanish conquistador Juan Ponce de León explored ‘La Florida’ (Florida). In 1519 the conquistador Alonzo Alvarez de Pineda sailed around the Gulf of Mexico and would be the first to reach the mouth of the Mississippi. In 1534 the French explorer Jacques Cartier undertook the first of his visits down the Gulf of St. Lawrence, reaching as far as present-day Montreal. Meanwhile, exploration of the Pacific coast had also begun, and by the 1530s Spanish sailors had reached the Baja California Peninsula and the Gulf of California, from where they would continue ever northwards. The first journeys into the interior of North America followed soon after. Between 1539 and 1543 an expedition led by the Spaniard Hernando de Soto explored much of the present-day southern United States, becoming the first to cross the Appalachians (over the Blue Ridge Mountains) and the Mississippi River. Between 1540 and 1542 the Spanish conquistador Francisco Vásquez de Coronado travelled overland from Mexico in search of the mythical ‘Seven Cities of Cibola’, only to find villages of mud and thatch in what is now the south-western United States. He sent out smaller parties, one of which explored the Grand Canyon. In 1540 another Spaniard, Hernado de Alarcón, ascended the Colorado River to its confluence with the Gila River in present-day Arizona. In 1610 the Frenchman Étienne Brûlé became the first European to journey beyond the St. Lawrence River into what is now Canada, ascending the Ottawa River and reaching Lake Nipissing and Georgian Bay in Lake Huron. In 1615–16 he sighted the western shore of Lake Ontario, descended the Niagara River and explored what are now parts of modern New York and Pennsylvania. From there he descended what is now the Susquehanna River to Chesapeake Bay, Later, between 1621 and 1623, he discovered Lake Superior as well. Other explorers, as well as fur-traders and missionaries, would continue to open up the Great Lakes region before penetrating ever further south. By 1682 the Missouri River had been discovered and the Mississippi River had been mapped along its entire length. In 1690–92 the Englishman Henry Kelsey became the first European to see the Canadian Prairies, and over the next century all the remainder of North America including much of Alaska and the islands of the northern Pacific would be opened up. At the time that the first British, French, and Spanish settlers began to arrive during the early sixteenth century, North America was still fairly pristine. Herds of bison (Bison bison) thundered across the prairies and flocks of passenger pigeons (Ectopistes migratorius) swept across the sky, almost covering it fromhorizon to horizon. Vast virgin forests, both coniferous and deciduous, stretched across the continent from the tundras of the north to the subtropical glades of Florida. Thousands of lakes, marshes, and rivers drained the country, channelling and accumulating the water on its long journey from the mighty mountains down to the oceans. Everywhere there was an abundance of wildlife. Gradually, however, this relative harmony would come to an end. In three and a half centuries North America has been the scene of a tremendous and rapid alteration of the natural environment, and consequently of the destruction of animal life. During the short period of the European settlement, a tragically long series of animals have become extinct. The white man swept over the continent, attacking almost everything: grass, trees, animals, and the aborigines who had lived for the most part in harmony with the environment for thousands of years. With their technological means, they destroyed more of the renewable natural resources than they built up. Despite all this, there yet remains much unspoiled country, a great diversity of natural habitats, and a wealth of animal life here. During the late twentieth century both the United States and Canada did much to preserve nature by means of legislation, protected areas, and education, largely repairing in a few decades what they had destroyed over the centuries. Sadly, this environmental leadership and sense of responsibility is now largely a thing of the past. North America is once more witnessing an almost unbelievable increase in the destructive exploitation of living nature, with the struggle between exploiters and conservationists having become more violent and bitter than ever.
In recent historical time (i.e. since ad 1500), the Nearctic Realm as a whole has lost at least 43 species/27 subspecies of vertebrates. Among the extinct forms, 4 species/13 subspecies are mammals, 11 species/8 subspecies are birds, 1 species is an amphibian, and 27 species/6 subspecies are freshwater fishes. Another 3 species/1 subspecies are possibly extinct, and 7 species are currently extinct in the wild.
In addition, there are 406 species/85 subspecies currently threatened with extinction (that is to say, either Critically Endangered, Endangered, or Vulnerable according to the IUCN Red List, as well as certain forms either listed as Data Deficient or Not Assessed but which are clearly at some risk of extinction). Of these, 42 species/35 subspecies are mammals, 35 species/18 subspecies are birds, 59 species/13 subspecies are reptiles, 75 species/3 subspecies are amphibians, and 195 species/16 subspecies are freshwater fishes.