Western green mamba
Encyclopedia
The Western green mamba (Dendroaspis viridis), or also known as the West African green mamba or Hallowell's green mamba, is a long, thin and highly venomous arboreal snake of the family Elapidae
.
and occurs in southern Senegal
, Gambia
, Guinea-Bissau
, Guinea
, Sierra Leone
, Liberia
, Côte d’Ivoire, Ghana
, Togo
, Benin
, and southwest Nigeria
. It can also be found in the very southern tip of Mali
along the border with Côte d’Ivoire, western Cameroon
and Gabon
.
, thicket, and woodland regions of western Africa. Although mainly found in dense and closed forests, these snakes can persist in areas where the tree cover has been removed, providing that sufficient hedges and thicket remain. In areas where there is very severe encroachment on their natural habitat or areas where vegetation or trees have been destroyed, these snakes will go into suitably vegetated city suburbs and towns often dwelling in the thickets of bushes or atop lush trees in parks and other well vegetated areas.
, but larger than the Eastern green mamba
the Western green mamba is a long and very slender bodied snake with a long tapering tail. It is the largest of the arboreal mamba's. The average length of an adult snake of this species is between 1.8 metres (5.9 ft) and 2.2 metres (7.2 ft). Most are around 1.8 metres (5.9 ft), but specimens measuring around 2 metres (6.6 ft) are quite common also. Some specimens of this species can grow to lengths of 3.2 metres (10.5 ft), which is the maximum for this snake. The head is narrow and elongate, with a distinct canthus and slightly distinct from the neck. On rare occasions the neck may be flattened when the snake is aroused, but there is no hood. Eyes are medium in size with round pupils and a yellow brown iris. Although the vast majority of specimens are greenish-yellow, olive green, or emerald green in colour, some specimens have shown different colouration. Although very rare, light blue or full yellow specimens do occur. The scales of the body of this species have a black edging. The dorsal scales of this snake are oblique, smooth, narrow, and exceptionally large for an elapid.
s, including rodents such as mice
, rat
s, and squirrels
. Other mammals include bats
, tree pangolins
, and shrew
s. They also feed on lizard
s, frog
s, and bird eggs. This snake actively pursues its prey, striking rapidly and often until the prey succumbs to the venom.
(Dendroaspis) family, but differs from other mamba's in toxicity or even the mixture of toxins in the venom at times. The venom consists mainly of neurotoxin
s, cardiotoxins, and fasciculins. The SC
for this species is 0.7 mg/kg and the average venom yield per bite is approximately 100 mg. Human fatalities as a result of bites from this species are rare due to the fact that this species does not often cross paths with humans, but bites have occurred and many of the recorded bites have been fatal. The mortality rate of untreated bites is not exactly known, but is said to be quite high (probably somewhere between 50%-70% as an educated guess according to Ernst and Zug et al. 1996). When bitten, symptoms rapidly begin to manifest, usually within the first 15 minutes or less. Common symptoms of a bite from a Western green mamba include local pain and swelling, although uncommon, local necrosis can be moderate, ataxia
, headache, drowsiness, difficulty breathing, vertigo
, hypotension (low blood pressure), diarrhea, dizziness, and paralysis. Left untreated, new and more severe symptoms begin to manifest. All symptoms worsen and the victim eventually dies due to suffocation resulting from paralysis of the respiratory muscles. Depending on the nature and severity of a bite, death can occur in as fast as an hour but usually it takes 2-4 hours before an untreated victim dies.
(Dendroaspis angusticeps), the Black mamba
(Dendroaspis polylepis), and the Jameson's mamba (Dendroaspis jamesoni) which has two subspecies: Jameson's green mamba (Dendroaspis jamesoni jamesoni) and Jameson's black-tail mamba (Dendroaspis jamesoni kaimosea).
Elapidae
Elapidae is a family of venomous snakes found in tropical and subtropical regions around the world, terrestrially in Asia, Australia, Africa, North America and South America and aquatically in the Pacific and Indian Oceans...
.
Geographic range
The Western green mamba is native to West AfricaWest Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
and occurs in southern Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
, Gambia
The Gambia
The Republic of The Gambia, commonly referred to as The Gambia, or Gambia , is a country in West Africa. Gambia is the smallest country on mainland Africa, surrounded by Senegal except for a short coastline on the Atlantic Ocean in the west....
