A total of 390 bird species are known to occur in the Korup National Park (KNP) and the surrounding Korup Project Area (KPA). Although the avifauna of KNP is incompletely known, it is already among the most ornithologically diverse lowland forest sites i n Africa. The avian diversity of the KPA is increased by the montane forest bird species of the Rumpi Hills Forest Reserve (RHFR) and the Nta Ali Forest Reserve (NAFR). The lowland and montane forests of the KNP/KPA are very important to the conservation of African forest birds. Four species found in the Korup area are considered globally threatened, and four are considered near-threatened. In addition, 40 species were considered for threatened status, some of which are likely future additions to the threatened list. Twelve of Korup's 36 montane forest bird species are endemic to the montane areas of western Cameroon, eastern Nigeria, and Bioko (Fernando Po). The RHFR is especially important as a refuge for montane birds because much of the montane forest elsewhere in western Cameroon has been cleared for agriculture. Breeding phenology data are provided for many lowland forest species. Additionally, this report provides information on many rarely recorded species for western Cameroon, including several species not previously documented in the region. Kemp's Longbill Macrosphenus ketnpi was recorded for the first time in Cameroon. Because it is sympatric with the Yellow Longbill M. flavicans in Korup, additional evidence now exists for the contention that M. ketnpi and M.flavicans are separate species. The Yellow-chested Apalis Apalisflavidawas also documented for the first time in Cameroon.