This area is a strip of high-canopy forest on the edge of the Nandi escarpment, above and immediately east of Kakamega forest (IBA KE058). North Nandi stretches for more than 30 km north to south and is 3–5 km wide for most of its length. Drainage is mainly eastwards into the Kigwal and Kimondi river systems, which flow through the South Nandi forest (KE055) and westwards into the Yala river and Lake Victoria. Biogeographically, North Nandi is transitional between the lowland forests of West and Central Africa (the easternmost outlier of which is Kakamega) and the montane forests of the central Kenya highlands. It is higher in altitude than Kakamega and the vegetation is floristically less diverse. Common trees include Diospyros abyssinica, Croton macrostachyus, Syzgium guineense and Celtis africana, with a denseundergrowth of Acanthus and Brillantaisia. Rainfall is c.1,500 mm annually, and the well-drained, friable soils are moderately fertile. North Nandi was first gazetted in 1936 as a Trust Forest covering 11,850 ha. In 1968 the North Nandi Nature Reserve was established, amounting to 3,434 ha. Since gazettement, a total of 1,343 ha have been excised, including part of the nature reserve. An additional 410 ha has been converted to Nyayo Tea Zone. Of the present gazetted forest area (10,500 ha), c.8,000 ha is indigenous, closed-canopy forest, the remainder consisting of cultivation, scrub, grassland, plantations and tea. All areas outside the nature reserve were originally slated for conversion to plantation forest, but this has not taken place.
See Box and Tables 2 and 3 for key species. The forest belongs to the Kakamega and Nandi forests Secondary Area of endemism, defined by the presence of the globally threatened, restricted-range Muscicapa lendu (a scarce resident). The avifauna is similar to that of Kakamega forest, being a mixture of species characteristic of two biomes: the Guinea–Congo Forests and Afrotropical Highlands biomes (34 out of 70 species in this latter biome are present). Around 160 species in all are recorded. North Nandi is less rich in species than Kakamega and its bird communities have a larger montane element. There have been no recent surveys here and the present status of North Nandi’s rare birds, including Muscicapa lendu, is unknown. Regionally-threatened species include Bostrychia olivacea (possibly locally extinct), Stephanoaetus coronatus (resident in small numbers), Glaucidium tephronotum (uncommon), Indicator conirostris (local and uncommon), Indicator exilis (local and uncommon), Kakamega poliothorax (scarce), Hyliota australis (uncommon) and Dyaphorophyia concreta (uncommon).
Non-bird biodiversity: None known to BirdLife International.
Pressure/threats to key biodiversity
North Nandi is an unusual and important forest. It contains many bird species that have very limited ranges in Kenya: a number occur only here and in Kakamega. Conversion of the forest to plantations, as originally envisaged, has fortunately not taken place. However, the forest remains a relatively narrow strip, under severe pressure from illegal timber extraction, charcoal burning, forest grazing of livestock, and unsustainable removal of forest products (firewood, honey and medicinal plants). There appears to have been no special protection of the nature reserve. Much encroachment and clearance has taken place on the western edge of the forest, especially since 1982. Because the forest boundaries are unclear this has been difficult for Forest Department staff to control. The forest’s shape, with a high perimeter-to-area ratio, means that edge effects are likely to be substantial. The Forestry Department is inadequately equipped to protect and manage the reserve, and its capacity urgently needs to be increased. Biological surveys were carried out here in the 1970s but there is little up-to-date information on the avifauna. The status and habitat requirements of Muscicapa lendu in particular need to be assessed.