Mamba


Mambas are fast moving venomous snakes of the genus Dendroaspis in the family Elapidae. Four extant species are recognised currently; three of those four species are essentially arboreal and green in colour, whereas the so-called black mamba, Dendroaspis polylepis, is largely terrestrial and generally brown or grey in colour. All are native to various regions in sub-Saharan Africa and all are feared throughout their ranges, especially the black mamba. In Africa there are many legends and stories about mambas.

Behaviour

The three green species of mambas are arboreal, whereas the black mamba is largely terrestrial.The black mamba is one of the largest and most venomous in Africa. All four species are active diurnal hunters, preying on birds, lizards, and small mammals. At nightfall some species, especially the terrestrial black mamba, shelter in a lair. A mamba may retain the same lair for years.
Mambas and cobras are in the same family: the Elapidae. Like cobras, a mamba may rear and form a hood as part of its threat display, but the mamba's hood is narrower and is longer than the broader hood of some species of cobra, such as say, the spectacled cobras of parts of Asia. In their threat display mambas commonly open their mouths; the black mamba's mouth is black within, which renders the threat more conspicuous. Typically also, a rearing mamba tends to lean well forward, instead of standing erect as a cobra does.
Stories of black mambas that chase and attack humans are common, but in fact the snakes generally avoid contact with humans. Most apparent cases of pursuit probably are examples of where witnesses have mistaken the snake's attempt to retreat to its lair when a human happens to be in the way. The black mamba usually uses its speed to escape from threats, and humans actually are their main predators, rather than prey.

Venom

All mambas are highly venomous. Their venoms consist mostly of neurotoxins. Besides the neurotoxins, they also carry cardiotoxins and fasciculins. Other components may include calcicludine, which is a known component of the eastern green mamba's venom and calciseptine, which is a component of black mamba venom. Toxicity of individual specimens within the same species and subspecies can vary greatly based on several factors, including geographical region. Even the weather and altitude can influence toxicity. A bite can be fatal to humans without access to proper first aid and subsequent antivenom treatment, as it shuts down the lungs and heart. The western green mamba, eastern green mamba, and Jameson's mamba possess venom similar in composition and effects to that of the black mamba. However, as their venoms are less toxic, and their temperaments generally not as aggressive or as explosive when provoked, and as none of the three injects as much venom as the black mamba, their bites are materially less dangerous.
Before antivenom was available, envenomations by mambas carried a high fatality rate. Untreated black mamba bites have a mortality rate of 100%, but presently, fatalities have become much rarer due to wide availability of antivenom.

Mamba toxins

Mamba toxin consists of several components, with different targets. Examples are:
Dendroaspis, derives from Ancient Greek déndron, meaning "tree", and aspis, which is understood to mean "shield", but also denotes "cobra" or simply "snake", in particular "snake with hood ". Via Latin aspis, it is the source of the English word "asp". In ancient texts, aspis or asp often referred to the Egyptian cobra, in reference to its shield-like hood. Thus, "Dendroaspis" literally means tree asp, reflecting the arboreal nature of most of the species within the genus. The genus was first described by the German ornithologist and herpetologist Hermann Schlegel in 1848. Evidence suggests that Dendroaspis, Ophiophagus, Bungarus, and Hemibungarus form a solid non-coral snake Afro-Asiatic clade.
Of the currently recognized mamba species, three are green and the other is the "black mamba", so called in spite of its generally brown or grey body.

Range and characteristics

Black mambas live in the savannas and rocky hills of southern and eastern Africa. They are Africa's longest venomous snake, reaching up to 14 feet in length, although 8.2 feet is more the average. They are also among the fastest snakes in the world, slithering at speeds of up to 12.5 miles per hour.
SpeciesAuthorityImageSubsp.*Common nameGeographic range
Dendroaspis angusticepsT0Eastern green mambaFound in Kenya, Tanzania, Malawi, Mozambique, Zimbabwe, Swaziland, eastern South Africa, Democratic Republic of the Congo, South Sudan, Sudan, Niger, Central African Republic, Chad
Dendroaspis jamesoni2Jameson's mambaFound in Central Africa in Sudan, Gabon, Angola, Zambia, Republic of the Congo, Cameroon, Nigeria, Kenya, Uganda, Rwanda, Central African Republic, Benin, Ghana
Dendroaspis polylepisGünther, 18640Black mambaFound in eastern Africa and southern Africa in northeast Democratic Republic of the Congo, southwestern Sudan to Ethiopia, Eritrea, Somalia, Kenya, eastern Uganda, Tanzania, southwards to Mozambique, Swaziland, Malawi, Zambia, Zimbabwe, Lesotho, Rwanda, Djibouti and Botswana to KwaZulu-Natal in South Africa, and Namibia; then northeasterly through Angola to the southeastern part of the Democratic Republic of Congo
Dendroaspis viridis0Western green mambaFound only in western Africa in southern Senegal, Gambia, Guinea-Bissau, Guinea, Sierra Leone, Liberia, Côte d’Ivoire, Ghana, Togo, Benin, and southwest Nigeria

* Including the nominate subspecies.
T Type species.