African spurred tortoise

The African spurred tortoise is apart of the:

• Animalia kingdom
• Bilateral Subkingdom
• Deuterostomia Infrakingdom
• Chordata Phylum
• Vertebrata Subphylum
• Gnathostomata Infraphylum
• Tetrapoda superclass
• Reptilia class
• Testudines order
• Crytodira suborder
• Testudinoidea superfamily
• Testudinidae family
• Centrochelys genus[4]

The taxonomic species name is Centrochelys sulcata and is otherwise known as C. sulcata. Its specific name sulcata is from the Latin word sulcus meaning "furrow" and refers to the furrows on the tortoise's scales.[4]. At first the species was labeled as Testudo sulcata. As time has passed since the species was first classified, C. sulcata has been referred to by several different designations. There are no recognized subspecies despite there being two separate populations, one in Western Africa and the other in Eastern Africa. There are also three different, yet similar, haplotypes. One haplotype is found in and closely around Sudan, another is found in the western portion of their range, and the last haplotype is found in Senegal, Mali, and Sudan.[5]

Young C. sulcata

Range of African Tortoise

The African spurred tortoise is native to the Sahara Desert and the Sahel, a transitional ecoregion of semiarid grasslands, savannas, and thorn shrublands found in the countries of Burkina Faso, the Central African Republic, Chad, Eritrea, Ethiopia, Mali, Mauritania, Nigeria, Senegal, Saudi Arabia, Sudan, Yemen and possibly in Somalia, Algeria, Benin, and Cameroon. It is possibly extirpated from Djibouti and Togo.[1][5] They are found on hills, stable dunes, and flat areas with shrubs and high grass. They also like to settle in areas with interrupted streams or rivers.[5] In these arid regions, the tortoise excavates burrows in the ground to get to areas with higher moisture levels, and spends the hottest part of the day in these burrows.[6] This is known as aestivation. In the wild, they may burrow very deep; up to 15 m deep and 30 m long.[7] Plants such as grasses and succulents grow around their burrows if kept moist and in nature they continue to grow for the tortoise to eat if the soil is replenished with its feces.[6] Sulcata tortoises found in the Sudanese part of their range may reach significantly greater size at maturity than those found in other regions.[8]

C. sulcata is the largest species of tortoise in Africa and is also third-largest species of tortoise in the world after the Galapagos tortoise and Aldabra giant tortoise.[9] The species is the largest of the mainland tortoises.[7] Males have an average mass of about 81 kg, but some males have been recorded at over 100 kg with one wieghing more than 120 kg. They have a straight carapace length of around 86.0 cm in males. Females have a straight carapace length of about 57.8 cm. Males of a curved carapace length of about 101.0 cm and females have approximately 67.0 cm of curved carapace length. They grow from hatchling size (2–3 in) very quickly, reaching 6–10 in (15–25 cm) within the first few years of their lives. They reach sexual maturity after 10 to 15 years. in captivity their life span is around 54 years, but in the wild their lifespan is unknown, but it is believed to exceed 75 years.[10][5]

African spurred tortoise at the Las Vegas Zoo

Sulcata tortoises are herbivores. Primarily, their diets consist of many types of grasses, plants (especially succulent plants),[11] and hay. Their overall diet should be high in fiber and very low in protein. Flowers and other plants including cactus pads can be consumed. Fruits such as apples can be given as a treat once in a great while. Various vegetables such as endive, dandelion greens, and dark leafy greens are healthier. As the tortoises get older and their jaws stronger, it is recommended to allow them to eat hays such as Orchard and Timothy Hay.[12][13][14] Certain vegetables can lead to serious medical issues. Kale, brussel sprouts, and broccoli can be added to their diet rarely, but are known to cause hypothyroidism. Parsley, collard greens, and romaine lettuce should be excluded from their diets entirely, as they are too high in calcium oxalate.[14]

A diet too high in protein will lead to the tortoise growing too fast, and this is known to cause metabolic bone disease, or "pyramiding."[14]