, Guinea-Bissau
Guinea-Bissau
The Republic of Guinea-Bissau is a country in West Africa. It is bordered by Senegal to the north, and Guinea to the south and east, with the Atlantic Ocean to its west....
, Guinea
Guinea
Guinea , officially the Republic of Guinea , is a country in West Africa. Formerly known as French Guinea , it is today sometimes called Guinea-Conakry to distinguish it from its neighbour Guinea-Bissau. Guinea is divided into eight administrative regions and subdivided into thirty-three prefectures...
, Sierra Leone
Sierra Leone
Sierra Leone , officially the Republic of Sierra Leone, is a country in West Africa. It is bordered by Guinea to the north and east, Liberia to the southeast, and the Atlantic Ocean to the west and southwest. Sierra Leone covers a total area of and has an estimated population between 5.4 and 6.4...
, Liberia
Liberia
Liberia , officially the Republic of Liberia, is a country in West Africa. It is bordered by Sierra Leone on the west, Guinea on the north and Côte d'Ivoire on the east. Liberia's coastline is composed of mostly mangrove forests while the more sparsely populated inland consists of forests that open...
, Côte d’Ivoire, Ghana
Ghana
Ghana , officially the Republic of Ghana, is a country located in West Africa. It is bordered by Côte d'Ivoire to the west, Burkina Faso to the north, Togo to the east, and the Gulf of Guinea to the south...
, Togo
Togo
Togo, officially the Togolese Republic , is a country in West Africa bordered by Ghana to the west, Benin to the east and Burkina Faso to the north. It extends south to the Gulf of Guinea, on which the capital Lomé is located. Togo covers an area of approximately with a population of approximately...
, Benin
Benin
Benin , officially the Republic of Benin, is a country in West Africa. It borders Togo to the west, Nigeria to the east and Burkina Faso and Niger to the north. Its small southern coastline on the Bight of Benin is where a majority of the population is located...
, and southwest Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
. It can also be found in the very southern tip of Mali
Mali
Mali , officially the Republic of Mali , is a landlocked country in Western Africa. Mali borders Algeria on the north, Niger on the east, Burkina Faso and the Côte d'Ivoire on the south, Guinea on the south-west, and Senegal and Mauritania on the west. Its size is just over 1,240,000 km² with...
along the border with Côte d’Ivoire, western Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
and Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...
.
Habitat
Western green mamba's live mainly in the coastal tropical rainforestRainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
, thicket, and woodland regions of western Africa. Although mainly found in dense and closed forests, these snakes can persist in areas where the tree cover has been removed, providing that sufficient hedges and thicket remain. In areas where there is very severe encroachment on their natural habitat or areas where vegetation or trees have been destroyed, these snakes will go into suitably vegetated city suburbs and towns often dwelling in the thickets of bushes or atop lush trees in parks and other well vegetated areas.
Description
Smaller than the Black mambaBlack mamba
The black mamba , also called the common black mamba or black-mouthed mamba, is the longest venomous snake in Africa, averaging around in length, and sometimes growing to lengths of...
, but larger than the Eastern green mamba
Eastern green mamba
The Eastern green mamba is a medium to large arboreal highly venomous snake of the family Elapidae.-Description:...
the Western green mamba is a long and very slender bodied snake with a long tapering tail. It is the largest of the arboreal mamba's. The average length of an adult snake of this species is between 1.8 metres (5.9 ft) and 2.2 metres (7.2 ft). Most are around 1.8 metres (5.9 ft), but specimens measuring around 2 metres (6.6 ft) are quite common also. Some specimens of this species can grow to lengths of 3.2 metres (10.5 ft), which is the maximum for this snake. The head is narrow and elongate, with a distinct canthus and slightly distinct from the neck. On rare occasions the neck may be flattened when the snake is aroused, but there is no hood. Eyes are medium in size with round pupils and a yellow brown iris. Although the vast majority of specimens are greenish-yellow, olive green, or emerald green in colour, some specimens have shown different colouration. Although very rare, light blue or full yellow specimens do occur. The scales of the body of this species have a black edging. The dorsal scales of this snake are oblique, smooth, narrow, and exceptionally large for an elapid.
