The Patagonian Realm
The Patagonian Realm comprises much of southern and south-western South America along with the Galápagos Islands, Falkland Islands, Juan Fernández Islands, and a few smaller offshore islands. Biogeographically speaking it has obvious affinities to the Neotropical Realm, with which it has traditionally been included, but differs in a number of significant ways owing to its separation by the Andes Mountains. Notably dry for the most part, it ranges from tropical in the north to subpolar in the south. Indeed, southern South America lies nearer to Antarctica than does any other continent, and these areas are therefore often bitterly cold, with glaciers covering the mountains and mists and clouds often sweeping around them. But the microclimates are even more various, owing to differences in altitude and temperatures south of 40°S. latitude. Temperate deciduous forests, arid brushlands, deserts, steppes, and sub-Antarctic moors are the major vegetation types. As one moves south from Chile to the region south of the Strait of Magellan the vegetation changes from forests consisting of many trees covered with epiphytes and lianas to areas where the tree species are few, with half of the forests being composed of southern beeches (Nothofagus). The fauna diminishes in the same way. Large areas of Patagonia once consisted of rich temperate grasslands, but have declined considerably due to overgrazing of cattle. Here the vegetation has disappeared over large areas, erosion has set in, and dust fills the air.
Species and subspecies
The Pampas wolf (Dusicyon avus) is known from fossils collected in the Pampean and Patagonian areas of Argentina, southern Chile, Uruguay, and southern Brazil. Radiocarbon evidence indicates that it disappeared between 500 and 325 years ago, around the time of European colonization.
Darwin’s fox (Lycalopex fulvipes) is a rare species found patchily in the mountains of south-central coastal Chile (in particular Nahuelbuta National Park) and on Chiloé Island.
The guiña (Leopardus guigna), the smallest felid of the Americas, is divided into two subspecies. The southern guiña (L. g. guigna) is found in southern Chile and western Argentina. The northern guiña (L. g. tigrillo) occurs in central and northern Chile. Both are threatened by loss of habitat, human persecution, roadkill, and disease.
The guanaco (Lama guanicoe) is a type of camelid believed to be the wild ancestor of the domesticated llama (L. glama) mentioned above, which has been selectively bred as a pack animal. An inhabitant of the southern Andes as well as the lower-elevation pampas and even the Atacama Desert, it is found discontinuously in Peru, Bolivia, Chile, Argentina, and Paraguay. Like the vicuña it was severely reduced by hunting, and indeed by the mid-twentieth century was close to disappearing in several countries. It too has since recovered to the point where it is no longer considered threatened, thanks to increased protection. The vast majority live in Argentina, where the species has also been introduced to the Falkland Islands.
The South Andean deer (Hippocamelus bisulcus) is confined to the Andes of southern Chile and south-western Argentina, where it lives in a variety of habitats and elevations. Historically much more widespread, it has been seriously impacted by hunting and habitat destruction.
Yepes’ lesser long-nosed armadillo (Dasypus yepesi) is known only from a few localities in north-western Argentina (Jujuy and Salta provinces).
The pink fairy armadillo (Chlamyphorus truncatus), the smallest of all armadillo species, is found in the drier areas of central Argentina where it is threatened by loss of habitat and collection for use as pets.
Several small burrowing rodents of the genus Ctenomys are threatened by loss of habitat. The San Rafael tuco-tuco (C. pontifex) is known only from its original collection in 1918 from an imprecise locality in west-central Argentina (San Luis or Mendoza province). The robust tuco-tuco (C. tuconax) is found disjunctly within a small area of northwestern Argentina (Tucumán province). Thomas’ tuco-tuco (C. pontifex) is a poorly known species from a small area of central-western Argentina (Mendoza and possibly San Luis provinces). Rusconi’s tuco-tuco (C. australis) is confined to a few sand dune localities in central-eastern Argentina (Buenos Aires province). The Río Negro tuco-tuco (C. rionegrensis) is found patchily in the sand dunes of north-eastern Argentina (Entre Ríos province) and western Uruguay (Río Negro department). The Salta tuco-tuco (C. saltarius) is known only from a few localities in north-western Argentina (Salta province). Scaglia’s tuco-tuco (C. scagliai) is known only from a small area of north-western Argentina (Tucumán province). Azara’s tuco-tuco (C. azarae) is confined to a small area of central Argentina (La Pampa, Mendoza, and San Luis provinces). The social tuco-tuco (C. sociabilis) is confined to a small area of central-western Argentina (Neuquen province). The strong tuco-tuco (C. validus) is known only from a single locality in west-central Argentina (Mendoza province).
Bridge’s degu (Octodon bridgesi) is a type of rodent found in central Chile and central-western Argentina, where it is threatened by loss of habitat. It has been extirpated from many parts of its former range.
The colocolo opossum (Dromiciops gliroides) is a small, nocturnal marsupial confined to the temperate and subarctic forests of southern Chile (including the island of Chiloé) and adjacent south-western Argentina. It is potentially threatened by logging activities.
Tate’s fat-tailed mouse opossum (Thylamys tatei) is confined to a few localities in the coastal deserts and shrublands of western Peru (Ancash and Lima departments).
The blunt-eared bat (Tomopeas ravus) is confined to a few localities in coastal Peru, both lowland desert and mountainous areas. It is threatened by loss of its roosting sites.
The Atacama mouse-eared bat (Myotis atacamensis) is known from a few widely scattered localities in southern Peru and northern Chile.
The smoky bat (Amorphochilus schnablii) is found in coastal areas from Ecuador to northern Chile, where it is threatened by loss of habitat and collection for use in certain witchcraft rituals.
Several subspecies of greater rhea (Rhea americana), previously discussed, are threatened by hunting and habitat destruction. The intermediate greater rhea (R. a. intermedia) occurs in Uruguay and extreme south-eastern Brazil (Rio Grande do Sul). The noble greater rhea (R. a. nobilis) is confined to eastern Paraguay, east of the Paraguay River. The chaco greater rhea (R. a. araneipes) is found in Paraguay, Bolivia, and southern Brazil (Mato Grosso). The southern greater rhea (R. a. albescens) is found on the plains of central and southern Argentina.
The Andean condor (Vultur gryphus), the world’s largest flying bird, can still be found throughout much of western South America in the Andes as well as adjacent Pacific coasts. The species is everywhere rare, however, particularly in the north of its range, and heavily persecuted by humans by means of poisoning for its alleged attacks upon livestock. Reintroduction programmes using rescued and captive-bred individuals have been implemented in parts of Colombia, Chile, and Argentina.
The rufous-tailed hawk (Buteo ventralis) is a naturally rare species found widely in southern Chile and south-western Argentina. It is threatened by loss of habitat.
The Tucumán Amazon (Amazona tucumana) is a type of parrot known from a few localities in south-central Bolivia and north-western Argentina, where it is threatened by habitat destruction and capture for the pet trade.
The dot-winged crake (Laterallus spiloptera) is a type of rail found in south-eastern Brazil (Rio Grande do Sul), northern and eastern Argentina, and (at least historically) southern Uruguay. It is threatened by loss of its wetland and grassland habitat.
The yellow cardinal (Gubernatrix cristata) was historically widespread and common over a relatively wide area of southeastern Brazil (Rio Grande do Sul), northern and central Argentina, south-eastern Paraguay, and Uruguay. It has declined significantly, however, and indeed been extirpated from much of its former range due to habitat destruction and collection for the cage-bird trade.
The rufous flycatcher (Myiarchus semirufus) is a rare type of passerine bird confined to the deserts and steppes of coastal western and north-western Peru.
The strange-tailed tyrant (Alectrurus risora) is a type of flycatcher that was historically very widespread in the grasslands and marshes of central South America, but which has undergone a catastrophic decline due to habitat destruction. Now most likely extirpated from southern Brazil, it is largely confined to southern Paraguay and perhaps parts of northeastern Argentina and western Uruguay.
The Peruvian plantcutter (Phytotoma raimondii) is a type of passerine bird confined to scrub and dry forest areas in coastal north-western Peru, where it is highly threatened by habitat destruction.
The grey-headed antbird (Ampelornis griseiceps) is a rare species confined to a few small areas of south-western Ecuador (El Oro and Loja provinces) and north-western Peru (Tumbes, Piura, Lambayeque, and Cajamarca departments). It is threatened by loss of habitat.
The Patagonian tortoise (Chelonoidis chilensis) as currently recognized is found primarily in Argentina and adjacent areas of Bolivia and Paraguay, although it is suspected that more than one taxon may be involved. It is threatened mainly by loss of habitat.
The western leaf-toed gecko (Phyllodactylus lepidopygus) is confined to a small area of foothills and desert in central coastal Peru (Ancash, Ica, and Lima departments). The Atacama beaked toad (Rhinella atacamensis) is confined to coastal north-western Chile (Antofagasta, Atacama, Coquimbo, and Valparaíso regions), where it lives in both coastal desert and scrub areas. The red-spotted beaked toad (R. rubropunctata) is found patchily in south-central Chile and south-western Argentina. Both are threatened by loss of habitat.
Devincenz’s redbelly toad (Melanophryniscus devincenzii) is found disjunctly in north-eastern Argentina (Misiones province) and north-central Uruguay (Rivera, Tacuarembó, and Cerro Largo departments). It is threatened by loss of habitat and pollution.
Bullock’s false toad (Telmatobufo bullocki) is an aquatic species known only from a few localities within Nahuelbuta National Park in south-central coastal Chile.
Barrio’s frog (Insuetophrynus acarpicus) is confined to a few localities within the Pelada Range of south-central coastal Chile (Los Rios region).
The southern Darwin’s frog (Rhinoderma darwinii) is a biologically interesting mouth-brooding species still found across a relatively wide area of southern Chile and, marginally, south-western Argentina, but is threatened by habitat loss and, most likely, chytridiomycosis.
Mountains and Highlands
This section includes the central and southern Andes and the Chilean Coastal Cordillera as well as a few smaller, isolated ranges. Considerable differences in elevation and precipitation have created a great diversity of habitats, including montane temperate rainforests and subpolar forests, Mediterranean forest, grasslands, highland steppe, and arid shrublands.
