Sites - Important Bird and Biodiversity Areas (IBAs)
email a friend
South Nandi forest
Kenya, Rift Valley Province
34o 59.88' East 0o 6.30' North
1,700 - 2,000m
Year of IBA assessment
Site description This area is a mid-elevation forest lying just west of Kapsabet town and south of the main Kapsabet–Kaimosi road. South Nandi was once contiguous with Kakamega forest (IBA KE058) and the two forests are still no more than a few kilometres apart at their closest points. Rainfall is high, 1,600–1,900 mm/year depending on altitude. The forest is drained by the Kimondi and Sirua rivers, which merge to form the Yala river flowing into Lake Victoria. The landscape is gently undulating and underlain by granitic and basement complex rocks, which weather to give deep, well-drained, moderately fertile soils. The South Nandi area has high agricultural potential and human densities around it are also high, particularly to the west. Biogeographically, South Nandi is often considered an eastern extension of Kakamega. However, it is higher in altitude than Kakamega and floristically less diverse. In effect, South 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. Common trees include Tabernaemontana stapfiana, Macaranga kilimandscharica, Croton megalocarpus, C. macrostachyus, Drypetes gerrardii, Celtis africana, Prunus africana, Neoboutonia macrocalyx and Albizia gummifera. South Nandi was gazetted in 1936 as a Trust Forest covering 20,200 ha, since when c.2,200 ha have been excised for settlement, c.340 ha planted with tea, and 1,400 ha planted with exotic tree species. Of the remaining area, at most c.13,000 ha is closed-canopy forest, the rest being scrub, grassland or cultivation.
Key Biodiversity See Box and Table 3 for key species. South Nandi forest is almost certainly the most important site in the world for the threatened Eremomela turneri. The area supports exceptionally high densities of this little-known species (around 0.27 groups/ha, equating to 1.1 birds/ha), and an estimated population of 13,000 birds. The avifauna (like that of North Nandi, IBA KE053) is mainly Afromontane, but with strong western affinities. There is so far no comprehensive bird list, but a survey in 1996 recorded 111 species of forest birds, including 47 forest specialists. Regionally threatened species include Stephanoaetus coronatus (uncommon resident), Glaucidium tephronotum (status unknown), Indicator conirostris (local and uncommon), Indicator exilis (local and uncommon), Kakamega poliothorax (scarce and very local), Sheppardia polioptera (local and uncommon), Dyaphorophyia concreta (scarce) and Hyliota australis (uncommon).
Non-bird biodiversity: The ungulate Tragelaphus eurycerus (LR/nt) is reported to occur, but there are no confirmed records.