Serrated hinge-back tortoise  (Kinixys erosa)

Serrated hinge-back tortoise

Facts

Also known as:eroded hinge-back tortoise and forest hinged tortoise
Kingdom Animalia
Phylum Chordata
Class Reptilia
Order Testudines
Family Testudinidae
Genus Kinixys (1)
Size Length: up to 37.5 cm (2)

Status

Classified as Data Deficient (DD) on the IUCN Red List 2007 (1) and listed on Appendix II of CITES (3).

Description

Hinge-backed tortoises (species belonging to the genus Kinixys) have the remarkable ability to shut themselves entirely within their shells (4). This is due to the hinge at the back of the carapace (or shell) that can close off the tortoise's hind legs and tail (4). The serrated hinge-back tortoise has a slightly concave shell that is reddish-brown and yellow (2) (5). The scales at the rear of the shell have upturned edges giving, as their name suggests, a serrated appearance (2). The head is rounded and the tail has a small, claw-like protuberance at the tip. Male serrated hinge-back tortoises can be distinguished from females by their longer and thicker tails (2).

Range

Occurs in West Africa from the Gambia, east to the Democratic Republic of Congo and Uganda, and south to southern Angola (6).

Habitat

The serrated hinge-back tortoise inhabits low to mid-altitude forest (2), where it is nearly always observed in shady areas (7). It is reportedly fond of swampy areas but in Ghana it occurs mostly in dry clearings and open areas (2)

Biology

The serrated hinge-back tortoise can often be found under logs, in holes or in leaf litter, where it uses its strong legs and upturned shell edges to wedge itself into a protected shelter (2). When in the open, the hinge-back tortoise can defend itself by withdrawing its limbs and closing its shell (2). By resting and moving in the shade, the serrated hinge-back tortoise avoids over-heating in its hot, tropical environment (7). It is also a surprisingly reasonable swimmer and will frequently seek out marshes and river banks in the forest (4).

Like all Kinixys species, the serrated hinge-back tortoise is omnivorous, and feeds on fungi, fruits, plant matter, invertebrates and even carrion (2) (8). During the breeding season it is thought that males fight (2), competing for females to mate with. Females lay several clutches of four eggs on the ground and cover them up with leaves (2) (4).

Threats

Hinge-back tortoises are actively hunted by humans in sub-Saharan Africa, mainly for domestic consumption (9). Their flesh is highly prized as food by some forest peoples, and hunting is often carried out by dogs which locate the tortoise by its distinctive smell (2). At present there are no other known threats to this species; they are so widespread in the central African forests that they are probably not vulnerable to the impacts of habitat destruction (2).

Conservation

Whilst in some areas the serrated hinge-back tortoise is hunted, in others, this tortoise is worshipped by local communities. They believe it brings happiness, is a symbol of peace and a sign of abundant children (9). This ‘holy' status may afford some populations a degree of protection. The serrated hinge-back tortoise is listed on Appendix II of he Convention on International Trade in Endangered Species (CITES), meaning that international trade in this tortoise should be carefully monitored to ensure it is compatible with its survival (3). However, as there is insufficient information to determine the status of the hinge-back tortoise in the wild (1), it can not be determined if the tortoise is being taken from the wild at sustainable levels. Therefore, further research and surveys are required to ensure that this trade is not putting the serrated hinge-back tortoise at risk from extinction.

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Carrion: Dead flesh.
Invertebrates: Animals with no backbone.
Omnivorous: An organism that feeds on both plants and animals.

References

  1. IUCN Red List (September, 2007)
    http://www.iucnredlist.org
  2. Spawls, S., Howell, K., Drewes, R.C. and Ashe, J. (2004) Field Guide to the Reptiles of East Africa. Christopher Helm Publishers Ltd, London.
  3. CITES (October, 2007)
    http://www.cites.org
  4. Burnie, D. (2001) Animal. Dorling Kindersley, London.
  5. Alderton, D. (1988) Turtles and Tortoises of the World. Blandford Press, London.
  6. Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. (1997) Turtles of the World. ETI Information Systems Ltd, Netherlands. Available at:
    http://ip30.eti.uva.nl/BIS/turtles.php
  7. Luiselli, L. (2005) Aspects of comparative thermal ecology of sympatric hinge-back tortoises (Kinixys homeana and Kinixys erosa) in the Niger Delta, southern Nigeria. African Journal of Ecology, 43 (1): 64 - 69.
  8. Luiselli, L. (2003) Seasonal activity patterns and diet divergence of three sympatric Afrotropical tortoise species (genus Kinixys). Contributions to Zoology, 72 (4): 211 - 220.
  9. Luiselli, L. (2003) Comparative abundance and population structure of sympatric Afrotropical tortoises in six rainforest areas: the differential effects of “traditional veneration” and of “subsistence hunting” by local people. Acta Oecologica, 24 (3): 157 - 163.