African spurred tortoise (Centrochelys sulcata)
|Also known as:||Grooved tortoise|
|Synonyms:||Geochelone sulcata, Testudo calcarata, Testudo sulcata|
|Spanish:||Tortuga Con Púas|
|Size||Maximum carapace length: 83 cm (2)|
Maximum weight: 105 kg (2)
The African spurred tortoise is classified as Vulnerable (VU) on the IUCN Red List (1), and listed on Appendix II of CITES (3).
The African spurred tortoise (Centrochelys sulcata) is the largest tortoise of the African mainland, and is surpassed in size only by the giant island species from Aldabra and Galápagos (4) (5). This desert-dwelling tortoise is well camouflaged by its overall sandy coloration (6), having thick golden to yellow-brown skin and a brownish carapace (4) (5). The African spurred tortoise has a broad, oval carapace which displays prominent serrations at the front and back margins and conspicuous growth rings on each scute, which become particularly marked with age (4). Large, overlapping scales cover the front surface of the forelimbs, while the hind surface of the thigh bears two or three large conical spurs, from which the species earns its name (4) (5).
The African spurred tortoise is found along the southern edge of the Sahara, from Senegal and Mauritania, east through Mali, Chad, the Sudan and Ethiopia to Eritrea. This species may also be found in Niger and Somalia (1).
The African spurred tortoise lives in hot, arid regions ranging from desert fringes to dry savannahs, where permanent water supplies are usually lacking (4) (5) (7).
Most activity occurs during the rainy season (July to October), primarily at dawn and dusk, when this tortoise forages for succulent plants and annual grasses (4) (5). Like many species, the African spurred tortoise often spends the early morning basking to raise its body temperature after the night chill. During the dry season, adults often aestivate in their cool, moist burrows to prevent dehydration, while hatchlings are thought to enter small mammal burrows for the same purpose (4) (5).
Mating can take place at any time from June through to March, but reportedly occurs most frequently after the rainy season from September to November (4) (5). Four or five nests may be dug before the female decides upon the one in which to lay her clutch of 15 to 30 eggs. Once deposited, these eggs incubate underground in the covered nest for approximately eight months (4) (5). From the moment they hatch, African spurred tortoises are very aggressive towards one another, and especially so at breeding times (4) (5). Males in particular can commonly be seen ramming into each other and attempting to flip one another over (4).
African spurred tortoise populations have declined rapidly in the face of habitat loss, particularly in Mali, Chad, Niger and Ethiopia, largely as a result of urbanisation, overgrazing by domestic livestock and desertification (4). Several ethnic groups in the Sahel, especially nomadic tribes, eat the African spurred tortoise (3). The already vulnerable position of the species has been compounded in recent years by an increase in capture for international trade, as pets and for body parts reportedly used to make longevity potions in Japan (3). It is primarily juvenile African spurred tortoises that are captured for trade and, as this species takes 15 years to reach maturity, there is grave concern that generations in the wild may be unable to renew themselves, resulting in extinction of local population (3).
Varying degrees of legal protection are afforded to the African spurred tortoise across its range, but illegal capture clearly continues in certain areas. Furthermore, although the African spurred tortoise is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), with a zero annual export quota for specimens removed from the wild and traded for primarily commercial purposes, it is difficult for authorities to differentiate between wild and captive-bred specimens. Enforcement against fraud and smuggling is evidently insufficient, especially between Mali, Ghana and Togo, and this problem needs to be addressed. African spurred tortoises breed fairly easily in captivity, and the United States reportedly now breeds enough specimens to supply domestic demand, while the specimens exported from the U.S. to Japan are also declared to be from breeding operations (3). Unfortunately, arid regions in which this species is found are not often proclaimed as national parks or reserves (7), but where the African spurred tortoise does occur in protected areas, it is doing well (3). This is the case for populations in the Parc du Diawling in Mauritania and the Parc du W in Niger (3).
In Senegal, the African spurred tortoise is a symbol of virtue, happiness, fertility and longevity and, as such, conservation programmes have been easier to promote in this country (4). In 1993, a programme to help this tortoise was established by the Fondation Rurale pour le Developpement, a Senegalese association, supported by Station d'Observation et de Protection des Tortues des Maures(SOPTOM), a European non-governmental organisation. A breeding centre, an information centre and a protection centre were created in Sangalkam in Senegal, and a restocking project was established. Additionally, tortoises from the Netherlands have been repatriated to Senegal (3). However, with advancing desertification, the revered status of the African spurred tortoise in this country may not be enough to protect it.
For more information on the African spurred tortoise see:
CITES: Consideration of Proposals for Amendment of Appendices I and II Prop. 11.38.:
Turtles of the World (CD-ROM), by Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W.:
Authenticated (29/01/2008) by Dr. Day Ligon, Department of Biology, Missouri State University.
- Aestivation: period of dormancy occurring in hot, dry periods, analogous to hibernation in winter.
- Carapace: the top shell of a turtle. In arthropods (insects, crabs etc), the fused head and thorax (the part of the body located near the head) also known as ‘cephalothorax’.
- Desertification: a process of sustained decline of the biological productivity of arid and semiarid land; the end-result is desert, or skeletal soil that is irrecoverable.
- Sahel: A semiarid region of north-central Africa south of the Sahara desert that stretches across six countries from Senegal to Chad.
- Scute: One of the large keratinous scales on the shell of a turtle or tortoise.
IUCN Red List (September, 2008)
Tortoise Trust (December, 2006)
CITES: Consideration of Proposals for Amendment of Appendices I and II Prop. 11.38. (December, 2006)
Animal Diversity Web (December, 2006)
Turtles of the World (CD-ROM), by Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. (December, 2006)
WhoZoo: Animals of the Fort Worth Zoo (December, 2006)
Seneca Park Zoo (December, 2006)