Copulation takes place right after the rainy season, during the months from September through November with breeding actions occur in the morning.[5][6] Male C. sulcata are extremely territorial.[5] Males combat each other for breeding rights with the females and are vocal during copulation.[6]. Larger males tend to always win sexual combat.[5]

Sixty days after mating, the female begins to roam looking for suitable nesting sites.[6] For five to fifteen days, four or five nests may be excavated before she selects the perfect location in which the eggs will be laid.[6] Females tend to lay around two to three clutches of eggs with each clutch containing fourteen to forty eggs.[15]

Immature Centrochelys sulcata in East Bay Vivarium

Loose soil is kicked out of the depression, and the female may frequently urinate into the depression.[6] Once it reaches about two feet (60 cm) in diameter and 3–6 in (7–14 cm) deep, a further depression, measuring some eight inches (20 cm) across and in depth, will be dug out towards the back of the original depression.[6] The work of digging the nest may take up to five hours; the speed with which it is dug seems to be dependent upon the relative hardness of the ground.[6] It usually takes place when the ambient air temperature is at least 78°F (27°C).[6] Once the nest is dug, the female begins to lay an egg every three minutes.[6] Clutches may contain 15–30 or more eggs.[6] After the eggs are laid, the female fills in the nest, taking an hour or more to fully cover them all.[6] Incubation should be 86 to 88 °F, and will take from 90 to 120 days.

C. sulcata is currently ranked as an endangered species.[16] The species faces threats from livestock as they have to compete for resources.[17] The main source of resource competition African spurred tortoises face is from cattle which also graze on grass. The effects of competition for grazing land is compounded by wild fires which can destroy large portions of grass land which kills and rescues the resources available to C sulcata. [18] They also face threats from the pet trade as they are over harvested from their natural environment.[19] Other threats that the species face are habitat loss due to climate change and predators which hunt the tortoises or their eggs.[20][21] The main method of conservation has been reintroduction programs. These sorts of reintroduction programs have been implemented in Ferlo, and Sengal. There also captive colonies in several countries. Most of these reintroduction programs and captive colonies can be found in protected national parks and wildlife sanctuaries.[16] There are hopes to expand reintroduction programs by involving tortoise owners. The goal would be to establish a breeding programs with the owners where all hatchlings would be reintroduced.[22]

African Spurred Tortoise at the Las Vegas Zoo

African spurred tortoises are passive and docile pets.[23] They are almost never aggressive and barely ever show territorial behavior. This docile behavior is complimented by their slow speed and silence. Despite their docile attitude, the tortoise should not be handled often as handling will cause stress. Stress can lead to health problems and premature death. They are also very curious, and can end up stuck on their backs, needing help getting flipped back over. African Spurred Tortoises have a lifespan of around 70 years, which means that they are a long term commitment.[23]

The ideal enclosure for the African spurred tortoise is an outdoor pen where they will be able to construct a burrow. A fence of around two feet is recommended with some parts of the fence being extended underground. They prefer high temperatures and thrive in temperatures as high as 100 degrees Fahrenheit when they have a borrow to go into to cool off. When in captivity they should also have access to heating systems to keep the temperature of an enclosure above 60 degrees Fahrenheit for when the temperature drops during the night. If the tortoise is being kept inside they need access to artificial means of sunlight.[23] The enclosure should also be kept somewhat humid. Humidity should be kept around 40-50 percent as any higher than that can lead to repository issues. These tend to be fungal infections, but shell rot is also common.[23]

They require high fiber diets (grasses and hays) as many "wet" vegetables can cause health problems in large quantities. Red leaf lettuce, prickly pear cactus pads, hibiscus leaves, hay from various grasses and dandelions are some of the better foods to make up the bulk of their diet. They will attempt to eat most types of plants eventually and some common garden plants can be very toxic to them, such as azaleas. They will eat such things as caterpillars and snails if given the opportunity, but this also should be a very small portion of their diet. Calcium should also be another small portion of their diet to help with shell growth. The tortoises should also avoid fruits and proteins.[23]

Wikimedia Commons has media related to African Spurred Tortoise.

• ARKive – images and movies of the African spurred tortoise (Geochelone sulcata)