Chinchillas (Chinchilla) are relatively large rodents endemic to the Patagonian Realm, where they live in colonies typically at high elevations. They are notable for having the densest fur of any terrestrial mammal, and as such have long been exploited for their valuable pelts. The animals were once extremely abundant and could be seen in the thousands during a single day. The Incas used chinchilla fur, but it was not until the pelts were introduced into Europe and the United States that the demand increased exponentially. Commercial hunting began in 1829 and grew steadily thereafter. By the twentieth century they were close to extinction, resulting in a ban on hunting being declared by international treaty (although this protection has never been effectively enforced). There are two species. The short-tailed chinchilla (C. chinchilla) was historically found in south-western Peru, south-western Bolivia, north-western Argentina, and northern Chile, but is today known for certain only from parts of Chile, Argentina, and perhaps marginally in Bolivia. The long-tailed chinchilla (C. lanigera) has been reduced to a small number of colonies in the coastal foothills of northern Chile. Both are common in ‘chinchilla farms’, although such captive populations are extensively interbred.
Hellmich’s tree iguana (Liolaemus hellmichi) is known only from a handful of specimens collected within Morro Moreno National Park in coastal northern Chile (Anfagasta region). Rabino’s tree iguana (L. rabinoi) is known only from an area of high-elevation desert in west-central Argentina (Mendoza province), where it was thought to be extinct until its rediscovery in 2009.
Vanzolini’s ground snake (Lygophis vanzolinii) is confined to the Sierras de Córdoba and Sierra San Luis in northcentral Argentina.
The Central and Southern Andes
The central and southern Andes, as here defined, extend roughly from the Andean Plateau of south-eastern Peru and south-western Bolivia south through Chile and western Argentina to the tip of Patagonia.
The vicuña (Vicugna vicugna) is one of the two wild South American camelids that live in the high alpine areas of the Andes, the other being the guanaco (Lama guanicoe), previously discussed. It is thought to be the wild ancestor of domesticated alpacas (V. pacos), which are raised for their extremely fine wool. Historically abundant, the animals had ample grazing land despite cultivation and competition from their domestic relatives, but when Europeans arrived with firearms their numbers were considerably reduced. In 1920 the Peruvian government banned the hunting, trading, or exporting of the species, and similar measures were put in place in Bolivia. In addition, in 1966 the former government established the Pampa Galeras Reserve to protect a herd of around 1000 vicuña, the largest such concentration in South America. Nevertheless, the illegal trade in wool continued unabated. Between 1950 and 1970 about 400,000 vicuñas were killed, after which only 5000–10,000 remained in Peru, 10,000 in Ecuador, 1000–1500 in Bolivia, and less than 100 in Chile and Argentina. Since then, the overall population has increased significantly to around 350,000, and the remaining herds are now considered safe within a system of protected areas guarded by game wardens.
The Central Andean deer or taruca (Hippocamelus antisensis) is a medium-sized, heavy-bodied species found in scattered, mostly isolated populations throughout the central and southern Andes of Peru, south-western Bolivia, extreme northeastern Chile, and north-western Argentina.
The Andean mountain cat (Leopardus jacobita) is a small species with a patchy distribution in the high Andes of Argentina, Bolivia, Peru, and Chile. Known only from photographs prior to 1998, it is thought to number less than 2500.
Knight’s tuco-tuco (Ctenomys knighti) is a type of burrowing rodent confined to a small area of montane grassland in north-western Argentina (Catamarca and La Rioja provinces).
Porter’s rock rat (Aconaemys porteri) is confined to a small area of south-central Chile (Araucanía, Los Ríos, and Los Lagos regions) and south-western Argentina (Neuquén and Río Negro provinces).
The Punta de Vacas chinchilla rat (Abrocoma vaccarum) is known only from a single locality in west-central Argentina (Mendoza province).
Edith’s leaf-eared mouse (Graomys edithae) is confined to two areas of montane grassland in north-western Argentina (Catamarca and La Rioja provinces).
The rufous-throated dipper (Cinclus schulzii) is a rare, semi-aquatic passerine bird found along streams and rivers in the southern Andes of southern Bolivia (Tarija and Chuquisaca departments) and north-western Argentina (Jujuy, Salta, Tucumán, and Catamarca provinces). It is threatened by habitat destruction and degradation.
The Tamarugo conebill (Conirostrum tamarugense) is a type of passerine bird largely restricted to two populations within the Pampa del Tamarugal National Reserve in northern Chile (Tarapacá region), from where it migrates north as far as southern Peru (Arequipa, Tacna, and Moquegua departments).
Baer’s mountain finch (Poospiza baeri) is known only from a few localities across a relatively wide area of the southern Andes in north-western Argentina, possibly extending into southern Bolivia. It is threatened by habitat destruction and degradation.
Several species of tree iguana (Liolaemus) endemic to the southern Andes are seriously threatened by habitat destruction. The O’Higgin’s tree iguana (L. curis) is confined to a small area of central Chile (Libertador Gral Bernardo O’Higgins region), where the total population now consists of only a few individuals. Montanez’s tree iguana (L. montanezi) is known only from two specimens collected from a single locality in north-western Argentina (San Juan province). The grey tree iguana (L. cinereus) is known only from four specimens collected from San Guillermo National Park in north-western Argentina (San Juan province). Duellman’s tree iguana (L. duellmani) is known only from four specimens collected from a single locality in central-western Argentina (Mendoza province). Herman Nunez’s tree iguana (L. hermannunezi) is known only from a single locality in southcentral Chile (Biobío region). Lorenz Müller’s tree iguana (L. lorenzmuelleri) is confined to a small area of north-central Chile (Coquimbo and Atacama regions). Paulina’s tree iguana (L. paulinae) is confined to a small area of northern Chile (Antofagasta region). The leopard tree iguana (L. leopardinus) is confined to a small area of central Chile (Metropolitana de Santiago region). The explorer’s tree iguana (L. exploratorum) is known only from museum material thought to have originated in what is now south-western Argentina (Santa Cruz province). The shoulder tree iguana (L. scapularis) is confined to a small area of north-western Argentina (Salta, Catamarca, and Tucumán provinces).
Rumboll’s beaked toad (Rhinella rumbolli) is known only from a small area of north-western Argentina (Jujuy and Salta provinces). Gallardo’s beaked toad (R. gallardoi) is confined to Calilegua National Park and a few nearby localities in northwestern Argentina (Jujuy province). Both are threatened by habitat destruction and introduced predatory fish.
Philippi’s false toad (Telmatobufo venustus) is a rare species known only from two small areas of south-central Chile (Maule and Biobío regions).
Three species of marsupial frog (Gathrotheca) endemic to the southern Andes are seriously threatened by loss of habitat, chytridiomycosis, and other factors. Christian’s marsupial frog (G. christiani) was historically known from to a few localities within the Callilegua and Porongal ranges of northwestern Argentina (Jujuy and Salta provinces). Not recorded in many years despite repeated surveys, it is most likely extinct. Baritú’s marsupial frog (G. chrysosticta) is known for certain only from a few areas of Yungas forest in north-western Argentina (Salta province). The graceful marsupial frog (G. gracilis) is confined to a few localities in north-western Argentina (Catamarca and Tucumán provinces).
The Las Bayas Patagonia frog (Atelognathus solitarius) and Nito’s Patagonia frog (A. nitoi) are each known only from a small area of south-western Argentina (Rio Negro province). The Zapala Patagonia frog (A. praebasalticus) is confined to a few localities in central-western Argentina (Neuquén province). The Laguna Blanca Patagonia frog (A. patagonicus) is a mainly aquatic species confined to the volcanic tablelands of west-central Argentina (Neuquén province), where it lives in scattered endorreic and isolated lakes and ponds. The Portezuelo Patagonia frog (A. salai) is confined to a small area of south-western Argentina (Santa Cruz province) and south-central Chile (Aysén region). All are threatened by habitat destruction and degradation, and in some areas by introduced predatory fish species and disease.
Several species of spiny-chest frog (Alsodes) endemic to the southern Andes are threatened by loss of habitat. The Malleco spiny-chest frog (A. vittatus) is known only from a single locality in south-central Chile (Biobío and/or Araucanía regions), where it has not been recorded since its original discovery in 1902 despite repeated searches. It is most likely extinct. The Pehuenche spiny-chest frog (A. pehuenche) is an aquatic species known only from a few streams within the Pehuenche Valley of west-central Argentina (Mendoza province) and adjacent south-central Chile (Maule region). The Tolhuaca spiny-chest frog (A. igneus) was long known only from Tolhuaca National Park in south-central Chile (Araucanía region), but has since been discovered in two other disjunct localities in Los Rios region. Lataste’s spiny-chest frog (A. montanus) and the La Parva spiny-chest frog (A. tumultuosus) are both confined to a few localities in central Chile (Metropolitana region). Hugo’s spiny-chest frog (A. hugoi) is known only from a few specimens collected from the Altos de Lircay National Reserve in south-central Chile (Maule region).
