About Causus maculatus (Hallowell, 1842)
Causus maculatus is a small, stout viper. On average, its total length including the tail measures 30–60 cm (12–24 in), and it reaches a maximum total length of approximately 70 cm (28 in), and may grow slightly longer. Its snout is obtuse, with a rounded rostral scale, and a single loreal scale is present. The circumorbital ring is made up of 2–3 preoculars, 1–2 postoculars, and 1–2 suboculars. There are 6 supralabials and 9–10 sublabials, and four of these sublabials are in contact with the sublinguals. There are 2–3 temporal scales. At midbody, dorsal scales are arranged in 17–19 rows. Females have 118–137 ventral scales, while males have 124–144. Females have 14–23 subcaudal scales, and males have 15–26. Within this species' geographic range, ventral scale counts increase from south to north and from east to west; this diagnostic information is attributed to Hughes (1977). Spawls and Branch (1995) provide a slightly different description of the species' body scalation: they note 17–22 rows of dorsal scales at midbody, which are soft and feebly keeled. They also report 124–151 ventral scales in females and 118–154 in males, with the highest counts found in specimens from Uganda and Ethiopia. The species' color pattern typically has a brown base color, which is sometimes grayish, olive, or light green. A series of dark brown or blackish patches run down the back, and this pattern is less distinct on the first quarter of the body. The flanks are sprinkled with black scales. There is extensive variation in the dorsal pattern. Some specimens, especially those from more arid regions, may have no pattern at all, which makes them difficult to identify. Specimens from the Democratic Republic of the Congo are often uniformly brown. The belly may be white, cream, or pinkish-gray. Ventral scales are usually uniformly colored, but sometimes each scale grades from light to dark, giving the belly a finely barred appearance. The head usually has a distinct V-shaped mark. This mark may be solid black in juveniles, but becomes brown with a black outline in adults. Occasionally, a short dark line extends backwards from the back of the eye. C. maculatus is found from Mauritania and Senegal east to western Ethiopia, and south to the Democratic Republic of the Congo and northern Angola. Its type locality is listed as "Liberia, Western Africa." Mallow et al. (2003) mostly cites Spawls and Branch (1995), describing the geographic range as West and Central Africa, from Senegal east to Chad, southeast to the Democratic Republic of the Congo, and northeast into southeastern Sudan. It is also found in the river gorges and low country of southwestern Ethiopia, extending southwest to northern Angola and the Democratic Republic of the Congo. This species occurs in a wide range of habitats, including forests, savanna, and even semi-desert. It can be quite abundant in parts of its range, and has been recorded at altitudes up to 2,400 m (7,900 ft). C. maculatus is oviparous. An adult female typically lays a clutch of 6–20 eggs between February and April, and hatchlings emerge between May and July.
