The Neotropical Realm
The Neotropical Realm includes most of Central and South America with the exception of the Caribbean Islands, the drier areas to the west of the Andes in north-western South America along with the central and southern Andes, and the subtropical, temperate, and subarctic zones of the south-east, all of which are dealt with separately on this website. is here divided into two zoogeographic regions (the Mesoamerican and Amazonian). This area is mostly tropical, extending slightly into the subtropical zone in the south-east. It has more rainforests, mainly in the Amazon basin, than any other continent, as well as drier forests and savannas. Among the mountain chains of the world the Andes are second only to the Himalayas in height. They form a western border for the whole of South America and a formidable barrier separating the Pacific Ocean and its shores from the interior of the continent. The Andean highlands are almost a world unto themselves. Great valleys, plains, slopes, and cordilleras divide this enormous chain, transversely as well as from north to south. The range of microclimates as well as of vegetation is very wide, not only because of the extreme variations in altitude from the ocean shore to the highest peaks, but also because of the range in latitudes from the Caribbean shore in the north to southern Peru and Bolivia in the south.
South America was originally part of the supercontinent of Gondwana, which included Africa, Australia, India, New Zealand, and Antarctica, and thus shares many plant and animal lineages with these continents. After the break-up of the latter about 110 million years ago, South America was separated from Africa and became an ‘island continent’, drifting slowly north and west. Owing to this long isolation it evolved an astonishingly rich mammalian fauna, with an extraordinary number of unique hoofed animal species. Eventually, about two to three million years ago, it was joined with North America by the formation of the Isthmus of Panama, which allowed a biotic exchange between the two continents known as the Great American Interchange. South American species such as oppossums and armadillos moved into North America, while camelids, for instance, moved south. The long-term effect of this process was to be the extinction or displacement of many South American species, mostly due to competition with northern ones.
Species and subspecies
The jaguar (Panthera onca), the largest cat native in the Americas and the third largest in the world, remains widespread in both central and northern South America but has almost completely disappeared in many areas due to loss of habitat and human persecution. Its present range extends from the south-western United States (where the species has been almost completely extirpated since the early twentieth century) south to Paraguay and northern Argentina.
The spectacled or Andean bear (Tremarctos ornatus) is the only representative of the bear family in South America and the continent’s largest carnivore. The species is still found patchily throughout the Andes of western Venezuela, western and central Colombia, central Ecuador, western and central Peru, western and central Bolivia, and north-western Argentina. Before its populations began to be fragmented by human pressure it had a reputation for being highly adaptable, ranging from the lower foothills to the snow line and in a variety of habitats, although today it is most typical of humid montane forest patches. In addition to habitat destruction poaching has also become a major threat.
The white-lipped peccary (Tayassu pecari) is a pig-like species found throughout much of Central and northern South America from south-eastern Mexico to southern Brazil and northern Argentina, where it lives in a wide range of habitats. It is everywhere threatened by loss of habitat and intense hunting pressure.
The giant anteater (Myrmecophaga tridactyla) is a large, terrestrial insectivore notable for its elongated snout. The species remains widespread within a variety of habitats in both Central and South America but has been extirpated in many areas due to hunting and habitat destruction, particularly in Central America (where it is one of the most threatened of all mammals) and in the southern part of its range.
Gorgas’ rice rat (Oryzomys gorgasi) is a semi-aquatic species known only from a few coastal wetland localities in northern Colombia and north-western Venezuela. It appears to have formerly occurred on Curaçao as well, but is now extirpated there.
The Agami heron (Agamia agami) is found widely in swamp forest areas throughout Central and South America, but is everywhere threatened by habitat destruction and hunting.
The banded ground cuckoo (Neomorphus radiolosus) occurs in south-western Colombia and north-western Ecuador, where it is threatened by loss of habitat.
The Colombian crake (Neocrex colombiana) is a type of rail divided into two subspecies. The nominate form (N. c. colombiana) is considered rare throughout its range, with scattered records extending from northern Colombia to western Ecuador. Ripley’s Colombian crake (N. c. ripleyi) is known only from three specimens collected in central and eastern Panama and north-western Colombia.
The little woodstar (Chaetocercus bombus) is a type of hummingbird found patchily in western Ecuador and northestern Peru, where it appears to make seasonal migrations between different habitats and elevations. It is threatened by deforestation.
The red-footed tortoise (Chelonoidis carbonarius) is found in suitable habitat across a wide area from southern Panama to Bolivia, Paraguay, and possibly northern Argentina, but is everywhere threatened by collection for food and the international pet trade.
The Magdalena river turtle (Podocnemis lewyana) is confined to the Sinú and Magdalena river drainages of northwestern Colombia.
The green poison dart frog (Andinobates viridis) was historically found on the Pacific slopes of the Cordillera Occidental in south-western Colombia (Cauca and Valle del Cauca departments). The species underwent a drastic decline, most likely due to chytridiomycosis, and has not been recorded since 2005 despite surveys. It is possibly extinct.
Lynch’s robber frog (Pristimantis crenunguis) is confined to a small area of north-western Ecuador (Pichincha, Esmeraldas, and Santo Domingo de Los Tsáchilas provinces).
The Muisca anostomid (Leporinus muyscorum) is a type of freshwater fish found within the Magdalena, Atrato, Truandó, Ranchería, and Sinú river drainages of north-western Colombia. It is threatened by overfishing.
Anthropogenic effects on the flora and fauna
In recent historical time (i.e. since ad 1500), the Neotropical Realm as a whole has lost at least 47 species/2 subspecies of vertebrates. Among the extinct forms 5 species/1 subspecies are mammals, 7 species/1 subspecies are birds, 3 species are reptiles, 25 species are amphibians, and 6 species are freshwater fishes. Another 100 species are possibly extinct, and 9 species are currently extinct in the wild.
In addition, there are 2791 species/101 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, 319 species/21 subspecies are mammals, 405 species/67 subspecies are birds, 402 species/12 subspecies are reptiles, 1347 species/1 subspecies are amphibians, and 318 species are freshwater fishes.