Fig. 4.55 Dendroaspis sp.

Distribution

Sub-Saharan Africa. See link "Distribution" at the top of the page for detailed information.

  Map 25 Dendroaspis spp.

Biology

Very slender and agile snakes. Head narrow and elongated and almost indistinct from the body. Exceptionally large venom fangs and quantity of venom in comparison to other elapids. Tail long and thin. Fully-grown animals around 2 m long. D. polylepis specimens of up to 4 m have been described.

Colouring green, sometimes with shades of yellow. The black mamba is darker, olive, olive-brown or brown-grey (young animals may also be green). Black edges to the scales in D. jamesoni and D. viridis. Dorsal scales of D. viridis are strikingly large. A distinguishing characteristic of the black mamba is the blue-grey to black colour of the interior of its mouth.

D. angusticeps, D. jamesoni and D. viridis are predominantly tree- and bush-dwellers. D. polylepis can also climb but is usually found on the ground. D. jamesoni and D. viridis are typical rainforest-dwellers. D. angusticeps inhabits forest and scrubby areas, while D. polylepis is found in bushland (not over 1,500 m). D. polylepis is the most widespread of the species, and its natural habitat coincides with that of humans over large areas. Individuals have been known to inhabit the same lair in abandoned termite mounds, burrows or hollow tree trunks over periods of years.

When they encounter humans, mambas try to retreat as quickly as possible, which is seldom a problem for the arboreal species. The black mamba also tries to escape if at all possible, but displays increased aggression during the breeding season. If threatened, the black mamba will raise its head from the ground, with slightly flattened neck and open mouth, so that the black interior can be seen. It also emits a hollow-sounding hiss. The mamba is extremely agitated when in this state and is prepared to strike aggressively and repeatedly.

Risk

The most dangerous species is D. polylepis. The potency of its venom and the large amounts it can deliver as well as its aggressiveness have given it the reputation of being the most dangerous snake in Africa. Mamba envenoming must be treated extremely seriously and is quite often fatal (Christensen 1980). However, mambas are only rarely the cause of snakebites in Africa in comparison to other venomous snakes (Warrell 1980, Stahel 1980). 

Literature (biological)

Broadley 1983, Brodley and Cock 1989, Doucet 1963, Leloup 1960, Pitman 1974, Roman 1980, Villiers 1975, Visser and Chapman 1978, Welch 1982, O'Shea 2005