Grooved tortoise, Spur tortoise, African Spur Thigh tortoise, Sulcata tortoise
The African spurred tortoise is the biggest tortoise from the African mainland, with only the giant island species of Galápagos and Aldabra being bigger. This tortoise of the desert is well camouflaged with its overall sandy colors, having thick yellow-brown to golden skin and a brownish shell. Its wide, oval carapace shows noticeable grooves at its front and back edges and noticeable growth rings on each scute, which become marked, particularly with age. Large scales that overlap cover the front of the forelimbs, while the rear surface of the thighs have two or three large spurs of a conical shape, which gives the species its name.
This tortoise inhabits the Sahara’s southern edge, from Senegal and Mauritania, through Chad, Mali, the Sudan and Ethiopia as far as Eritrea. They also may be found in Somalia and Niger. They live in hot, arid areas, ranging from dry savannahs to desert fringes, where there are usually no permanent water supplies.
These tortoises are very aggressive with each other, starting from when they hatch. Ramming each other and attempts at flipping each other over are behaviors that are common for males. These tortoises like burrowing and are well adapted for it. For tortoises, they are very active and strong. When the weather is too hot or cold, they go into a burrow, which also helps them avoid dehydration, as they depend mostly on metabolic water as well as the moisture from food for water. They remain in their burrows for hours, and if they come across mud, they flip it up onto their backs. If temperatures climb higher than 40 C, they will salivate and smear their forearms with the saliva to help cool down. They are most active during dusk and dawn and usually bask in the morning in order to raise the temperature of their body after the cold of the night.
African spurred tortoises are vegetarians, eating succulent plants both for food and much of the water they need. In the wild, their diet consists of grasses, flowers, cacti, and weeds. In captivity, i.e. in zoos, they eat a range of grasses, berseem, lettuce and morning-glory leaves. Their favorite food is dandelion greens.
African spurred tortoises are polygynous breeders. This means that males will mate with more than one female during the breeding season. Breeding takes place from June to March, though from September to November after the rains it is more common. Males grow aggressive and ram each other to flip over any competition. While they ram and bite one another, they make grunts, croaks, and whistles. During breeding they are very vocal. After mating, females dig several nests before deciding which one is most suitable. A clutch numbers 15 - 30 eggs and on average one egg is laid every 3 minutes. The mother covers the eggs and they incubate for about 8 months. In captivity, the eggs hatch between 90-180 days, the average being 100-120 days. About 2 inches long, hatchlings are yellow, and each scute has a heavy dark brown outline. The young are feisty and active, and will often ram into other hatchlings and objects that are nearby.
African spurred tortoise numbers have rapidly declined due to habitat loss, especially in Mali, Chad, Ethiopia, and Niger, largely because of urbanization, desertification and overgrazing from domestic livestock. Several ethnic groups that inhabit the Sahel, particularly nomadic tribes, eat this species, and it is also trapped for international trade, both as pets and for its body parts that are reportedly used for longevity potions in Japan. Mostly juvenile individuals are the ones captured for trade, so as the African spurred tortoise takes 15 years to become mature, there is serious concern that populations in the wild may not be able to renew themselves, meaning local populations will become extinct.
The IUCN Red List and other sources do not provide the African spurred tortoise total population size. Currently this species is classified as Vulnerable (VU) on the IUCN Red List.