Several species of water frog (Telmatobius) are endemic to the central and southern Andes, where most are strongly associated with lakes, rivers, and other wetlands, while a few are entirely aquatic. All are seriously threatened by a range of factors including loss of habitat, pollution, water extraction, invasive fish species, and chytrid fungus. The Tafí Valley water frog (T. laticeps) is known only from the Tafí River Valley in north-western Argentina (Tucumán province). It has not been recorded in decades despite repeated surveys, and is most likely extinct. Ceis’ water frog (T. ceiorum) was historically known from a handful of localities in north-western Argentina (Catamarca and Tucumán provinces). It has not been recorded in decades despite repeated surveys, and may be extinct. The Arica water frog (T. pefauri) was long known only from a single specimen collected in extreme northern Chile (Arica y Pinacota region) in 1976. Long feared extinct, it may still exist in small numbers. The Rio Vilama water frog (T. vilamensis), Philipp’s water frog (T. philippii), Danko’s water frog (T. dankoi), and the Puquios water frog (T. fronteriensis) are each confined to a single locality in northern Chile (Antofagasta region), where they are seriously threatened by pollution and water extraction. The Tumbaya water frog (T. hypselocephalus) is known only from two localities in north-western Argentina (Jujuy province). The Zapahuira water frog (T. zapahuirensis) is known from two localities in northern Chile (Arica y Pinacota region). Pisano’s water frog (T. pisanoi) is confined to the Calchaquí Valley of north-western Argentina (Catamarca and Tucumán provinces). The flat-headed water frog (T. platycephalus) is known only from four localities in north-western Argentina (Jujuy province). Contreras’ water frog (T. contrerasi) is confined to a small area within the Gualcamayo Valley of central-western Argentina (San Juan province). The butterwort water frog (T. pinguiculus), Stephan’s water frog (T. stephani), and the Andalgala water frog (T. scrocchii) are each known only from a few localities in north-western Argentina (Catamarca province). Schreiter’s water frog (T. schreiteri) is known only from a few localities in north-western Argentina (La Rioja province). The pointy-headed water frog (T. oxycephalus) is known only from the Calilegua and Tilcara ranges of northwestern Argentina (Jujuy province), but may now be extirpated from the former. The Huayra water frog (T. huayra) is known for certain only from south-western Bolivia (Potosí department), but may also occur in north-western Argentina (Jujuy province). The Tarapacá water frog (T. chusmisensis) is confined to a few localities in northern Chile (Tarapacá region). The marbled water frog (T. marmoratus) remains relatively widespread within the highlands of western Bolivia, northern Chile, and southern Peru.
The Andean Plateau
The Andean Plateau (Altiplano – ‘high plains’ – in Spanish) is mainly located in south-western Bolivia, extending north into south-western Peru and south into northern Chile and northwestern Argentina. The area where the Andes are at their widest, and indeed the most extensive high plateau on Earth outside of Tibet, it is characterized by harsh, frigid deserts, salt flats, and alpine grasslands.
Gerlepp’s mouse (Galenomys garleppi) is known only from a few localities across the Andean Plateau, where it was last recorded in 1975.
Osgood’s leaf-eared mouse (Phyllotis osgoodi) is known only from a small area of northern Chile (Arica y Pinacota region).
The Rio Grande beaked toad (Rhinella gnustae) is known only from a single locality in north-western Argentina (Juyjuy province).
The Huayllamarca water frog (Telmatobius gigas) is known only from the canyon of the Huayllamarca River in western Bolivia (Oruro department). It is threatened by pollution and overcollection for use in ‘traditional medicine’.
The Atacama Plateau
The Atacama Plateau (Puna de Atacama in Spanish) is a high, arid plateau located in northern Chile (Antofagasta and Atacama regions) and north-western Argentina (Salta, Juyuy, and Catmarca provinces).
The Atacama water frog (Telmatobius atacamensis) is a wholly aquatic species confined to bog streams within a small area of the Atacama Plateau in north-western Argentina (Salta province).
The Aconquija Range
The Aconquija Range (Sierra del Aconquija in Spanish) is located in north-western Argentina (Tucumán province). It is the easternmost spur of the southern Andes.
Anita’s leaf-eared mouse (Phyllotis anitae) is known only from a single locality within the Aconquija Range.
The Aconquija tree iguana (Liolaemus griseus) is known only from a small area of the Aconquija Range.
The Ambato Range
The Ambato Range (Sierra de Ambato in Spanish) is located in north-western Argentina (Catamarca and La Rioja provinces).
Budin’s chinchilla rat (Abrocoma budini) appears to be confined to the Ambato Range.
The Fatima Range
The Fatima Range (Sierra de Fatima in Spanish) is located in north-western Argentina (La Rioja province).
The Fatima tree iguana (Liolaemus famatinae) is confined to the Fatima Range, where it is potentially threatened by mining operations.
The thorntail mountain lizard (Phymaturus mallimaccii) is confined to the Fatima Range, where it is seriously threatened by open-pit mining activities.
The Famatina Range
The Famatina Range (Sierra de Famatina in Spanish) is located in north-western Argentina (La Rioja province).
The Famatina chinchilla rat (Abrocoma famatina) is known only from the Famatina Range.
The Famatina tree iguana (Liolaemus dicktracyi) is confined to the Famatina Range, where it is potentially threatened by mining operations.
The Uspallata Range
The Uspallata Range (Sierra de Uspallata in Spanish) is located in central-western Argentina (Mendoza province).
The Uspallata chinchilla rat (Abrocoma uspallata) is known only from two localities within the Uspallata Range.
The Baguales Range
The Baguales Range (Sierra de los Baguales in Spanish) is located in south-western Argentina (Santa Cruz province) and southern Chile (Aysén region).
Wolffsohn’s viscacha (Lagidium wolffsohni) is a chinchillalike rodent confined to the Baguales Range.
The Chilean Coastal Cordillera
The Chilean Coastal Cordillera (Cordillera de la Costa in Spanish) runs from north to south along the Pacific coast of Chile parallel to the Andes.
Valeria’s forest lizard (Pristidactylus valeriae) and Alvaro’s forest lizard (P. alvaroi) are each known only from a few localities within the Chilean Coastal Cordillera, where they are threatened by habitat destruction.
The Cantillana Mountains
The Cantillana Mountains (Altos de Cantillana in Spanish) are located in central coastal Chile (Metropolitana region).
The Cantillana spiny-chest frog (Alsodes cantillanensis) is confined to a small area of the Cantillana Mountains, where it is threatened by loss of habitat.
The Nahuelbuta Range
The Nahuelbuta Range is located in south-central coastal Chile (Biobío and Araucanía regions).
The Cabreria spiny-chest frog (Alsodes barrioi) is confined to a single locality within the Nahelbuta Range, where it is threatened by loss of habitat.
The Pelada Range
The Pelada Range (Sierra de Fatima in Spanish) is located in south-central coastal Chile (Los Ríos region).
The Mirador spiny-chest frog (Alsodes valdiviensis) is known only a few localities within the Pelada Range.
The Córdoba Ranges
The Córdoba Ranges (Sierras de Córdoba in Spanish) are located in central Argentina (Córdoba and San Luis provinces).
Osvaldo Reig’s tuco-tuco (Ctenomys osvaldoreigi) is a type of burrowing rodent confined to a small area of highland grassland within Córdoba province. A fire in 2006 severely impacted the species, which continues to be threatened by sheep-herding activities.
The Córdoba escuerzo frog (Odontophrynus achalensis) is confined to a few localities in the Sierras de Córdoba, where it is threatened by loss of habitat.
The Somuncará Plateau
The Somuncurá Plateau (Meseta de Somuncurá in Spanish) is an isolated basaltic plateau located in east-central Argentina (Río Negro province).
The El Rincon four-eyed frog (Pleurodema somuncurense) is confined to geothermal springs and streams on the Somuncurá Plateau. It is threatened by introduced fish species, habitat degradation, water extraction, and chytrid infection.
The Laguna Raimunda Patagonia frog (Atelognathus reverberii) is found patchily on the shores of temporary lakes on the Somuncurá Plateau.
The naked characin (Gymnocharacinus bergii), so-named for its lack of scales, is a type of relict freshwater fish confined to a single stream on the Somuncurá Plateau. It is seriously threatened by habitat degradation and introduced rainbow trout.
Lowland Subtropical Dry Forests
Small areas of subtropical lowland dry forest are to be found in north-western Argentina (Jujuy province).
The red-bellied gracile mouse opossum (Cryptonanus ignitus) is known only from a single specimen collected in 1962 from an undefined locality in north-western Argentina (Jujuy province). Its habitat has since been completely destroyed, and the species is now certainly extinct, although it has more recently been synonymised with the Chacoan gracile opossum (C. chacoensis).
Lowland Moist Forests
Areas of lowland moist forest (Valdivian temperate rainforest and Magellanic subpolar forest) are to be found in central and southern Chile and southern Argentina.
The olive spiny-chest frog (Alsodes verrucosus) is confined to two disjunct localities in south-central Chile (Araucanía, Los Ríos, and Los Lagos regions).
Lowland Valdivian Temperate Rainforest
Lower-elevation Valdivian temperate rainforests occupy a narrow band between the Pacific Ocean and the southern Andes in central and southern Chile and south-western Argentina. Dominated by southern beech (Nothofagus), they are characterized by their high humidity and dense understories of bamboos and ferns.
Pearson’s long-clawed mouse (Geoxus annectens) is known only from a few localities in south-central Chile (Araucanía, Los Ríos, and Los Lagos regions).
The northern Darwin’s frog (Rhinoderma rufum) historically occurred in south-central Chile (Valparaíso, Maule, and Biobío regions), where it was last recorded in 1981. It is possibly extinct, a victim of habitat loss and, most likely, chytridiomycosis.
Vanzolini’s spiny-chest frog (Alsodes vanzolinii) and Nora’s spiny-chest frog (A. norae) are each known only from a few localities in south-central coastal Chile.
Fitzroy’s wood frog (Batrachyla fitzroya) is known only from Isla Grande within Lake Menéndez in Los Alerces National Park, south-western Argentina (Chubut province).
Miguel’s ground frog (Eupsophus migueli) is confined to a small area of coastal Valdivian rainforest in southern Chile (Los Ríos and Araucanía regions).
Lowland Magellanic Subpolar Forests
The world’s southernmost forests, Magellanic subpolar forests are found in southern Chile (Aysén and Magallanes regions) and south-western Argentina (Santa Cruz and Tierra del Fuego provinces), west and south of the Andes.
The Kaweshkar spiny-chest frog (Alsodes kaweshkari) is known only from two specimens, the first collected from Wellington Island off the coast of south-western Chile and the other from the adjacent mainland in what is now Bernardo O’Higgins National Park. It was last recorded in 1998, and subsequent expeditions have failed to find it.
The Gran Chaco
The Gran Chaco is an extremely hot, semi-arid lowland dry forest and savanna region of the La Plata River drainage located west of the Pantanal and east of the Andes in southeastern Bolivia, western and southern Paraguay, northern Argentina, and, marginally, south-western Brazil (Mato Grosso and Mato Grosso do Sul).
The Chacoan peccary (Catagonus wagneri) is a pig-like hoofed mammal found in fragmented areas of the dry Chaco of western Paraguay, south-eastern Brazil, and northern Argentina. Originally described from pre-Hispanic and subfossil remains, it was first discovered alive in 1975. Rare and declining, it nevertheless continues to be hunted.
