Boomslang

The boomslang ( or ; Dispholidus typus) is a highly venomous snake in the family Colubridae. The species is native to Sub-Saharan Africa.

Etymology

Its common name means "tree snake" in Dutch and Afrikaans – boom meaning "tree", and slang meaning "snake". In Afrikaans, the name is pronounced [ˈbuəmslaŋ].

Taxonomy

The boomslang is a colubrid snake within the subfamily Colubrinae. It belongs to the genus Dispholidus, which contains two other species, D. pembae and D. punctatus.

The boomslang is thought to be closely related to members of the genera Thelotornis, Thrasops, Rhamnophis, and Xyelodontophis, with which it forms the taxonomic tribe Dispholidini.

Close relationships can be shown in the cladogram below:

Subspecies

Two subspecies are recognised, including the nominotypical subspecies.

D. t. kivuensis Laurent, 1955

D. t. typus (A. Smith, 1828)

The trinomial authority in parentheses for D. t. typus indicates that the subspecies was originally described in a genus other than Dispholidus.

Description

The average adult boomslang is 100–160 centimetres (3.3–5.2 ft) in total length (including tail). Some exceed 183 centimetres (6.00 ft). The eyes are exceptionally large, and the head has a characteristic egg-like shape. Colouration is highly variable. Males are light green with black or blue scale edges, but adult females may be brown demonstrating sexual dimorphism.

Weight varies from 175 to 510 g (0.386 to 1.124 lb), with an average weight of 299.4 g (0.660 lb).

In this species, the head is distinct from the neck and the canthus rostralis is distinct. The pupil of the very large eye is round. The boomslang has excellent eyesight and often moves its head from side to side to get a better view of objects directly in front. The maxillary teeth are small anteriorly, seven or eight in number, followed by three very large, grooved fangs situated below each eye. The mandibular teeth are subequal. The body is slightly compressed. The dorsal scales, which are arranged in 19 or 21 rows, are very narrow, oblique, strongly keeled, with apical pits. The tail is long, and the subcaudal scales are paired. Ventral scales are 164–201; the anal plate is divided; and the subcaudals are 91–131.

Geographic range

The boomslang is endemic to Sub-Saharan Africa, from The Gambia, Guinea, Senegal and most of Western Africa (including Benin, Cameroon, Ghana, Nigeria, Togo) through Central and Eastern Africa (Democratic Republic of the Congo, western Ethiopia, Kenya, South Sudan, Tanzania, Uganda). It is found across much of Southern Africa, in a wide array of habitats, with some of the species' densest populations being in Angola, Botswana, Eswatini, Malawi, Mozambique, Namibia, South Africa, Zambia and Zimbabwe.

Habitat