West Africa occupies an area in excess of 6,140,000 km2, or approximately one-fifth of Africa. The majority of this land is plains that sit less than 300 meters above sea level. There are isolated high points many countries along the southern shore of West Africa.
The northern section of West Africa is composed of semi-arid terrain known as Sahel. The Sahel is mostly covered in grassland and savanna, with areas of woodland and shrubland between the Sahara and the savannahs of the western Sudan. Forests lay between the savannas and the southern coast upto 240 km in width.
Habitat diversity in Western Africa ranges from semidesert and savanna to tropical forests, mangroves, freshwater lakes and rivers, and wetlands. The Upper Guinea forest, extending from western Ghana through the Ivory Coast, Liberia, and Guinea to Southern Sierra Leone, is a biologically unique system that is considered one of the world’s priority conservation areas because of its high endemism. (Conservation International, 1999). Nearly 2000 plants and over 41 mammals are unique to the ecosystem. Species diversity is also high, with more than 20,000 butterfly and moth species, 15 species of even-toed ungulates, and 11 species of primates.