The greater fairy armadillo (Calyptophractus retusus) is found patchily in central and south-eastern Bolivia, western Paraguay, and extreme northern Argentina. While present in some protected areas, it is elsewhere killed on sight by the Guarani people in the traditional belief that it is an omen of death, or the spirit of a dead baby.
The southern three-banded armadillo (Tolypeutes matacus) is found in south-western Brazil (Mato Grosso and Mato Grosso do Sul), northern Argentina, south-eastern Bolivia, and western Paraguay. It is threatened by habitat destruction, hunting, and collection for use as pets.
Several small burrowing rodents of the genus Ctenomys, endemic to the Gran Chaco, are threatened by loss of habitat and persecution as agricultural pests. The lined tuco-tuco (C. dorsalis) is known only from a single specimen, now lost, collected from north-western Paraguay in 1900. Bonetto’s tuco-tuco (C. bonettoi) is confined to a small area of northeastern Argentina (Chaco province). The Pilar tuco-tuco (C. pilarensis) is confined to a few localities in south-eastern Paraguay (Ñeembucú and Misíones departments). The furtive tuco-tuco (C. occultus) and the mottled tuco-tuco (C. latro) are both confined to a small area of north-western Argentina (Tucumán province).
The fossorial giant rat (Gyldenstolpia fronto) is known only from one living specimen and some fossil material collected from a single locality in northern Argentina (Chaco province) during the nineteenth century. It is most likely extinct.
The burrowing chinchilla mouse (Euneomys fossor) is known only from its original collection during the late nineteenth century from an undefined locality in north-western Argentina (Salta province).
The Chaco side-necked turtle (Acanthochelys pallidipectoris) is a small freshwater turtle found in north-western Argentina, western Paraguay, and possibly south-eastern Bolivia, where it is threatened by habitat destruction and collection for the international pet trade.
The Chaco marked gecko (Homonota taragui) is known only from a single locality in north-eastern Argentina (Corrientes province), where it inhabits a unique basaltic formation consisting of three isolated rock ‘islands’. It is seriously threatened by quarrying activities.
The Bolivian burrowing snake (Apostolepis dorbignyi) is known only from two specimens collected during the early nineteenth century from southern Bolivia (Tarija department).
The pampas, as here defined, are essentially a sea of subtropical and temperate grasslands located throughout Uruguay as well as parts of north-eastern and east-central Argentina and southernmost Brazil (Rio Grande do Sul). Geographically they consist mainly of immense subtropical plains without either trees or hills, although in some parts these give way to palm savanna, gallery forests along rivers, and enclaves of submontane forest. Many kinds of grasses grow here in tussocks, and several of them are green throughout the year, but compared with the overwhelming animal richness of the African grassland the pampas are poor in wildlife. There are several characteristic species, but few of them live in herds. Peculiar to the pampas are its many species of rather large rodents. Among the most fertile areas of South America from an agricultural point of view, decades of intensive cultivation have caused much of the tall pampas grass to disappear and with it the habitats of some wild animals. Several species have been reduced to only a fraction of their former populations.
The southern Pampas deer (Ozotoceros bezoarticus celer) is known only from a few isolated localities in central Argentina, where it is threatened by habitat destruction and hunting.
Roig’s tuco-tuco (Ctenomys roigi) is a type of burrowing rodent confined to a small area of riverside sand dunes in north-eastern Argentina (Corrientes province). Pundt’s tucotuco (C. pundti) is confined to a small area of central Argentina (Córdoba and San Luis provinces). Both are seriously threatened by loss of habitat.
José’s hocicudo (Oxymycterus josei) is a type of rodent found patchily in southern Uruguay (Soriano, Colonia, San José, Canelones, and Maldonado departments), where it is threatened by loss of habitat.
The Pampas meadowlark (Leistes defilippii) was historically widespread and common in east-central Argentina and Uruguay, with additional rare records from southern Brazil (Rio Grande do Sul). The species has undergone a massive decline since 1900 due to loss of habitat, which unfortunately continues, and is now confined to four disjunct areas of central and north-eastern Uruguay and central-eastern Argentina (Buenos Aires and La Pampa provinces).
The Tandilia tree iguana (Liolaemus tandiliensis) inhabits lower-elevation rocky areas within grasslands in the Tandilia Range of east-central Argentina (Buenos Aires province). It is threatened by loss of habitat.
Amaral’s snake (Calamodontophis paucidens) is known only from four localities in south-eastern Brazil and Uruguay.
Langone’s redbelly toad (Melanophryniscus langonei) is known only from two disjunct localities in northern Uruguay (Rivera department), where it is seriously threatened by loss of habitat.
The red-spotted Argentina frog (Argenteohyla siemersi) is divided into two subspecies, both of which are threatened by loss of habitat. Siemers’ red-spotted Argentina frog (A. s. siemersi) is found disjunctly in central-eastern Argentina (Entre Ríos and Buenos Aires provinces) and southern Uruguay (San José and Rocha departments). Pedersen’s redspotted Argentina frog (A. s. pederseni) is confined to a small area of north-eastern Argentina (Corrientes province).
Lowland Deserts and Semi-deserts
The Patagonian Realm is quite arid, with a wide range of habitats including Argentine espinal, Argentine monte, steppe, and both cold and hot deserts.
Berg’s tuco-tuco (Ctenomys bergi) is a type of burrowing rodent confined to a small area of sand dunes in north-western Argentina (Córdoba province), where it is threatened by loss of habitat.
The Bajo de Añelo tree iguana (Liolaemus cuyumhue) is known only from a single small sand dune system in east-central Argentina (Neuquén province). It is seriously threatened by oil and gas exploration. Moreno’s tree iguana (L. morenoi) is known only from a small area of sand dunes in west-central Argentina (Neuquén province), where it is seriously threatened by habitat destruction.
The Ingeniero Jacobacci liolaemid (Phymaturus desuetus) is a type of iguanid lizard known only from a single specimen collected in south-central Argentina (Río Negro province). Manuela’s liolaemid (P. manuelae) is known only from a single basaltic plateau in south-central Argentina (Río Negro province).
The Sechura Desert
The Sechura Desert (Desierto de Sechura in Spanish; also known as the Nazca Desert) is located along most of northern and central coastal Peru, extending inland to the foothills of the Andes.
Zuniga’s dark rice rat (Melanomys zunigae) is known only from a small area of Andean foothills in central-western Peru (Lima department), where it has not been recorded since the mid-twentieth century despite extensive surveys. Its habitat has now been almost entirely destroyed, and the species is most likely extinct.
The Rimac Valley whorltail iguana (Stenocercus modestus) is confined to the Rimac Valley in coastal south-central Peru (Lima department).
The Cerro Illescas leaf-toed gecko (Phyllodactylus clinatus) is known only from a few specimens collected from a small area of coastal north-western Peru (Piura department). The Lima leaf-toed gecko (P. sentosus) is confined to a few archaeological sites in central-western coastal Peru (Lima department).
The dark blind snake (Epictia melanurus) is a small, fossorial species known only from its original collection in northwestern Peru (La Libertad department).
The Atacama Desert
The Atacama Desert (Desierto de Atacama in Spanish) is a plateau covering a 1000-km strip of land on the Pacific coast of northern Chile and southern Peru, west of the Andes. It is the driest non-polar desert in the world.
The Chilean woodstar (Eulidia yarrellii) is a rare type of hummingbird that appears to breed regularly only within two or three desert river valleys in extreme northern Chile (Arica y Parinacota region). Vagrants have been found in the Antofagasta region as well as in southern Peru, although there are no recent records from the latter country. The species is seriously threatened by loss of habitat, agricultural pesticides, and hybridization with the Peruvian sheartail (Thaumastura cora).
Manuel’s tree iguana (Liolaemus manueli) is known only from two localities. The erroneous tree iguana (L. erroneus) is known only from a single specimen collected from an undefined locality.
The Tarapacá Pacific iguana (Microlophus tarapacensis) is known only from a small area of northern Chile (Arica y Parinacota and Tarapacá regions).
Argentine Salt Flats
A number of scrubby, low-elevation salt flats and pans are located across isolated areas of north-central and northwestern Argentina.
The delicate salt flat mouse (Salinomys delicatus) is confined to a few isolated populations in north-western Argentina (Catamarca, La Rioja, San Juan, Mendoza, and San Luis provinces).
The Pipanaco Salt Pans
The Pipanaco Salt Pans (Salar de Pipanaco in Spanish) are located in north-western Argentina (Catamarca province).
The golden viscacha rat (Tympanoctomys aureus) is a burrowing species confined to the Pipanaco Salt Pans, where it is seriously threatened by conversion of its habitat for olive plantations.
The Great Salt Flats
The Great Salt Flats (Salinas Grandes in Spanish) are located in north-central and north-western Argentina (Córdoba, Catamarca, La Rioja, and Santiago del Estero provinces).
The Chalchalero viscacha rat (Tympanoctomys loschalchalerosorum) is known only from two specimens collected in north-western Argentina (La Rioja province).
The Patagonian Desert, also known as Patagonian steppe, is one of the largest deserts in the world. It is located primarily in southern Argentina (including Tierra del Fuego and the Falkland Islands, the latter of which are discussed separately), extending marginally into southern Chile and bounded by the Andes to the west and the Atlantic Ocean to the east.
Two burrowing rodents of the genus Ctenomys are endemic to the Patagonian Desert. The silky tuco-tuco (C. sericeus) is known only from a single locality in southern Argentina (Santa Cruz province). Colburn’s tuco-tuco (C. colburni) is known only from a few localities in southern Argentina (Santa Cruz and Río Negro provinces).
Kirchner’s viscacha rat (Tympanoctomys kirchnerorum) is known only from a small area of south-central Argentina (Chubut province).
The Patagonian chinchilla mouse (Euneomys chinchilloides) is confined to southern Argentina (Tierra del Fuego and neighbouring islands) and southern Chile (Magallanes region), where it is threatened by the overgrazing of its habitat by sheep.
Lakes, Rivers, and Marshes
The Patagonian Realm is notably dry and lacking in major lakes and rivers.
