Common names: West African gaboon viper.

Bitis gabonica rhinoceros is a venomous

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 viper

Viperinae

The Viperinae, or viperines, are a subfamily of venomous vipers found in Europe, Asia and Africa. They are distinguished by their lack of the heat-sensing pit organs that characterize their sister group, the Crotalinae. Currently, 12 genera and 66 species are recognized...

 subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 found in West Africa

West 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:...

. It is distinguished from the nominate subspecies primarily by the presence of a set of large nasal horns.

Description

B. g. rhinoceros has a distinctive set of enlarged nasal scales that look like a pair of horns on its nose. This is a characteristic that it shares with a close relative, B. nascornis

Bitis nasicornis

Bitis nasicornis is a venomous viper species found in the forests of West and Central Africa. A big viper known for its striking color pattern and prominent horns on its nose. No subspecies are recognized.-Description:...

. However, B. nasicornis has a brighter color pattern and a narrower head. B. g. gabonica has no such enlarged nasal horns, and is overall somewhat smaller than B. g. rhinoceros. Also, with B. g. gabonica, the dark triangular marking leading back from the eye towards the angle of the mouth is divided. With B. g. rhinoceros it is not.

Geographic range

West Africa

West 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:...

 from 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...

 west to 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...

, including 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...

 and Ivory Coast. 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...

 is also mentioned.

According to Spawls & Branch (1995), Ghana and Togo are at the eastern limit of the range of this subspecies, and they begin to intergrade here with B. g. gabonica. The distribution map they provide indicates that the general range for B. g. rhinoceros does not include Togo, but that there has been at least one report of a specimen found there. Togo, together with 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 at least eastern Ghana, are part of a larger region known as the Dahomey Gap

Dahomey Gap

In West Africa, the Dahomey Gap refers to the portion of the Guinean forest-savanna mosaic that extends all the way to the coast in Benin, Togo and Ghana, thus separating the forest zone that covers much of the south of the region into two separate parts...

; a relatively dry region that separates the rainforests of West Africa from those of Central Africa.