Gray, 1844
Central Asian tortoise
Recognition
The rounded carapace (to 22 cm) is almost as broad as long and flattened dorsally (about twice as long as high). The highest point is near the center, and the sides are not abruptly descending. A weak cervical notch is present, and the posterior rim is not greatly flared, but may be slightly serrated. The cervical scute is usually long and narrow, but the vertebrals are all broader than long; the 5th is expanded. Areolae of the vertebral and pleural scutes are slightly raised and surrounded by growth annuli. There are usually 11 marginals on each side, and the supracaudal is undivided. The carapace ranges in color from totally light brown to yellowish brown with extensive dark-brown pigment on each scute. The plastron is well-developed, but lacks the movable hinge between the abdominal and femoral scutes that occurs in other Testudo species. The plastral forelobe is not upturned, tapers to the front, and is slightly longer and narrower than the hindlobe, which bears a posterior notch. The plastral formula is: abd > gul >< hum >< an > fem > pect; the paired gulars are thickened and extend slightly beyond the carapacial rim. The broad bridge has a small axillary and usually only a single small inguinal that does not touch the femoral. The bridge is usually yellow, but the plastron is black with yellow seams. The head is moderate in size with a nonprotruding snout and a hooked, often tricuspid upper jaw. Its large prefrontal is divided longitudinally; the frontal is large and usually undivided, and the other head scales are small. The head is yellowish brown with dark jaws. Limbs are also yellowish brown. Five or six longitudinal rows of large overlapping scales lie on the anterior surface of each foreleg. Spurlike scales are present on each heel, and blunt tubercles on each thigh. The tail ends in a horny claw.
Males have longer, thicker tails with the vent close to the tip. Females are larger than males.
Distribution
The Central Asian tortoise ranges from the southeastern coast of the Caspian Sea southward through Iran, Afghanistan, and Pakistan, and eastward through Kazakhstan to Xinjiang, China.
Geographic Variation
Three subspecies are considered valid by Iverson (1992) and David (1994). The Central Asian tortoise Testudo horsfieldii horsfieldii Gray, 1844 is found from Iran, Afghanistan, and Pakistan to western Xinjiang, China. It has a rounded carapace (to 22 cm) with convex sides, the posterior marginals only slightly flared or serrated, and the ground color yellow with some small dark mottles. The anterior lobe of the plastron is not upturned and is narrower than the plastral hindlobe. T. h. kazakhstanica (Chkhikvadze, 1988), the Kazachstan tortoise, occurs in Kazakhstan and Turkmenistan. Its more rectangular carapace (to 21 cm) has only slightly convex sides, the posterior marginals upturned and at best only slightly serrated, and the ground color yellow, horn, or yellowish green with dark mottles, spots, or streaks covering most of the scute surfaces. The anterior lobe of its plastron can be equal in width to the hindlobe. The Kopet-Dag tortoise T. h. rustamovi (Chkhikvadze, Amiranashvili and Ataev, 1990) is found only in the Kopet-Dag region of southwestern Turkmenistan and western Kazakhstan. Its carapace is smaller (to only 17 cm), rounded with convex sides, with posterior marginals serrated, and the ground color yellow with dark mottling. The plastral forelobe is narrower than the hindlobe.
Many of the characters supposedly separating the subspecies of T. horsfieldii overlap; a good statistical analysis of geographic variation in this species is required.
Habitat
Testudo horsfieldii is found in a variety of dry habitats, ranging from rocky deserts, sandy and loamy steppes, to rocky hillsides. In these habitats, they most frequently occur in oases, along brooks, or near springs, where vegetation is more lush.
Natural History
The peak activity period is in April and May. In the north they hibernate in plugged burrows during the winter, and in the south they may aestivate in the warmer months. Females mature by their 10th year (Das, 1995).
In Russia, mating takes place in the spring following emergence from the winter retreats. Nests, with cavities deeper than 7 cm, are dug in June with hatching in August or September in the south; the young may overwinter in the nest and not emerge until the next June in Russia (Nikolskii, 1915).
Possibly 2-4 clutches of 2-20 (usually 3-5) eggs (Das, 1991, 1995) are laid each year. Eggs are elongated (41-50 x 26-35 mm) with a hard smooth shell. The yellow and black hatchlings have rounded carapaces (29-50 mm) with posteriorly serrated rims.
Natural foods consist solely of vegetation: grasses, flowers, fleshy leaves of plants, and fruits. These tortoises may not drink, but instead subsist on metabolic water produced from food. During the hot periods of the day and at night, they remain in burrows or under boulders or rock outcroppings.
IUCN Red List Status (1996)
Vulnerable (A2d).