(Gmelin, 1789)
Speckled padloper
Recognition
This is one of the smallest of all turtles, reaching a maximum carapace length of 9.6 cm; the average length is 85-90 mm (Baard, 1994). The slightly domed carapace is dorsally flattened, scarcely indented in the cervical region, and has the anterior and posterior marginals expanded, reverted, and serrated. The cervical scute is small; most vertebrals are broader than long, but the 1st may be as long as broad. Additional vertebrals are sometimes present, raising the total from five to six or seven; and the young have a medial keel (Loveridge and Williams, 1957). There are 11-12 marginals, usually 11, on each side, and the supracaudal is undivided. The carapace is cream colored to yellowish green with numerous black spots or radiations. The plastron is also cream to yellow, and has faded brown blotches and radiating lines. Its forelobe is anteriorly truncated; the hindlobe has an anal notch. The plastral formula is: abd > hum > an > gul >< pect >< fem. Each bridge has a single inguinal in contact with the femoral scute. The head is moderate in size, with a nonprojecting snout and a weakly hooked upper jaw. The small prefrontal scale is longitudinally divided, and is followed by several other small scales. Head and neck are yellow and dorsally spotted with black. The forelimbs are anteriorly covered with large overlapping scales in five or six longitudinal rows. Each thigh bears a very large conical tubercle. Five claws occur on each forefoot, and the limbs and tail are yellow to tan.
The smaller males have posteriorly concave plastra with deeper anal notches, and longer, thicker tails.
Distribution
Homopus signatus is confined to Little Namaqualand, from Kleinzee and Springbok southward to Graafwater and Clanwilliam, and eastwards to Calvinia. Namibian records (Greig and Burdett, 1976; Boycott, 1986) are in error (Branch et al., 1995).
Geographic Variation
Two subspecies seem valid (Boycott, 1986). Homopus signatus signatus (Gmelin, 1789), the Namaqualand speckled padloper, has a strongly grooved carapace with depressed scute areolae, black radiations, strongly serrated posterior marginals, and the cervical scute wider than long; it occupies the northern and eastern portions of the range. The southern speckled padloper H. s. cafer (Daudin, 1802) has a slightly grooved carapace with flattened or raised scute areolae, fine black dashes on a orange to salmon ground color, weakly serrated posterior marginals, and the cervical scute longer than wide; it includes Pseudomopus signatus peersi Hewitt, 1935. This subspecies is found in the southwestern portion of the range about Clanwilliam and Goergap. Intergrades between the two subspecies are found in the Calvinia region.
Habitat
Homopus signatus lives in rocky landscapes along dry watercourses and mountains with elevation to 1000 m (Homopus s. signatus biotope) (Boycott, 1989b). Loveridge and Williams (1957) and Baard (1994) reported they were fairly numerous on granite koppies near Bitterfontein, Western Cape Province.
Natural History
Eglis (1962) and Loehr (1997a) reported olfactory movements, associated with courtship, consisting of stiffly executed, left-to-right pendulous sweeps of the head by both males and females. One or two 34-35 x 25-26 mm eggs are laid in summer (Boycott, 1989b). In captivity, 1-4 clutches of single eggs are produced in spring and summer, with intervals of 25-43 days. Nests excavated under overhanging rock slabs by means of forelimbs and hindlimbs, or the eggs are deposited in rock crevices. The incubation period lasts 109-129 days at temperatures between 26°C (night) and 32°C (day). Hatchlings have 30.8-32 mm carapaces and weigh 7-10 g (Loehr, 1997a, in press).
Homopus s. signatus has been found to aestivate in easterly facing crevices in December-January near Springbok in Namaqualand, Northern Cape (Bayoff, 1995). In September-October, when night temperatures can drop below 0°C at this location, the species was observed wandering near the edges of koppies at day time (Loehr, 1996).
In the wild, juveniles have been found feeding on flowers of an unidentified species of grass and on leaves of a shrub of the genus Wiborgia, (Loehr, 1996; Loehr and Harris-Smith, in press). In captivity, adult specimens could only be provoked to start feeding by offering flowers (Taraxacum, Vicia, Trifolium, Belle) (Loehr, 1997a, in press).
IUCN Red List Status (1996)
Lower risk: near threatened.