The black mamba (Dendroaspis polylepis) is a species of highly venomous snake belonging to the family Elapidae. It is native to parts of sub-Saharan Africa. First formally described by Albert Günther in 1864, it is the second-longest venomous snake after the king cobra; mature specimens generally exceed and commonly grow to . Specimens of have been reported. It varies in colour from grey to dark brown. Juvenile black mambas tend to be more pale in colour than adults, and darken with age. Despite the common name, the black mamba is not black; the colour name describes rather the inside of its mouth, which it displays when feeling threatened.
The species is both terrestrial (ground-living) and arboreal (tree-living); it inhabits savannah, woodland, rocky slopes and in some regions, dense forest. It is diurnal and is known to prey on birds and small mammals. Over suitable surfaces, it can move at speeds up to for short distances. Adult black mambas have few natural predators.
In a threat display, the black mamba usually opens its inky-black mouth, spreads its narrow neck-flap and sometimes hisses. It is capable of striking at considerable range and may deliver a series of bites in rapid succession. Its venom is primarily composed of neurotoxins that often induce symptoms within ten minutes, and is frequently fatal unless antivenom is administered. Despite its reputation as a formidable and highly aggressive species, the black mamba attacks humans only if it is threatened or cornered. It is rated as least concern on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species.
Taxonomy
The first formal description of the black mamba was made in 1864 by German-born British zoologist Albert Günther. This specimen is the holotype and is housed in the Natural History Museum, London. The term "mamba" is derived from the Zulu word "imamba". In Tanzania, a local Ngindo name is ndemalunyayo ("grass-cutter") because it supposedly clips grass.
In 1873, German naturalist Wilhelm Peters described Dendraspis antinorii from a specimen in the museum of Genoa that had been collected by Italian explorer Orazio Antinori in what is now northern Eritrea. This was subsequently regarded as a subspecies a lumping diagnosis that remained in force until 1946 when South African herpetologist Vivian FitzSimons again split them into separate species.
Description
thumb|The black interior of the mouth of a black mamba
The black mamba is a long, slender, cylindrical snake. It has a coffin-shaped head with a somewhat pronounced brow ridge and a medium-sized eyes. and the second-longest venomous snake species overall, exceeded in length only by the king cobra. located at the front of the maxilla. The tail of the species is long and thin, the caudal vertebrae making up 17–25% of its body length.
Specimens vary considerably in colour, including olive, yellowish-brown, khaki and gunmetal but are rarely black. The scales of some individuals may have a purplish sheen. Individuals occasionally display dark mottling towards the posterior, which may appear in the form of diagonal crossbands. Black mambas have greyish-white underbellies. The common name is derived from the appearance of the inside of the mouth, dark bluish-grey to nearly black. Mamba eyes range between greyish-brown and shades of black; the pupil is surrounded by a silvery-white or yellow colour. Juvenile snakes are lighter in colour than adults; these are typically grey or olive green and darken as they age. The black mamba has between 23 and 25 rows of dorsal scales at midbody, 248 to 281 ventral scales, 109 to 132 divided subcaudal scales, and a divided anal scale. Its mouth is lined with 7–8 supralabial scales above, with the fourth and sometimes also the third one located under the eye, and 10-14 sublabial scales below. Its eyes have 3 or occasionally 4 preocular and 2–5 postocular scales.
Distribution and habitat
thumb|Juvenile in a tree, [[Kruger National Park, South Africa]]
The black mamba inhabits a wide range in sub-Saharan Africa; its range includes Burkina Faso, Cameroon, Central African Republic, Democratic Republic of the Congo, South Sudan, Ethiopia, Eritrea, Somalia, Kenya, Uganda, Tanzania, Burundi, Rwanda, Mozambique, Eswatini, Malawi, Zambia, Zimbabwe, Botswana, South Africa, Namibia, and Angola. The black mamba's distribution in parts of West Africa has been disputed. In 1954, the black mamba was recorded in the Dakar region of Senegal. This observation, and a subsequent observation that identified a second specimen in the region in 1956, has not been confirmed and thus the snake's distribution in this area is inconclusive.
During the threat display, any sudden movement by the intruder may provoke the snake into performing a series of rapid strikes, leading to severe envenomation. They generally prefer warm-blooded prey but will also consume other snakes. In the Transvaal area of South Africa, almost all recorded prey was rather small, largely consisting of rodents and similarly sized small or juvenile mammals as well as passerine birds, estimated to weigh only 1.9–7.8% of the mamba's body mass. The black mamba does not typically hold onto its prey after biting; rather it releases its quarry and waits for it to succumb to paralysis and death before it is swallowed. The snake's potent digestive system has been recorded to fully digest prey in eight to ten hours. Other eagles known to hunt or at least consume grown black mambas include tawny eagles and martial eagles. Young snakes have been recorded as prey of the Cape file snake. Mongooses, which have some resistance to mamba venom and are often quick enough to evade a bite, will sometimes harass or take a black mamba for prey, and may pursue them in trees. The similarly predatory honey badger also has some resistance to mamba venom. The mechanism in both mammals is thought to be that their muscular nicotinic acetylcholine receptors do not bind snake alpha-neurotoxins. Young mambas in the Serengeti are known to fall prey to southern ground hornbills, marsh owls and hooded vultures.
Venom
The black mamba is the most feared snake in Africa because of its size, aggression, venom toxicity and speed of onset of symptoms following envenomation, and is classified as a snake of medical importance by the World Health Organization.