The giant otter (Pteronura brasiliensis), previously discussed in greater detail elsewhere in this volume, has been much reduced in the southern parts of its former range. It is now extinct or nearly so in Uruguay and Argentina, while in Paraguay it has been reduced to a single, small population. The southern river otter (Lontra provocax) occurs in Chile and Argentina in both freshwater and marine environments. Heavily hunted for their pelts, which are used in making clothing, they are also threatened by loss and degradation of their habitat.
The Andean flamingo (Phoenicoparrus andinus) occurs, during the summer months, on the high Andean plateaus of Peru, Chile, Bolivia, and Argentina where it breeds in colonies on the shores of various salt lakes, from where it migrates in winter to lower elevation wetlands. The species has undergone a considerable decline in recent decades due to hunting, egg collection, pollution, and loss of habitat.
The Titicaca grebe (Rollandia microptera) is a flightless aquatic species restricted to the Altiplano of Peru and Bolivia. It is known to occur from lakes Arapa and Umayo in southeastern Peru, through Lake Titicaca into adjacent Bolivia and along the Desaguadero River to lakes Uru-uru and Poopó. Temporary populations are found on smaller adjacent lakes in years when Lake Titicaca floods. In 2003 the total population was estimated at around 2500.
The hooded grebe (Podiceps gallardoi) breeds only in a few basaltic lakes in south-western Argentina, with the only known wintering grounds being the Coyle, Gallegos, and Chico river estuaries on the Atlantic coast. In 1997 the total world population was estimated at between 3000 and 5000, with half of these living on the Meseta de Strobel. Populations have since declined drastically, however, and today it is thought that only 1000–1200 remain.
The horned coot (Fulica cornuta) is limited to a few small, high-altitude Andean lakes in south-western Bolivia, northern Chile, and north-western Argentina. While still occasionally seen in fairly large numbers the overall population is believed to be small and prone to considerable fluctuations.
The austral rail (Rallus antarcticus) was long known only from three historical records, all prior to 1959, until its rediscovery in 1998. It is now known to occur in a few disjunct Patagonian wetland areas in southern Argentina and southern Chile, where it may be somewhat migratory.
The helmeted water toad (Calyptocephalella gayi) is confined to permanent ponds and reservoirs in central and southern Chile.
Hall’s water frog (Telmatobius halli) was long known only from a few specimens collected in 1935 from a high-elevation hot spring in northern Chile (Antofagasta region). Many searches were conducted over the years but no new specimens were found until 2020, when the species was rediscovered in a tiny hot spring oasis within the Atacama Desert. The Tinogasta water frog (T. hauthali) is confined to the Aguas Calientes spring and a small stretch of the Tamberias River in north-western Argentina (Catamarca province).
The Chilean perch (Percichthys melanops) is confined to a few pre-Andean streams in central Chile.
Irwin’s bass (Percilia irwini) is confined to the Malleco and Biobío river drainages of south-central Chile (Araucanía and Biobío regions).
The Los Alerces galaxias (Galaxias globiceps) is known only from a single locality in south-central Chile (Los Lagos region).
The Córdoba tetra (Astyanax cordovae) is confined to the Primero and Segundo rivers in north-central Argentina (Córdoba province).
The grey pearlfish (Austrolebias cinereus) is known only from a single temporary pond within the lower Uruguay River drainage, where it is seriously threatened by loss of habitat.
Lake Titicaca (Lago Titicaca in Spanish) is a large, deep lake located in the high Andes on the border between south-eastern Peru (Puno department) and western Bolivia (La Paz department). By volume of water it is the largest lake in South America, and with a surface elevation of 3812 m is the highest navigable lake in the world. Some two dozen rivers empty into it but only one carries water out, the remainder (about 95 per cent) simply evaporating in the hot sun and strong winds. Since the beginning of this century Lake Titicaca has experienced constantly receding water levels, a drop caused by shortened rainy seasons and the melting of glaciers feeding the tributaries of the lake.
The Titicaca water frog (Telmatobius culeus) is a very large, entirely aquatic species confined to Lake Titicaca and associated rivers. Formerly common, it has declined drastically in recent years due to overcollection for human consumption, pollution, and tadpole predation by introduced trout.
Lake Titicaca was historically home to around two dozen endemic pupfish species of the genus Orestias, many of which have been seriously impacted by competition with, and predation by, introduced fish species as well as by pollution. Cuvier’s orestias (O. cuvieri) appears to have become extinct sometime prior to 1962. Parenti’s orestias (O. ctenolepis), Silustan’s orestias (O. silustani), Pentland’s orestias (O. pentlandii), and the olive orestias (O. olivaceus) are all confined to Lake Titicaca.
Stuebel’s naked suckermouth catfish (Astroblepus stuebeli) is known only from the Lake Titicaca basin, where it has not been reported since 1916.
Miscellaneous Lakes, Rivers, and Marshes
Lake Chungará (Lago Chungara in Spanish) is located high in the Andes of far northern Chile (Arica y Parinacota region).
The Chungará orestias (Orestias chungarensis) and Chungará pencil catfish (Trichomycterus chungarensis) are both confined to Lake Chungará.
The Lauca River (Río Lauca in Spanish) originates in the Andean Plateau of northern Chile and flows west before eventually emptying into Coipasa Lake in Bolivia.
The Lauca orestias (Orestias parinacotensis) is confined to a single locality within the Lauca River.
Coasts and Satellite Islands
This section includes all of the coastal regions extending from northern Peru to south-eastern Brazil along with various island groups.
The South American fur seal (Arctocephalus australis) was nearly exterminated during the nineteenth century by hunters, but has since recovered. The nominate form (A. a. australis) is, however, confined to the Falkland Islands. The Juan Fernández fur seal (A. philippii) is a notably small, near-endemic species that once occurred within the Juan Fernández Islands in almost unbelievable numbers, as well as on the Desventuradas Islands. According to the buccaneer William Dampier, there was ‘not a bay or rock that one can get ashore on that is not full of them’. In 1792 one ship took 38,000 skins, and in 1798 another harvested 100,000 seals. Only nine years later seal hunting on Juan Fernández was scarcely worthwhile. It has been calculated that two or three million fur seals were killed on the island by 1824. In 1891 the population was estimated at just 300–400. A single seal was killed on Más a Tierra in 1917, after which the species was presumed to be extinct. There were no further records of it until 1965, when small groups perhaps numbering around 200 in total were sighted on Alejandro Selkirk and Robinson Crusoe islands. The species quickly recovered from just 750 individuals in 1969 to over 32,000 by 2005, living and breeding on Alejandro Selkirk, Robinson Crusoe, and Santa Clara islands. Today, the Juan Fernández fur seal is no longer considered to be threatened.
The marine otter (Lontra felina) is one of the smallest otter species and the world’s smallest marine mammal. Rare and little-known, it inhabits the southern Pacific coast of South America from northern Peru to the southern tip of Chile. At one time heavily hunted for its fur, it remains absent from many parts of its former range.
The Humboldt penguin (Spheniscus humboldti) lives year round along the Pacific coast of western South America from northern Peru to southern Chile, where it nests in scattered colonies. It is threatened by El Niño events, which result in reduced fish supply, as well as fisheries by-catch, predation by introduced species, and human disturbance.
The southern rockhopper penguin (Eudyptes chrysocome) is divided into two subspecies. The nominate form (E. c. chrysocome) breeds in colonies along the southern tip of South America from where they disperse widely at sea during other times. Hugely abundant during the first half of the twentieth century, it has declined considerably in number due to loss of habitat and climate change.
De Filippi’s petrel (Pterodroma defilippiana) breeds only in the Juan Fernández and Desventuradas islands off the coast of Chile. It is threatened by feral cat, rat, and coati predation on its eggs and young, which is believed to have caused its extirpation from Robinson Crusoe Island.
The ringed storm petrel (Hydrobates hornbyi) and Markham’s storm petrel (H. markhami) both range widely across the eastern Pacific and remain fairly common there, but are nevertheless vulnerable to loss of habitat within their breeding colonies in the coastal areas of north-western South America. The disorienting effects of light pollution have also emerged as a major problem.
Garnot’s diving petrel (Pelecanoides garnotii) remains widespread along the central-western coast of South America from northern Peru to south-central Chile, where historically it numbered in the millions. Pressures resulting from guano extraction (which destroys nests, eggs, and chicks), along with direct hunting by guano harvesters and predation from introduced foxes and cats on the offshore islands where the species breeds, have resulted in a serious decline. While many breeding colonies are located within nominally protected areas, some guano extraction continues.
The pink-footed shearwater (Ardenna creatopus) is a type of seabird that ranges widely across the eastern Pacific as far north as Alaska, but nests primarily on a few small islands off the coast of Chile (i.e. the Juan Fernández Islands and Mocha Island). It is threatened by introduced predators and illegal harvesting within its breeding colonies as well as by plastics pollution and fisheries by-catch.
The chiffío tern (Sternula lorata) occurs along the central-western coast of South America from northern Ecuador to northern Chile. A ground-nesting species, it is threatened by loss of habitat and human disturbance.
The white-headed steamer duck (Tachyeres leucocephalus) is a flightless species from the Patagonian coast of south-eastern Argentina, where it is particularly vulnerable to oil spills.
The striated caracara (Phalcoboenus australis) is a scavenging bird of prey confined to isolated shores, rookeries, and coastal islets at the extreme tip of southern Argentina and Chile as well as on the Falkland Islands. The species had been much reduced in number by sheep farmers, who shot it for its occasional attacks on young or injured livestock, but it is now legally protected.
The Peruvian martin (Progne murphyi) is a rare species from coastal Peru and extreme northern coastal Chile (Arica y Parinacota region), including a few offshore islands.
The many-spotted tree iguana (Liolaemus multimaculatus) is confined to dunes along the central-eastern coast of Argentina (Buenos Aires and extreme north-eastern Río Negro province).
The narrow leaf-toed gecko (Phyllodactylus angustidigitus) is confined to a small area of beaches and offshore islands in coastal south-eastern Peru (Ica department).
The Cabo Polonio whiptail lizard (Contomastix charrua) was known only from Cabo Polonio in coastal south-eastern Uruguay, where it was last recorded in 1977. It is now thought to be extinct, a victim of habitat destruction and introduced predators.
