A twelve-month field study of the West African Thrush <i>Turdus pelios</i> (Passeriformes: Muscicapidae). Part 2: annual cycles

Abstract

In Africa, birds inhabiting forested regions are less seasonal in their activities than those from open
areas. In order to study annual cycles in forest regions of South western Nigeria, West African Thrushes (Turdus
pelios) were mist-netted and banded during the last two weeks of each month. The nest is a cup-shaped structure
built out of grasses, herbs, weeds, roots and earth laid out in a clockwise manner. Only the nesting tree and feeding
sites were defended during the breeding period. The clutch size was 2.69 ± 0.20 eggs with a mean incubation
period of 14.11 ± 0.26 days. The mean nestling period was 15 ± 1.00 days. The nestlings were fed on a variety of
plant and animal matter, of which grass seeds and insects were predominant. Moult was found to be protracted
with a population moult period of 194 days and a much shorter individual moult period. Moult and breeding
periods were spread out: moult period dovetailed into the breeding period. The birds were found to gain weight
during the period but they attained their maximum weight in August after the moult period. The lowest weight
was recorded in February, during the peak of the dry season, when food availability was lower.