Gray, 1831b
Bell's hinge-back tortoise
Recognition
This is the most widespread and best known of the Kinixys. Its elongated carapace (to 22 cm) is domed with a flat, sometimes slightly keeled, dorsal surface, sloping sides, the anterior marginals not or only slightly flared, and the posterior marginals not flared and only slightly reverted and serrated. There is, at best, only a shallow indentation at the cervical region, and the posterior portion of the carapace slopes steeply to the marginals. An elongated cervical scute is usually present, although in some it is broad and in others tiny. Vertebrals 2-5 are wider than long and the 5th is flared; the 1st becomes longer with age until it may be longer than wide. A disrupted keel may be present in the form of a narrow longitudinal ridge at the center of each vertebral in younger individuals, but this is usually lost with age. Normally 11 (9-12) marginals lie on each side, and the single supracaudal is undivided. The center of each carapacial scute is yellow to reddish brown while the surrounding growth annuli are dark brown or black; the carapacial pattern, however, is quite variable. The thickened, paired gulars project at best only slightly beyond the carapacial rim, and may lack a shallow notch. The short plastral hindlobe may not be notched posteriorly. There are two to four small axillary scales and one large inguinal (in contact with the femoral) on each bridge. The plastral formula is: abd > hum > fem >< gul > pect > an. The plastron is yellow with black radiations. The brown or black to yellow or tan head is small to moderate with a non-projecting snout and an upper jaw which may or may not be hooked. Its large prefrontal scale may not be subdivided or longitudinally divided, the large frontal is occasionally longitudinally divided, and other head scales are small and irregularly shaped. The forelimbs have on their anterior surfaces large, overlapping scutes in five to nine longitudinal rows. Each thigh lacks enlarged tubercles, but the heel may have spurlike scales. Each forefoot has four or five claws. The tail ends in a clawlike tubercle. The limbs and tail are grayish brown.
The karyotype consists of 52 chromosomes: 26 macrochromosomes and 26 microchromosomes (Killebrew and McKown, 1978).
Males have longer, thicker tails and concave plastra.
Distribution
Kinixys belliana occurs from Somalia southward to Swaziland and Kwazulu-Natal and westward into the Democratic Republic of Congo and across West Africa to Senegal; it may have been introduced on Madagascar. Its range generally skirts the rainforests of tropical Africa.
Geographic Variation
Kinixys belliana is quite variable, and many names have been applied to its populations. However, only two subspecies are currently considered valid. K. b. belliana Gray, 1831b, the eastern hinge-back tortoise, ranges in eastern Africa from Somalia and Ethiopia to the northeastern Democratic Republic of Congo southward to Uganda, southern Malawi, Zimbabwe, and Zululand, and has apparently been introduced into Madagascar. It usually has five claws on each forefoot, the pectoral midseam 26-69% of the length of the combined midseams, and 21-60% of the abdominal midseam. This subspecies now includes those tortoises formerly assigned to K. b. mertensi Laurent, 1956; K. b. zombensis Hewitt, 1931; and Madakinixys domerguei Vuillemin, 1972 (Obst, 1978; Broadley, in Swingland and Klemens, 1989; Broadley, 1993). The western hinge-back tortoise K. b. nogueyi (Lataste, 1886) occurs in western Africa from Senegal eastward to Cameroon and the Central African Republic. It has only four claws on each forefoot, the pectoral midseam 28-39% of the length of the combined gular and humeral midseams, and 22-36% of the abdominal midseam.
Habitat
Kinixys belliana is a savannah, dry brush, and grassland species, and occurs where there are distinct wet and dry seasons (Kinixys b. belliana biotope). This species is common in the East African coastal mosaic of dune forest and hygorophilous grassland, entering miombo mesic savannah. It is forced to aestivate during the dryer periods, and, at such times, has been found in mud bottoms of drying waterholes.
Natural History
Nesting may occur in May. The eggs have brittle shells and are oval to elongated (41-45 x 28-38 mm); two to four compose a clutch. The hatchling carapace is not spinose, and is about 45-47 mm long; in color, hatchlings are either uniformly yellowish, reddish, or olive brown, or the areolae may be deep brown surrounded by a yellow border.
K. belliana is omnivorous, feeding on fallen fruits, sugar cane, fungi, grasses, sedges, and insects; Broadley (1989a) reports it prefers milipeds, but it also takes snails, which are eaten after shells are broken. Captives will eat fruits, such as bananas, mangos, apples, pears, tomatoes, romaine lettuce, and, occasionally, canned dog food.
IUCN Red List Status (1996)
Not listed.