Orejas Miranda’s redbelly toad (Melanophryniscus orejasmirandai) is confined to a single locality in coastal southern Uruguay (Maldonado department). The Montevideo redbelly toad (M. montevidensis) is confined to coastal south-eastern Uruguay (Montevideo, Canelones, Maldonado, and Rocha departments) and adjacent south-eastern Brazil (Rio Grande do Sul). Both are threatened by loss of habitat.
The Galápagos Islands
The Galápagos Islands (Archipiélago de Colón or Las Islas Galápagos in Spanish) are an archipelago of volcanic islands located on either side of the equator about 900 km west of Ecuador. They were first discovered by the Spaniards in 1535, and consist of 5 larger and 10 smaller islands along with a considerable number of islets and skerries. Several rise to altitudes of 600–1500 m, and the climate is dry, particularly at lower elevations. On the higher islands such as Isabela (or Albemarle, the largest of the group), Santa Cruz (Indefatigable), Fernandina (Narborough), Santiago or San Salvador (James), and San Cristóbal (Chatham), there is a lowland arid belt of cacti and mesquite thickets. Above this, dwarf-leafed acacias cover some sections, while others have a jungle-like association of larger trees. Higher slopes may be covered by forests, sometimes of an almost luxuriant type rich in mosses and ferns. Further up is a belt of shrubs dominated by Miconia mixed with fern. The summits are in general grassy. Prominent almost everywhere is the evidence of volcanic origin. Bare basalt rocks, crater holes and fissures, thousands of lava blocks, often grotesquely shaped, are surrounded by undecomposed lava that plants have not yet been able to colonize. To the aridity of this landscape is added the burning equatorial sun. At present only Isabela and Santiago show ongoing volcanic activity.
The Galápagos Islands are notable for the remarkable adaptive radiation shown by their plants and animals. Both the flora and fauna display a high degree of endemism, as would be expected in such an isolated tropical archipelago. It continues to be the best living laboratory of evolution of the world. It is therefore a pity that so much of it has been destroyed. During the seventeenth century buccaneers used the islands as a hideout, and in the nineteenth century came the whalers. The latter loaded their ships with living tortoises as a way of storing fresh meat. The capture of Galápagos tortoises almost became an industry, not only for food but also for oil extracted from the fat. One estimate is that about 15,000 tortoises were taken between 1811 and 1844, and another is that American whalers captured at least 13,000 tortoises between 1831 and 1867. It is believed that since the discovery of the islands as many as 10 million tortoises were slaughtered. Introduced species very nearly destroyed the native vegetation and preyed directly upon the defenceless native mammals, birds, and reptiles and their eggs. These islands were famously studied by Charles Darwin during the second voyage of the HMS Beagle in 1835. His observations and collections contributed to the inception of the theory of evolution by means of natural selection. Already in his voyage around South America he had been impressed by the biological wealth of the tropics and the adaptation of animals to conditions in the Andes, and was already convinced that evolution had taken place but did not understand how it worked. The Galápagos gave him the key to the enigma, because there he found many examples of small evolutionary changes in species due to adaptation from island to island. Happily, all introduced animals have now been removed from the islands except for rats, which have so far only been eradicated from the smaller islands of Rábida and Pinzón. Galápagos National Park (Parque Nacional Galápagos in Spanish) was established in 1959 and began operations in 1968. It covers 97 per cent of the land area of the islands, with the remaining 3 per cent set aside for the inhabited areas of Santa Cruz, San Cristóbal, Baltra, Floreana, and Isabela.
The Galápagos fur seal (Arctocephalus galapagoensis) was seriously depleted through centuries of slaughter by whalers and sealers. In 1816 one ship harvested 8000 seals, and 5000 were killed by another ship in 1823. But by 1882 the total catch was down to 800 and in 1897–99 one schooner could collect only 224 skins. At that time the last strongholds of the Galápagos fur seal were on Fernandina, Isabela, and Wolf (Wenman) islands. There were no further reports of the species until one was collected in 1906. When William Beebe worked on the Galápagos Islands in 1923 he found the fur seal to be very rare, although Ruth Rose reported a colony of 60–70 animals from the Guy Fawkes Islands, north-west of Santa Cruz. In 1933–35 the Galápagos fur seal only occurred on Genovesa, but in the 1950s a large colony was found on Santiago. In 1961 it was found on Fernandina, Isabela, Pinta, Santiago, Rábida, Marchena, Santa Cruz, Baltra, North Seymour, and Genovesa islands; and in 1962, 60 fur seals were observed on Santiago and later about 500 on Isabela. By 1970 several colonies were well established, an impressive recovery from a very precarious state. However, between 1977 and 2001 the population crashed once more before again rebounding somewhat.
The Galápagos sea lion (Zalophus wollebaeki) is found on all the major islands and on many smaller islands and rocks. An additional colony was established in 1986 at Isla de la Plata, just off the coast of mainland Ecuador, and vagrants are occasionally reported along the Ecuadorian coast as far north as Gorgona Island. The population underwent a decline by as much as 60–65 per cent between 1978 and 2001. Since then it seems to have stabilized, but the species remains vulnerable to El Niño events and infectious disease.
The Galápagos penguin (Spheniscus mendiculus) is the most northerly species of penguin, and highly dependent upon the cool, nutrient-rich waters of the western Galápagos. Once fairly common, hunting and the collection of its eggs for food reduced its numbers sharply during the nineteenth century. Today it breeds mainly on Isabela and Fernandina, with some nesting occurring as well on Floreana, Santiago, and several smaller islets. The total population is small but fluctuates dramatically, from as low as 700 in 1983 to as many as 10,000 in 1971. In 2013 it was estimated at between 1800 and 4700.
The Galápagos flightless cormorant (Phalacrocorax harrisi) has a severely restricted distribution, being found only around the coast of Fernandina and parts of Isabela. The population suffered a sharp decline from about 4000 in 1962 to around 1000 just three years later, mainly due to hunting and egg collection by locals. By the early 1970s it had increased slightly to 1600 and remained more or less stable until the 1980s. During the 1983 El Niño event it crashed to just 400 but recovered quickly. There were over 1000 estimated in 1986, 900 in 1999, 1400 in 2006, and over 2000 by 2013.
The Galápagos dark-rumped petrel (Pterodroma phaeopygia) breeds on Santa Cruz, Floreana, Santiago, San Cristóbal, Isabela, and possibly others. The birds forage around the islands but also disperse at other times as far as French Polynesia, the Philippines, and Central and South America. In 2008 the total population was estimated at between 10,000 and 20,000, but is considered threatened by introduced predators and agricultural expansion on its nesting islands.
The lava gull (Larus fuliginosus) is found sporadically throughout the Galápagos Archipelago, with the main concentrations on Santa Cruz, San Cristóbal, and Isabela. In 2012 the total population was estimated at less than 250.
The Galápagos hawk (Buteo galapagoensis) was once widespread throughout the islands and was still common in 1924. Its extraordinary tameness made it particularly vulnerable to hunters, however. By the early 1960s it had already been exterminated on several islands, with a total population of not more than 200. Today perhaps 400–500 birds live on the islands of Santiago, Española, Isabela, Fernandina, Pinta, Marchena, Pinzón, and Santa Fé.
The Galápagos crake (Laterallus spilonota) is a type of rail that still occurs on a number of islands including Pinta, Fernandina, Isabela, Santiago, Santa Cruz, Floreana, and possibly San Cristóbal, generally in highland areas near freshwater pools. However, given its weak flying ability, it is likely vulnerable to introduced predators such as rats, cats, dogs, and pigs. Darwin’s vermilion flycatcher (Pyrocephalus nanus) is still found throughout the Galápagos with the exception of San Cristóbal, but has possibly been extirpated on Floreana and Santa Fé and is in serious decline on Santa Cruz due to loss of habitat, disease, and pollution.
The mangrove finch (Geospiza heliobates) is historically known from mangrove patches on the eastern coast of Fernandina and eastern, southern, and western Isabela. The last record from Fernandina, however, was in 1971 and the species appears to have disappeared from that island. In 2013 the total population was estimated at between 50 and 100. The woodpecker finch (G. pallida) is found on Santa Cruz, San Cristóbal, Santiago, Isabela, Fernandina, and Pinzón. Both are threatened by loss of habitat and introduced species.
The large tree finch (Camarhynchus psittacula) still has breeding populations on Isabela, Santa Cruz, Santa Fé, Fernandina, Santiago, Marchena, Pinta, and Rábida, but has declined on many of these islands as well as having been extirpated from Pinzón and, most likely, Floreana.
The Galápagos martin (Progne modesta) is found throughout the Galápagos islands, but is everywhere uncommon. The total population is thought to number 600–1000.
The giant land tortoises (Chelonoidis) inhabiting the Galápagos Islands are the largest in the world. Long considered to be a single species with a varying number of subspecies (based primarily upon shell size and shape), recent research has led to the general acceptance of at least 12 extant species and two or three more which are now extinct. When first discovered during the seventeenth century they were incredibly numerous throughout the major islands of the archipelago, estimated to number over 250,000. Darwin himself observed them in large numbers on San Cristóbal Island. Overexploitation for their meat and oil, however, combined with habitat clearance and the introduction of non-native species resulted in an all-time low by the 1970s of around 3000. Each species will be dealt with individually below.
Three species of large land iguana (Conolophus) inhabit the Galápagos, where they were at one time killed in large numbers for their fleshy tails, which were used as food by sailors. Later, introduced goats became their primary threat owing to the fact that destroyed the plants that the lizards used both for food as well as for cover from predators such as the Galápagos hawk (Buteo galapagoensis). They have since recovered their numbers but remain vulnerable. The most widespread species, the Galápagos land iguana (C. subcristatus), inhabits the dry lowlands of Fernandina, Isabela, Santa Cruz, North Seymour, Baltra, and South Plaza, the latter a small islet off Santa Cruz. The other two species are discussed below.
The Galápagos marine iguana (Amblyrhynchus cristatus) lives mainly on the rocky coasts and intertidal zones of the Galápagos Archipelago and has the unique ability among modern lizards to forage in the sea, where it can reach depths of up to 20 m. Although relatively large numbers remain and the animals can be locally abundant they are considered threatened by El Niños, introduced predators, and the possibility of oil spills. Several subspecies are recognized. The Santiago marine iguana (A. c. wikelskii) is found on Santiago Island and smaller nearby islands such as Rábida. Other subspecies are discussed below.