Scalation
Dorsal scales at mid-body 13, ventrals 211-225, subcaudals 107-120, subcaudals are paired, anal plate is divided, upper labials 7-9, pre-oculars 3, post-oculars 3-4, lower labials 8-10, temporals 2+1 variable.Behavior, Prey, and Predators
This species is mostly diurnal, but may be active at night as well. It is an arboreal snake, but it does commonly go to the ground. In fact, it is equally at home hunting and feeding on prey on the ground or in trees. When it wants to sleep it seeks out tree branches that offer dense cover. It is a very quick, extremely agile, alert, and very aggressive and nervous snake. When confronted it will quickly attempt to escape (usually up a tree if possible) and avoid any sort of confrontation. If cornered, the Western green mamba is highly dangerous and will show a fearsome display of aggression, loudly hissing and striking repeatedly.Prey
The Western green mamba's natural prey consists mainly of birds and small mammalMammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, including rodents such as mice
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
, rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, and squirrels
Squirrel
Squirrels belong to a large family of small or medium-sized rodents called the Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots , flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and Africa and have been introduced to Australia...
. Other mammals include bats
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
, tree pangolins
Tree pangolin
The Tree Pangolin is one of eight extant species of pangolin and is native to equatorial Africa. Also known as the White-bellied Pangolin or Three-cusped Pangolin, it is the most common of the African forest pangolins.-Taxonomy:The Tree Pangolin belongs to the subgenus Phataginus and some...
, and shrew
Shrew
A shrew or shrew mouse is a small molelike mammal classified in the order Soricomorpha. True shrews are also not to be confused with West Indies shrews, treeshrews, otter shrews, or elephant shrews, which belong to different families or orders.Although its external appearance is generally that of...
s. They also feed on lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, and bird eggs. This snake actively pursues its prey, striking rapidly and often until the prey succumbs to the venom.
Predators
The Western green mamba has no natural predators, but humans and birds of prey are this snakes main threat.Venom
The Western green mamba's venom is similar to other members of the MambaMamba
Mambas, of the genus Dendroaspis , are a group of highly venomous, fast-moving land-dwelling snakes of Africa. They belong to the family of Elapidae which includes cobras, coral snakes, taipans, brown snakes, tiger snakes, death adders, kraits and, debatably, sea snakes...
(Dendroaspis) family, but differs from other mamba's in toxicity or even the mixture of toxins in the venom at times. The venom consists mainly of neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
s, cardiotoxins, and fasciculins. The SC
Subcutaneous injection
A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, collectively referred to as the...
for this species is 0.7 mg/kg and the average venom yield per bite is approximately 100 mg. Human fatalities as a result of bites from this species are rare due to the fact that this species does not often cross paths with humans, but bites have occurred and many of the recorded bites have been fatal. The mortality rate of untreated bites is not exactly known, but is said to be quite high (probably somewhere between 50%-70% as an educated guess according to Ernst and Zug et al. 1996). When bitten, symptoms rapidly begin to manifest, usually within the first 15 minutes or less. Common symptoms of a bite from a Western green mamba include local pain and swelling, although uncommon, local necrosis can be moderate, ataxia
Ataxia
Ataxia is a neurological sign and symptom that consists of gross lack of coordination of muscle movements. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum...
, headache, drowsiness, difficulty breathing, vertigo
Vertigo
Vertigo is a form of dizziness.Vertigo may also refer to:* Vertigo , a 1958 film by Alfred Hitchcock**Vertigo , its soundtrack** Vertigo effect, or Dolly zoom, a special effect in film, named after the movie...
, hypotension (low blood pressure), diarrhea, dizziness, and paralysis. Left untreated, new and more severe symptoms begin to manifest. All symptoms worsen and the victim eventually dies due to suffocation resulting from paralysis of the respiratory muscles. Depending on the nature and severity of a bite, death can occur in as fast as an hour but usually it takes 2-4 hours before an untreated victim dies.
Taxonomy
Three very close relatives of the Western green mamba (Dendroaspis viridis) are the Eastern green mambaEastern green mamba
The Eastern green mamba is a medium to large arboreal highly venomous snake of the family Elapidae.-Description:...
(Dendroaspis angusticeps), the Black mamba
Black mamba
The black mamba , also called the common black mamba or black-mouthed mamba, is the longest venomous snake in Africa, averaging around in length, and sometimes growing to lengths of...
(Dendroaspis polylepis), and the Jameson's mamba (Dendroaspis jamesoni) which has two subspecies: Jameson's green mamba (Dendroaspis jamesoni jamesoni) and Jameson's black-tail mamba (Dendroaspis jamesoni kaimosea).
External links
- Bushdrums.com - Green Mamba Video filmed in Gabon