Home’s hinge-back tortoise (Kinixys homeana)

Also known as: Home’s hinged tortoise, Home’s hinged-backed tortoise
  
French: Kinixys De Home
KingdomAnimalia
PhylumChordata
ClassReptilia
OrderTestudines
FamilyTestudinidae
GenusKinixys (1)
SizeLength: up to 22.3 cm (2)

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

Home’s hinge-back tortoise belongs to a unique group of tortoises that can close themselves entirely within their shells. As the name suggests, this group possess a hinge at the back of the carapace (or shell), that can close off the tortoise’s vulnerable parts, providing excellent protection from potential predators (4). The carapace of Home’s hinge-back tortoise varies in colour from dark brown to tan (2), and is distinguished by the pronounced vertical drop at the end (5). The shape of the carapace also cleverly channels rainwater towards its head for drinking (5). Each forelimb bears five claws and the small head has a hooked upper jaw. Both the limbs and head are brown to yellow (2). Female Home’s hinge-back tortoises are larger than males, but males possess longer and thicker tails (2).

Occurs in West Africa, from Liberia, east to Cameroon, and in the Democratic Republic of Congo (1) (2).

Home’s hinge-back tortoise is a forest tortoise, generally observed in shady places in lowland evergreen forest (6)

The secretive Home’s hinge-back tortoise has adapted its behaviour to tolerate the high heat of its tropical environment. Overheating is a real risk, and so the tortoise rests and moves in the shade (6). When water is not available, Home’s hinge-back tortoise may bury itself below ground and emerge again when the rains come (5). Home’s hinge-back tortoise is omnivorous, consuming both animal and plant food, which is located using the sense of smell as the tortoise makes straight, darting jabs with the head (2). Interestingly, it is one of the most carnivorous terrestrial chelonians in the world (7). Home’s hinge-back tortoise lays oval, brittle-shelled eggs, which are incubated for at least five months. The tiny hatchlings, less than five centimetres long, have flattened, brown carapaces, with no hinge (2). The sex ratio of adults is 1:1, but the females are considerably larger in size than the males (8).

Populations of Home’s hinge-back tortoise are currently declining throughout much of its range, primarily as a result of habitat loss and intensive harvesting (1). The species is captured, even within protected areas, for human consumption, traditional medicine, and for the international pet trade (1) (9). Habitat loss is also occurring, as a result of industrial expansion, agriculture and deforestation (1). Nigerian populations appear to be particularly threatened, as they inhabit fragmented forest patches in the southern part of the country (rather than the extensive forest found in the Congo), and face stronger hunting pressure as a result of greater human populations (9). The Home’s hinge-back tortoise appears to be especially vulnerable to humans during the dry season when the swamps are dry, and humans can access nearly all areas of the forest (9).

Although Home’s hinge-back tortoise is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in this species should be carefully monitored (3), further action is necessary to ensure its survival, such as declaring it a protected species in all countries of occurrence (1). Habitat conservation efforts, such as the establishment and enforcement of protected areas, are also important, but must be coupled with the control of hunting activities if populations of this remarkable tortoise are to survive (9).

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

 

Authenticated (06/08/09) by Dr Luca Luiselli, Senior Researcher in Ecology, Institute Demetra, Rome, Italy.
http://www.intecol.net/pages/002_personal.php?id=lucamlu

  1. IUCN Red List (April, 2009)
    http://www.iucnredlist.org/
  2. Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. (1997) Turtles of the World. ETI Information Systems Ltd, Netherlands.
  3. CITES (November, 2007)
    http://www.cites.org
  4. Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.
  5. Alderton, D. (1988) Turtles and Tortoises of the World. Blandford Press, London.
  6. 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.
  7. Luiselli, L. (2003) Seasonal activity patterns and diet divergence of three sympatric Afrotropical tortoise species (genus Kinixys). Contributions to Zoology, 72(4): 211 - 220. Available at:
    http://dpc.uba.uva.nl/ctz/vol72/nr04/art02
  8. Luiselli, L., Politano, E. and Akani, G.C. (2003) Seasonal incidence, sex-ratio, and population cohorts of hinge-back tortoises (genus Kinixys) in the wild and in bush-meat markets of the Niger Delta, southern Nigeria: are human predation effects random?. Revue de Ecologie - La Terre et la Vie, 58: 243 - 248.
  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.