Isabela Island (Isla Isabela in Spanish; also known as Albemarle Island) is the largest of the Galápagos Islands. The island’s seahorse shape is the product of the merging of six large volcanoes into a single land mass.
Five distinct species of giant tortoise, all isolated from one another, are known to live on Isabela. This remarkable number of taxa occurring on a single island is unique in the Galápagos and is due to its unusual volcanic formation. The Volcán Wolf giant tortoise (Chelonoidis becki) is largely confined to the northern, ,western and south-western slopes of Wolf Volcano, with a small number also living on an isolated plateau inside the crater itself. It is believed to have derived from a colonization event originating from the island of Santiago, as opposed to the other four giant tortoise populations to the south, which are believed to have been descended from a separate colonization from the island of Santa Cruz. Its population is estimated at around 1200. The Volcán Alcedo giant tortoise (C. vandenburghi) is found in central Isabela on the caldera and southern slopes of Alcedo Volcano, where it is by far the most numerous species. The Volcán Sierra Negra giant tortoise (C. guntheri) is confined to the eastern, western, and southwestern slopes of the Sierra Negra Volcano. The total population is under 700. The Iguana Cove giant tortoise (C. vicina) is found on Cerro Azul Volcano, where its range may overlap with that of the Sierra Negra giant tortoise. The total population is around 2500. Finally, the Volcán Darwin giant tortoise (C. microphyes) is confined to the southern and western slopes of Darwin Volcano, where the total population is around 800.
The Volcán Wolf pink land iguana (Conolophus marthae) is a recently described species confined to the northern slopes of Wolf Volcano, where the total population is very small.
The Isabela marine iguana (Amblyrhynchus cristatus cristatus) is found on both Isabela and Fernandina islands.
Santa Cruz Island (Isla Santa Cruz in Spanish; also known as Indefatigable Island) is the second largest of the Galápagos Islands. The Charles Darwin Research Station is located on the island, where it conducts both research as well as captivebreeding programmes for threatened species.
The Galapágos giant rat (Megaoryzomys curioi) is known only from a single subfossil cave deposit, but which nevertheless indicates that the species recently occurred on Santa Cruz. It seems to have inhabited shrub forests, and was likely eradicated by invasive species.
Two species of rice rat (Nesoryzomys) formerly inhabited Santa Cruz, but are now believed to be extinct. Darwin’s rice rat (N. darwini) was last recorded in 1930, while the Santa Cruz rice rat (N. indefessus), which is known from Santa Cruz and Baltra islands, was last collected in 1934. Both are thought to have been the victims of black rats (Rattus rattus) and other introduced species.
Two species of giant tortoise (Chelonoidis) are found naturally on Santa Cruz. Donfausto’s giant tortoise (C. donfaustoi) is confined to the eastern slopes of the island. Porter’s giant tortoise (C. porteri) is found in the south-west. A small population of introduced Pinzón giant tortoises (C. duncanensis) also occurs in the island’s north-west.
The Santa Cruz marine iguana (Amblyrhynchus cristatus hassi) is confined to Santa Cruz and smaller adjacent islands such as Baltra.
The Galápagos cusk-eel (Ogilbia galapagosensis) is a fresh and brackish water species known only from four caves on Santa Cruz.
Fernandina Island (Isla Fernandina in Spanish; also known as Narborough Island) is the youngest and most westerly of the Galápagos Islands. It is also the most ecologically pristine. In 2005 a new, very eruptive process began here, when an ash and water vapour cloud rose to a height of 7 km and lava flows descended the slopes of the volcano on their way to the sea.
Two species of rice rat, Nesoryzomys fernandinae and N. narboroughi, are confined to Fernandina, where they appear to be relatively common.
The Fernandina giant tortoise (Chelonoidis phantastica) is, at time of writing, the world’s rarest chelonian. Long known only from a single adult male found (and killed) in 1906; apart from the discovery of putative tortoise droppings in 1964 there had been no other signs of the species until 2019, when a second live specimen was collected from a different island and genetically confirmed as being the same species.
Santiago Island (Isla Santiago or Isla San Salvador in Spanish; also known as San Salvador or James Island) consists of two overlapping volcanoes. Introduced goats reduced the coastal lowlands to deserts during the nineteenth century. The Santiago rice rat (Nesoryzomys swarthi) was long thought to be extinct until rediscovered in 1997. Today it is known from a few areas on Santiago.
The Santiago giant tortoise (Chelonoidis darwini) is restricted to the west-central part of the island, where the total population is estimated at around 1200.
San Cristóbal Island (Isla San Cristóbal in Spanish; also known at Chatham Island) is the easternmost of the Galápagos Islands.
The Galápagos rice rat (Aegialomys galapagoensis) is divided into two subspecies. The San Cristóbal rice rat (A. g. galapagoensis) was known to Charles Darwin when he visited the island in 1835. It was then abundant, but in 1898–99 another expedition searched for it in vain. Subfossil remains were found in lava tubes in 1984.
The San Cristóbal vermillion flycatcher (Pyrocephalus dubius) has not been reported since the 1980s, and is now considered extinct. Formerly found throughout the island, it likely fell victim to introduced predators, disease, or both.
The San Cristóbal mockingbird (Mimus melanotis) still numbers around 8000, but is considered highly vulnerable.
The San Cristóbal giant tortoise (Chelonoidis chathamensis) was long thought to be extinct, but was rediscovered in small numbers during the 1960s. Fencing of nests and feral dog eradication during the 1970s helped the species to recover, and today the population is estimated at around 6700, all living in the north-east of the island.
Two subspecies of marine iguana (Amblyrhynchus cristatus) are endemic to San Cristóbal island. Merten’s marine iguana (A. c. mertensi) is found on the south-western side, while the Godzilla marine iguana (A. c. godzilla) occurs in the north-east. Both are considered threatened.
The San Cristóbal leaf-toed gecko (Phyllodactylus leei) is confined to San Cristóbal Island.
Floreana Island (Isla Floreana in Spanish; also known as Santa Maria or Charles Island) is a small island in the southern Galápagos. Owing to its relatively flat surface and supply of fresh water, it was a favourite stop for whalers and other ships. In 1820, during one such visit, the island was set alight as a prank by a sailor. It was the height of the dry season, and the fire reduced the island to a blackened wasteland for years to come. The fire is thought to have possibly contributed to the extinction of some endemic species never to be described. During the early twentieth century it served as a penal colony.
The Floreana mockingbird (Mimus trifasciatus) was exterminated on the island whose name it bears sometime between 1868 and 1880, but survives in very low numbers on two small islets (Champion and Gardner-by-Floreana).
The medium tree finch (Geospiza pauper) is confined to Floreana, where its already small population is decreasing owing to the effects of an introduced ectoparasite and other factors.
The Floreana giant tortoise (Chelonoidis nigra) was historically abundant but heavily exploited. Darwin observed the species in 1835, and noted that it comprised the main food item on the island. Just three years later a visiting ship could find no tortoises, and in 1846 another traveller declared them extinct.
Baur’s leaf-toed gecko (Phyllodactylus baurii) is endemic to Floreana Island and associated islets. Only one specimen has been collected this century (in 2008), and the species is thought to be vulnerable to introduced cats.
Española Island (Isla Española in Spanish; also known as Hood Island) is the oldest of the Galápagos Islands, as well as the southernmost. Due to its remoteness, it has evolved a number of endemic species.
The waved albatross (Phoebastria irrorata), the world’s only equatorial albatross, breeds primarily along the southern coast of Española in the Galápagos islands, where the steep cliffs serve as the perfect runway for the birds. There are also perhaps a few nesting pairs on La Plata Island, off the coast of Ecuador.
The Española mockingbird (Mimus macdonaldi) is confined to Española and the small adjacent islet of Gardner-by- Española.
The Española cactus finch (Geospiza conirostris) is confined to Española, where the total population is under 1000.
The Española giant tortoise (Chelonoidis hoodensis) was very heavily exploited by whalers during the nineteenth century. The population appears to have collapsed around 1850. Thirteen adults (2 males and 11 females) were found in the early 1970s and transferred to the Charles Darwin Research Station on Santa Cruz in a captive-breeding effort. A third male was subsequently identified at the San Diego Zoo and joined the others. The effort proved a success and, eventually, large numbers were released back into the wild. Today the wild population is around 1000, with many others in captivity.
The Española marine iguana (Amblyrhynchus cristatus venustissimus) is found on Española Island and adjacent, tiny Gardner-by-Española Island, as well as on Floreana Island.
Pinta (Isla Pinta in Spanish; also known as Abingdon Island) is a small, elongated island and the northernmost of the Galápagos.
The Pinta giant tortoise (Chelonoidis abingdoni) formerly occurred on the southern slopes of Pinta Island, where it was severely depleted by whalers and fishermen. The introduction of goats on Pinta in 1958 resulted in a massive destruction of its vegetation. The species was long thought to be extinct until a single living male was discovered in 1972. Named ‘Lonesome George’, he was taken to the Charles Darwin Research Station on Santa Cruz, where it was hoped that a mate might be found for him, if only with a closely related species. These efforts were unsuccessful, and this individual died in 2012. However, a hybrid found on Isabela Island in 2007 suggests that there may yet be a surviving Pinta giant tortoise there.
The Pinta marine iguana (Amblyrhynchus cristatus sielmanni) is confined to Pinta Island.
Marchena Island (Isla Marchena in Spanish; also known as Bindloe Island) is located about 70 km west of Tower Island.
The Marchena marine iguana (Amblyrhynchus cristatus hayampi) is confined to the island.
Genovesa Island (Isla Genovesa in Spanish; also known as Tower Island) is a small, horseshoe-shaped island in the northern Galápagos.
The Genovesa ground finch (Geospiza acutirostris) and the Genovesa cactus finch (G. propinqua) are both considered vulnerable due to their highly restricted range.
The Genovesa marine iguana (Amblyrhynchus cristatus nanus) is confined to the island.
