Breeding and moult of four bird species in tropical West Africa

Abstract

The annual cycles of breeding and moult were studied in four species of birds in Liberia in tropical West Africa: Fiscal Shrike, Lanius collaris Linnaeus 1758; Vieillot's Black Weaver, Ploceus nigerrimus Vieillot 1819; Common Garden Bulbul, Pycnonotus barbatus (Destontaines 1789); and Little Greenbul, Andropadus virens Cassin 1857. Pronounced differences were observed. The insectivorous L. collaris reproduced during the wet season, with moult towards the end of the wet season. This species experienced significant weight loss during the dry season, when food was more scarce. In contrast, the omnivorous P. nigerrimus fed on rice during the dry season, with rapid moult and continuation of breeding during this time. Only male P. nigerrimus experienced significant weight loss during the dry season, possibly because of large energy expenditures associated with nest building. The omnivorous P. barbatus appeared to be non-seasonal in reproduction, with moult in the wet season. The omnivorous A. virens was non-seasonal in both breeding and moult. Thus, there were four different patterns of reproduction and moult among the four species: wet-season breeding/wet-season moult, L. collaris; non-seasonal breeding/dry-season moult, P. nigerrimus-, non-seasonal breeding/wet-season moult, P. barbatus; and non-seasonal breeding/non-seasonal moult, A. virens.

Key Words:

• birds
• breeding
• Liberia
• moult
• reproduction
• West Africa