Black Mamba

The black mamba (Dendroaspis polylepis) is a species of extremely venomous snake, a member of the family Elapidae 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 2 m (6 ft 7 in) and commonly grow to 3 m (9 ft 10 in). Specimens of 4.3 to 4.5 m (14 ft 1 in to 14 ft 9 in) have been reported. Its skin colour varies from grey to dark brown. Juvenile black mambas tend to be paler than adults and darken with age.

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 16 km/h (10 mph) for short distances. Adult black mambas have few natural predators.

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 eye.The adult snake's length typically ranges from 2 to 3 m (6 ft 7 in to 9 ft 10 in) but specimens have grown to lengths of 4.3 to 4.5 m (14 ft 1 in to 14 ft 9 in). It is the second-longest venomous snake species, exceeded in length only by the king cobra. The black mamba is a proteroglyphous (front-fanged) snake, with fangs up to 6.5 mm (0.26 in) in length,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.

The body mass of black mambas has been reported to be about 1.6 kg (3.5 lb), although a study of seven black mambas found an average weight of 1.03 kg (2.3 lb), ranging from 520 g (1.15 lb) for a specimen of 1.01 m (3 ft 4 in) total length to 2.4 kg (5.3 lb) for a specimen of 2.57 m (8 ft 5 in) total length.

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, Swaziland, Malawi, Zambia, Zimbabwe, Botswana, South Africa, Namibia, and Angola. The black mamba's distribution in parts of West Africa has been disputed.

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. The size of the black mamba and its ability to raise its head a large distance from the ground enables it to launch as much as 40% of its body length upwards, so mamba bites to humans can occur on the upper body. The black mamba's reputation for being ready to attack is exaggerated; it is usually provoked by perceived threats such as the blocking of its movements and ability to retreat. The species' reputed speed has also been exaggerated; it cannot move more quickly than 16 km/h (10 mph).

The black mamba's breeding season spans from September to February, following the drop in temperature which occurs from April to June. Rival males compete by wrestling, attempting to subdue each other by intertwining their bodies and wrestling with their necks. Some observers have mistaken this for courtship. During mating, the male will slither over the dorsal side of the female while flicking its tongue. The female will signal its readiness to mate by lifting its tail and staying still. The male will then coil itself around the posterior end of the female and align its tail ventrolaterally with the female's. Intromission may last longer than two hours and the pair remain motionless apart from occasional spasms from the male.

The black mamba usually hunts from a permanent lair, to which it will regularly return if there is no disturbance. It mostly preys on small vertebrates such as birds, particularly nestlings and fledglings, and small mammals like rodents, bats, hyraxes and bushbabies. They generally prefer warm-blooded prey but will also consume other snakes.

Adult mambas have few natural predators aside from birds of prey. Brown snake eagles are verified predators of adult black mambas, of up to at least 2.7 m (8 ft 10 in). 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 take a black mamba for prey.

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.

Unlike many venomous snake species, black mamba venom does not contain protease enzymes. Its bites do not generally cause local swelling or necrosis, and the only initial symptom may be a tingling sensation in the area of the bite. The snake tends to bite repeatedly and let go, so there can be multiple puncture wounds. Its bite can deliver about 100–120 mg of venom on average; the maximum recorded dose is 400 mg.

The venom is predominantly neurotoxic, and symptoms often become apparent within ten minutes. The venom of the black mamba is a protein of low molecular weight and as a result is able to spread rapidly within the bitten tissue. The venom of this species is rapid-acting.

Neurotoxicity is the dominant clinical feature and severe flaccid paralysis. Early neurological signs that indicate severe envenomation include a metallic taste, drooping eyelids (ptosis) and gradual symptoms of bulbar palsy. Other neurological symptoms include miosis, blurred or diminished vision, paresthesia, dysarthria, dysphagia, dyspnea, difficulty handling saliva, an absent gag reflex, fasciculations, ataxia, vertigo, drowsiness and loss of consciousness, and respiratory paralysis.

Standard first aid treatment for any suspected bite from a venomous snake is the application of a pressure bandage to the bite site, minimisation of movement of the victim and conveyance to a hospital or clinic as quickly as possible. The lethal, neurotoxic nature of black mamba venom means an arterial tourniquet may be of benefit.