Trends and population size of White-necked Rockfowl Picathartes gymnocephalus within the Nyamibe Bepo Forest Reserve in Ghana

Abstract

The White-necked Rockfowl Picathartes gymnocephalus (family Picathartidae) is endemic to the Upper Guinea forest and has a global population of <10 000 mature individuals. This species is listed as Vulnerable on the IUCN Red List owing to its declining population, mainly as a result of habitat fragmentation, degradation and predation within its range states. Previous studies showed that many nesting colonies of the species in Ghana have disappeared following extensive loss of forest cover. However, recent field visits identified nesting colonies in several forest reserves, including the Nyamibe Bepo Forest Reserve where a significant proportion of the species’ population in the country is reported to occur. This study investigated the population size of the White-necked Rockfowl in Nyamibe Bepo to compare the extent of the current nesting colonies to those documented in 2011. A survey of nesting sites in the Bronko area of the reserve returned a total of 54 nests distributed across 10 rock-faces, and 88 individuals. Compared with the 53 nests reported in 2011, this indicates a stable population over the past decade in this section of the reserve. In contrast, colonies within the Ashilvikrom and Amanokrom sections have declined significantly. Thus, this indicates an overall population decline of the species within the Nyamibe Bepo Forest Reserve. By hosting 3.3% of the global minimum population and 41 reproductive units of the Vulnerable White-necked Rockfowl, the Nyamibe Bepo Forest Reserve could qualify as an Important Bird Area (IBA) under criterion A1a and a Key Biodiversity Area (KBA) under criterion A1b. We advocate that further steps be taken to engage conservation organisations and the government for more-formal protection of the site for the conservation of this Vulnerable species.