Rhinocerous viper ~ Bitis nasicornis
Species: B. nasicornis
Large and stout, ranging in length from 72 cm to 107 cm. Females become larger than males.
B. nasicornis, adult.The head is narrow, flat, triangular and relatively small compared to the rest of the body. The neck is thin. They have a distinctive set of 2-3 horn-like scales on the end of their nose, the front pair of which may be quite long. The eyes are small and set well forward. The fangs are not large: rarely more than 1.5 cm in length.
Midbody there are 31-43 dorsal scale rows. These are so rough and heavily keeled that they sometimes inflict cuts on handlers when the snake struggles. There are 117-140 ventral scales and the anal scale is single.
The color pattern consists of a series of 15-18 blue or blue-green oblong markings, each with a lemon-yellow line down the center. These are enclosed within irregular black rhombic blotches. A series of dark crimson triangles run down the flanks, narrowly bordered with green or blue. Many of the lateral scales have white tips, giving the snake a velvety appearance. The top of the head is blue or green, overlaid with a distinct black arrow mark. The belly is dull green to dirty white, strongly marbled and blotched in black and gray. Western specimens are more blue, while those from the east are more green. After they shed their skin, the bright colors fade quickly as silt from their generally moist habitat accumulates on the rough scales.
Primarily nocturnal, they hide during the day in leaf litter, in holes, around fallen trees or tangled roots of forest trees. Their vivid coloration actually gives them excellent camouflage in the dappled light conditions of the forest floor, making them almost invisible. Although mainly terrestrial, they are also known to climb into trees and thickets where they have been found up to 3 m above the ground. This climbing behavior is aided by a tail that is prehensile to a certain extent. They are sometimes found in shallow pools and have been described as powerful swimmers.
B. nasicornis, juvenile.They are slow moving, but capable of striking quickly, forwards or sideways, without coiling first or giving a warning. Holding them by the tail is not safe; as it is somewhat prehensile, they can use it to fling themselves upwards and strike.
They have been described as generally placid creatures; less so than B. gabonica, but not as bad-tempered as B. arietans. When approached, they often reveal their presence by hissing. Said to produce the loudest hiss of any African snake — almost a shriek.