Kakamega Forest is a mid-altitude tropical rainforest, the easternmost outlier of the Congo Basin forests. Its West African affinities are unique in Kenya, and the forest contains many species found nowhere else in the country. The forest lies in the Lake Victoria catchment, about 40 km north of Kisumu, and just east of the Nandi Escarpment that forms the edge of the central highlands. Kakamega forest was first gazetted as Trust Forest in 1933, and two small Nature Reserves, Yala and Isecheno (totaling about 700 ha), were established within the Forest Reserve in 1967. In 1986, nearly 4,000 hectares of the northern portion of the forest, along with the adjacent 457 hectares Kisere Forest, were gazetted as a National Park, Kakamega Forest is an important catchment; the Isiukhu and Yala Rivers flow through the forest and gather tributaries from it. The terrain is undulating, with often steep-sided river valleys. The soils are well-drained, deep, heavily leached clay-loams and clays, of generally low fertility. Rainfall is approximately 2,001mm per year, decreasing from south to north, and apparently declining due to deforestation.
The forest holds large populations of Black-and-white Colobus (Colobus guereza) and Red-tailed Monkey (Cercopithecus ascanius schmidti), and small number of de brazza Monkey (Cercopithecus neglectus). Several West African forest mammals occur, such as Potto (Perodicticus potto), Giant Otter Shrew (Potamogale velox) and Lord Derby's Anomalure (Anomalurus derbianus). The small mammal community is also very rich and shows strong affinities to the Zaire basin. At least 28 snake species are recorded, including the rare Gold's Cobra (Pseudohaje goldii) and other West African species such as the Barred Green Snake (Philothamnus heterodermus carinatus), Black-lined Green Snake (Hapsidophrys lineata), Jameson's Mamba (Dendroaspis jamesoni kaimosae), Green Bush-viper (Atheris squamiger squamiger), Prickly Bush-viper (Atheris hispida) and Rhinoceros-horned Viper (Bitis nasicornis) (Spawls 1978). Two notable and probably endangered forest amphibians, Leptopelis modestus and Hyperolius lateralis, are recorded (Duff-MacKay 1980). The forest's butterfly fauna is very diverse and important, both regionally and continentally; around 350 species are thought to occur, including at least one endemic species, Metisella kakamega, and a near-endemic, Euphaedra rex (Larsen 1991). Kakamega's avifauna is unique not nationally, but continentally. Several species have isolated, relict populations here, including Ansorge's (Greenbul, Blue-headed Bee-eater, Chapin's Flycatcher and Turner's Eremomela, which are absent from all or nearly all of the superficially similar mid-elevation forests in Uganda. Chapin's Flycatcher is a restricted-range species characterizes the Kakamega and Nandi Forests Secondary Area, and is also present in the Albertine Rift Mountains Endemic Bird Area. The presence of the eremomela indicates biogeographic links to the Eastern Zaire Lowlands Endemic Bird Area. Kakamega itself has few endemic taxa; among birds, there is an endemic sub-species (kavirondensis) of Ansorge's Greenbul. At least 16 bird species occur in Kakamega but nowhere else in Kenya, and another 30 (such as the Grey Parrot) are probably now confined to this site. The grassy glades have their own distinctive avifauna, with many moist-grassland species that are now rare elsewhere in western Kenya. Kakamega has a rich diversity of trees, with common genera including Croton, Celtis, Trema, Antiaris, Bequaertiodendron and Zanthoxylum (Beentje 1990). Endemism is low, however, the only woody endemic being the liana Tiliacora kenyensis.
(vii), (ix) and (x): Kakamega forest has a unique presentation of avifauna with 16 species of bird found only here in Kenya; it is an important and significant natural habitat for conservation of avifauna as it currently provides a habitat for the highest number of forest-dependant bird species in Kenya. The undulating terrain with steep sided river valleys gives the forest its exceptional natural beauty and acts as/and is an important catchment for Isiukhu and Yala Rivers, its one of Kenya's top bird-watching destinations.
Kakamega forest was first gazetted as a Trust Forest in 1933, later on in 1986 a total of 4,000ha of the northern portion of the forest, along with the adjacent 457 ha of Kisere Forest, were amalgamated and gazetted as Kakamega National Park.
Kakamega is a complex and fragmented forest, and one that has been under attack, from inside and out, for many years. Logging for commercially valuable timber, and clear-felling of indigenous forest to make way for plantations, was extensive under the colonial Forest Service and continued until the late 1980s. This began the process of isolating the northern and southern blocks. Excisions for settlement, schools and tea plantations (the 'Nyayo Tea Zones') have claimed additional chunks of the forest. Kakamega District is one of the most densely populated in Kenya, and human pressure on the forest is extremely intense. Local people are estimated to derive products worth 100 million Kenya Shillings (approximately US$ 1.7 million) from the forest each year (Emerton 1994). To reduce the level of poaching for forest products in the forest KWS has developed a participatory forest management approach that incorporates the community in conservation initiatives.
Kakamega forest can be compared to Kibale and Mabira forests in Uganda, as they have the same species diversity and are an important bird area. We propose for the serial listing of Kakamega forest with similar forests in Uganda like Kibale, Mathira forests that as they have similar characteristics in terms of species diversity and signify the end of Congo basin forests. The Kakamega Forest is very unique to Kenya and has attracted a lot of international researchers into the area.