Angulate tortoise  (Chersina angulata)

Listed on Appendix II of CITES (1).

A distinguishing feature of the angulate tortoise is its greatly enlarged ‘gular scute’, the frontmost part of its lower shell, under the head, which is used by the male as a weapon to ram and overturn other males when fighting for dominance (3) (4) (5). A small to medium-sized (3) and rather colourful tortoise (6), the angulate tortoise has an elongated, domed carapace (upper shell), which is yellowish brown to olive in colour. Wide dark borders and dark centres mark the scutes on the top of the carapace, and dark triangles decorate the seams of the scutes around its lower edge. The plastron, or lower shell, is yellow to reddish, with a wide black mark down the centre. The head is usually dark, often with yellow on top, the jaws are weakly serrated, and the upper jaw is hooked. The limbs are yellowish or brown and the toes bear strong claws (4). Male angulate tortoises are distinguished from females by being larger, and having a longer gular scute, longer tail, and concave plastron (3) (4) (6).

The angulate tortoise is endemic to South Africa and southwestern Namibia. It is particularly abundant in parts of the Cape Floristic Region, and occurs at elevations of up to 900 metres or more (4) (7) (8). The species has also been introduced to Dassen Island, off the coast of South Africa (9), and further north at Swakopmund and Walvis Bay in Namibia (10).

The angulate tortoise inhabits a wide range of habitats, including Fynbos, Succulent Karoo, Nama Karoo, and Albany Thicket (2) (3) (4).

The angulate tortoise feeds on a variety of angiosperms (flowering plants), as well as mosses, mushrooms, insects, snail shells and animal faeces (11). Activity patterns depend largely on temperature: on cool or wet days and in winter, the angulate tortoise is most active during the middle of the day, while in spring and summer it is less active during this hottest part of the day (12). Mating is most common between September and April. The male may pursue and bite at the legs and tail of the female during courtship (3) (4), as well as engaging in combat with rival males (3) (4) (5). When the time comes to nest, the female digs a hole, up to ten centimetres deep, into which usually only a single, oval-shaped egg is laid (3) (4) (13). Each female may potentially lay up to six times a year (13). The egg hatches after 4 to 14 months (4) (8), the new hatchling having a flattened shell a mere 4 centimetres long (3) (4). Reproductive maturity is not reached until about ten years of age (5).

The Cape Floristic Region is seriously threatened by a range of human activities which have greatly reduced the habitat of the angulate tortoise. Many areas have been extensively cultivated, forcing the angulate tortoise to survive in marginal areas of habitat which are often small and fragmented (7) (14). Even in upland areas where soils are less fertile, farming based on native crops, such as rooibos tea and cut flowers, is rapidly reducing the angulate tortoise’s natural habitat, while dense stands of alien plants provide a further threat (7). Although the angulate tortoise is commonly kept as a pet (6), little information is available on wild trade in this species.

The angulate tortoise is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in angulate tortoises should be carefully monitored and controlled (1). Tortoises in South Africa and Namibia are protected wildlife, and permits are required for their collection or exportation (8). A number of conservation measures are being undertaken in the Cape Floristic Region, including the removal of alien plants and the expansion of protected areas (7). However, although around 14 percent of this unique region has some level of protection, these protected areas are not thought to be entirely representative of the region’s biodiversity (7), and improved protection of the angulate tortoise’s habitat may be required if the species is not to suffer declines in the future.

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

For more information on tortoises and turtles and their conservation, see:

• World Chelonian Trust:
  http://www.chelonia.org
• Turtle Conservation Fund:
  http://www.turtleconservationfund.org/
• Turtle Survival Alliance:
  http://www.turtlesurvival.org/
• Turtles of the World (CD-ROM), by Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W.:
  http://nlbif.eti.uva.nl/bis/turtles.php?menuentry=inleiding