Pinzón Island (Isla Pinzón in Spanish; also known as Duncan Island) is a tiny island marking the geographic centre of the Galápagos Islands.
The Pinzón giant tortoise (Chelonoidis duncanensis) had been relatively undisturbed by whalers, although large numbers had been removed by other expeditions in the late nineteenth and early twentieth centuries. After the introduction of rats to the island no natural breeding succeeded, and the population declined until the species was considered to be extinct in the wild (although a few very old individuals continued to survive). After 1965, however, eggs had been transported to the Charles Darwin Research Station on Santa Cruz for hatching and rearing. Rats were finally eradicated on Pinzón between 2012 and 2014, and today, some 530 tortoises live once again on the south-western part of the island.
Rábida Island (Isla Rábida in Spanish; also known as Jervis Island) was heavily affected by introduced species. In 1971 the National Park service successfully eradicated goats from the island.
The Rábida giant tortoise (Chelonoidis wallacei) is a disputed species known only from some tracks observed in 1897 and a single specimen (now lost) collected in 1906.
Santa Fé Island (Isla Santa Fé in Spanish; also known as Barrington Island) is a small island lying at the centre of the archipelago.
The Santa Fé rice rat (Aegialomys galapagoensis bauri) is confined to Santa Fé, where it is threatened by introduced species.
The Santa Fé land iguana (Conolophus pallidus) is confined to Santa Fé, where the total population is estimated at about 300.
The Santa Fé marine iguana (Amblyrhynchus cristatus trillmichi) is confined to Santa Fé.
Darwin, Wolf, and Roco Redonda Islands
Darwin Island (Isla Darwin in Spanish; also known as Culpepper Island) and the smaller Wolf Island (Isla Wolf; also known as Wenman Island) and Roca Redonda are located on the north-western edge of the Galápagos Archipelago.
The vampire ground finch (Geospiza septentrionalis), an interesting species which feeds in part from blood pecked from other birds, is endemic to Wolf and Darwin islands.
Jeffreys’ marine iguana (Amblyrhynchus cristatus jeffreysi) is found on Darwin Island and the smaller satellite islands of Wolf Island and Roca Redonda.
The Juan Fernández Islands
The Juan Fernández Islands (Archipiélago Juan Fernández in Spanish) are a sparsely inhabited island group located about 670 km west of Chile in the south-eastern Pacific.
The Juan Fernández silverside (Odontesthes gracilis) is a little-known type of freshwater and marine fish endemic to the Juan Fernández Islands.
Alejandro Selkirk Island
Alejandro Selkirk Island (Isla Alejandro Selkirk in Spanish; previously known as Isla Más Afuera – literally ‘furthest out’) is the largest and most westerly of the Juan Fernández Islands. It is located 180 km west of Robinson Crusoe Island.
Salvin’s petrel (Pterodroma externa) and Stejneger’s petrel (P. longirostris) both breed only on Alejandro Selkirk Island, from where they disperse at other times across the Pacific. While numerous they both appear to be declining due to invasive dogs, cats, rats, mice, and goats.
The Alejandro Selkirk creeper (Aphrastura masafuerae), one of the rarest of all South American birds, is confined to the northern and eastern coasts of Alejandro Selkirk Island, where the total population is estimated at between 140 and 150. It is threatened by introduced goats, rats, and cats.
The Juan Fernández firecrown hummingbird (Sephanoides fernandensis) is divided into two subspecies. The Más Afuera firecrown hummingbird (S. f. leyboldi) was confined to Alejandro Selkirk Island, where it was last reported in 1908. It is presumed extinct, a victim of feral goats and other introduced animals.
Robinson Crusoe Island
Robinson Crusoe Island (Isla Róbinson Crusoe in Spanish; previously known as Más a Tierra – literally ‘closer to land’) is located 670 km off the coast of Chile.
The Más a Tierra firecrown hummingbird (Sephanoides fernandensis fernandensis) is confined to Robinson Crusoe Island.
Mocha Island (Isla Mocha in Spanish) is a small, mountainous island located 40 km off the coast of central Chile. Its Valdivian forest vegetation is now largely confined to a few square kilometres of its highest elevation.
The Mocha degu (Octodon pacificus) is an endemic rodent that was last recorded in 1959 before its rediscovery in December 2015.
The Mocha ground frog (Eupsophus insularis) is another seriously threatened species that was last collected in 2003.
The Falkland Islands
The Falkland Islands (Islas Malvinas in Spanish) lie on the continental shelf about 480 km east of the southern Patagonian coast, on the boundary between the sub-Antarctic oceanic and tundra climate zones. The archipelago consists of two rather mountainous main islands (East and West Falkland) and some 776 smaller ones. Constant gales prevent the growth of trees and larger shrubs on these islands and tussock grass covers all the plains and hills, giving the landscape an impression of desolation and solitude. An abundance of sheep as well as cattle and horses have greatly affected the grass and dwarf shrub vegetation. Ungrazed, tussock grass grows to around 2 m in height, but on the main island, East Falkland, it rises only a few centimetres or has almost vanished from large areas. Apparently, early humans never reached the Falkland Islands, so when the gauchos arrived they found virgin country. All but the very smallest of the islands have since been colonized and not only sheep but also cattle, horses, pigs, hares, rabbits, rats, and mice are found almost everywhere. Virtually the entire land area is used as pasture for sheep. Introduced species include reindeer, hares, rabbits, Patagonian foxes, brown rats, and cats. The detrimental impact several of these have caused to native flora and fauna has led authorities to attempt to contain, remove or exterminate invasive species. The extent of human impact on the Falklands is unclear as there are few long-term data on habitat change, but unrestricted grazing by livestock – particularly sheep, which by 1899 numbered more than 750,000 – has certainly caused a tremendous change of vegetation. The coastal belt of tussock grass has almost disappeared or has been thinned out to such an extent that, besides the resulting erosion, about half of the breeding bird species of the Falkland Islands have lost their habitats. The farmers blame two species of geese – the upland goose (Chloephaga picta) and the ruddy-headed goose (C. rubidiceps) – for the overgrazing and have attempted to get rid of the birds by poisoning, in spite of the obvious fact that the birds had been there for millennia prior to the arrival of man and sheep. The Falklands are still home to five different penguin species and a few of the largest albatross colonies on the planet, although the latter no longer breed on the main islands.
The Falklands wolf or warrah (Dusicyon australis) was the only native terrestrial mammal on these islands. At the end of the eighteenth century it was very numerous and quite tame. Gauchos attracted them by holding out a piece of meat and stabbing the animal when it came within reach. Charles Darwin, who visited the Falkland Islands in 1833, foresaw the extinction of the species owing to its lack of fear. By 1863 it was exterminated in the eastern parts of East Falkland. Largescale sheep-raising led to poisoning campaigns, but it was the fur trade that finally doomed it. The last individual was killed on West Falkland Island in 1876.
The Chonos Archipelago
The Chonos Archipelago (Archipiélago de Chonos in Spanish) is a series of low, mountainous, elongated islands located in coastal southern Chile.
The Inchy spiny-chest frog (Alsodes monticola) is known only from its original collection during the 1840s from Inchy Island.
Anthropogenic effects on the flora and fauna
According to the archaeological and fossil evidence, modern humans may have first arrived within the Patagonian Realm from Central America by about 13,000 bc, from where they gradually spread south as far as Tierra del Fuego. Stone tool evidence indicates that the latter had reached these southernmost parts by around 10,000 years ago. These early migrants supported themselves through slash-and-burn agriculture and hunting – in the process wiping out several species of giant ground sloth as well as car-sized giant armadillos and many other spectacular creatures shortly before the arrival of Europeans. The Incas of Peru had meanwhile developed a system of irrigation agriculture; thus valleys, plains, slopes, and wildlife were already being modified there in pre-Columbian days. By the time the Spaniards reached South America, for instance, the llama (Lama glama) and the alpaca (Vicugna pacos) had already long been domesticated and had lost certain characteristics. Other species were already in retreat. Early European exploration of the Patagonian Realm was dominated at first by the Portuguese and Spanish. In 1511–12 the Portuguese explorers João de Lisboa and Estevao de Frois visited the River Plate estuary in what is now Uruguay, from where they travelled south along the coast of present-day Argentina. In 1520, while attempting to circumnavigate the globe, Ferdinand Magellan explored the Atlantic coast of Patagonia and discovered the southern passage from the Atlantic to the Pacific now named after him (the Strait of Magellan). He would be followed soon after by Spanish conquistadors in search of gold, who easily conquered the indigenous peoples of what are now Chile and Peru. Around 1524 the Portuguese explorer Aleixo Garcia travelled westward from what is now Santa Catarina state in south-western Brazil, across the Paraná River (where he perhaps sighted Iguazu Falls), to the Paraguay River near the site of present-day Asunción, Paraguay. He then crossed the Gran Chaco to the Andes and the Inca frontier somewhere in modern Bolivia. All of the southernmost part of the South American continent along with the islands towards Antarctica became a Spanish colony in 1529. In 1535 Rodrigo de Isla became the first European to traverse the great Patagonian plain, while Fray Tomás de Berlanga explored the Galápagos Islands. In 1535–37 Diego de Almagro led an expedition to what is now western Peru to the shore of Lake Titicaca, then through the altiplano from where he took a coastal route back through the Atacama Desert. In 1592 the English navigator John Davis discovered the Falkland Islands, and in 1616 the Dutch explorers Jacob Le Maire and Willem Schouten discovered Cape Horn. After the discovery of the route around the latter the Spanish Crown lost interest in southern Patagonia until the eighteenth century, when new coastal settlements were established, although it maintained its claim of sovereignty to the area.
In recent historical time (i.e. since ad 1500), the Patagonian Realm has lost at least 16 species/1 subspecies of vertebrates. Among the extinct forms 8 species are mammals, 1 species/1 subspecies are birds, 3 species are reptiles, 3 species are amphibians, and 1 species is a freshwater fish. Another 5 species are possibly extinct.
In addition, there are 254 species/18 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, 67 species/3 subspecies are mammals, 54 species/4 subspecies are birds, 57 species/10 subspecies are reptiles, 61 species/1 subspecies are amphibians, and 15 species are freshwater fishes.