South American yellow-footed tortoise  (Geochelone denticulata)

Classified as Vulnerable (VU) on the IUCN Red List (1) and listed on Appendix II of CITES (3).

The largest tortoise on the mainland of South America, this tortoise is named after the large yellow or orange scales that cover the front of each forelimb (2). The elongated carapace, or upper shell, of the South American yellow-footed tortoise is brown, with yellowish or orange tones in the centre of each scute. The well developed shell on the underside of the tortoise, the plastron, is yellowish-brown, with darker colouring at the edges of the scutes. Thin, leathery, yellow to orange scales cover the head of the tortoise, and it has a slightly hooked upper jaw (2). Males of this species are generally larger than females, and can also be distinguished by their longer, thicker tails, more elongated carapace, and concave plastron (2). It is thought that the more elongated carapace of the male is better suited to moving through the dense understorey of the forest, while the shell of females is adapted to store eggs (4).

The South American yellow-footed tortoise ranges from south-eastern Venezuela, through Guyana, Suriname and French Guiana to Brazil. It is found throughout the Amazon basin, to eastern Colombia and Ecuador, north-eastern Peru and north-eastern Bolivia. It is also found on the islands of Trinidad and Tobago (1) (2).

An inhabitant of tropical evergreen and deciduous rainforests (2), the South American yellow-footed tortoise is often found in the vicinity of water (5), and is said to do well in humid conditions (6).

The South American yellow-footed tortoise is an omnivorous reptile, which feeds on a variety of leaves, vines, roots, bark, fruits and flowers, as well as fungi, insects and snails (7), and the rotting flesh of dead animals such as deer, armadillos, porcupines and snakes (4). Bizarrely, soil, sand and pebbles are also consumed; these abrasive objects presumably assist the digestion of foods, as this tortoise has a tendency to swallow foods whole (7).

Fruits are a major part of the diet throughout the year, but particularly during the wet season (7). Male South American yellow-footed tortoises become more active during periods of fruit abundance, and may even synchronise their mating periods with this season, when the fruits provide them with more energy to move around in search of females (4). During the mating period, the male sniffs the cloacal region of the female, before proceeding to push, ram and bite her, before commencing mating. It is thought that several clutches of eggs are laid each year, each containing up to twenty eggs, but averaging four to eight. The elongated, brittle-shelled eggs are incubated for four to five months (2).

Threatened by hunting throughout its range (8), the South American yellow-footed tortoise is now considered to be vulnerable to extinction (1). Although it is generally not the primary target of hunters, Amazonian Indians always capture these slow-moving tortoises when out hunting for other animals (5) (9). The tortoise is kept alive until it is eaten or sold. While the meat of the tortoise is the primary reason for capture, it is also valued as a pet (5). The slow growth rate, late sexual maturity and low reproductive rate of the South American yellow-footed tortoise makes this species highly susceptible to the impacts of harvesting, and it is now suspected that population numbers are dwindling (5).

The South American yellow-footed tortoise is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that any international trade in this species should be carefully monitored (3). Captive breeding of this species does occur, as it has been reported that many for sale in the pet trade are captive bred (6), which may act to reduce pressure on wild populations. Despite its vast area, South America has relatively few tortoises (6), making the survival of this species even more poignant.

View information on this species at the UNEP World Conservation Monitoring Centre.