Cochin forest cane turtle
This rare and little-known species (less than 50 specimens have ever been collected) has an oval, moderately domed carapace (to 13.1 cm) with three low keels. The medial keel, which extends along all five vertebrals, is better developed than the two lateral keels, which only extend along the upper parts of the first three pleurals. All vertebrals are broader than long, and the posteriormost marginals are slightly serrated. The carapace is uniformly bronze or orangish brown to black. The plastron is relatively wide with a posterior notch. The bridge is fairly long, and both the axillary and inguinal scutes are very small; the inguinals may be absent. The plastral formula is: abd >< pect > hum >< fem > an > gul. The plastron is uniformly yellow to orange with a black blotch on both the pectoral and abdominal scutes at the bridge. The head is of moderate size and the upper jaw has a strong medial hook. The front of the head and the jaws are yellow, and a red spot occurs on the tip of the snout. The iris of the eye is reddish, and red or pink pigment also occurs on the upper eyelid. This pigment may extend to the dorsal surface of the head. Posterior surface of the head and neck are brown to black, limbs and tail are pale brown. Enlarged scales are present on the anterior surface of the forelegs, and the hind foot is somewhat club shaped. No webbing occurs on the toes, but their claws are well-developed.
Males have thicker, longer tails with the vent beyond the carapacial rim, concave plastra, and better developed spurlike protuberances on their hindlegs. Females are not as colorful as males, and tend to be slightly larger. Mature females develop a movable plastron resulting from erosion of the bony suture between the hypoplastron and carapace (Moll et al., 1986).
Heosemys silvatica is restricted to the region of Cochin in southwestern India. It has been collected only rarely since 1911.
Heosemys silvatica inhabits upland, shady, dense, evergreen forests above 300 m, not necessarily near free water, and lives in short underground burrows (Henderson, 1912), or hides under dead leaves and logs or in rock crevices in spiny cane groves (Vijaya, 1982a; Moll et al., 1986).
Breeding apparently occurs in October and November, just after the monsoon (Vijaya, 1982a; Das, 1991, 1995). Males develop bright-red pigment on the head at this time. A female collected in October in Kerala laid two eggs (44-45 x 22.5-23.5) on 22 December at the Madras Snake Park Trust (Whitaker, 1983; Moll et al., 1986). The hatchling carapace is about 44 mm (Ewert, 1979).
Wild turtles feed on fallen fruits and leaves and invertebrates such as millipedes, mollusks, and beetles (Vijaya, 1982a; Whitaker, 1983); Henderson (1912) reported that captives were entirely herbivorous.
H. silvatica is nocturnal or crepuscular and apparently rare or very secretive. It is sympatric with Indotestudo forstenii.
Heosemys silvatica shares several characters with Geoemyda spengleri, and Moll et al. (1986) and McCord et al. (1995) would place this and other species of Heosemys in the genus Geoemyda.
IUCN Red List Status (1996)
Endangered (B1+2c); listed as Geoemyda silvatica.