A Comparison of Foraging Site Characteristics of Two African Resident Insectivorous Birds in a Burned Habitat

Abstract

Detailed investigation of the foraging site utilised by avian species may reveal the habitat factors important in their conservation. This study compared the foraging sites of the Sunlark, Galerida modesta and Familiar Chart, Cercomela familiaris (both African resident insectivorous birds) a week after fire engulfed about one third of the 300 ha of the Amurum Forest Reserve, Nigeria. Foraging sites were compared based on proxies of food availability (ant, grasshopper and other insect abundance) and vegetation structure. Data on food availability and vegetation structures were obtained by quadrate sampling while foraging spots were determined from four stratified transects each surveyed four times during the study. Food availability was not a significant predictor of foraging site characteristics between the two bird species. However of the nine vegetation variables measured, grass height and proportion of burned grass cover per foraging site significantly distinguished the foraging sites of the two bird species; Sunlark foraged more at sites with shorter grasses and high proportion of burned grass cover as compared to the Familiar Chat. The characteristics of the foraging sites observed might have implications on the foraging success of the birds in line with literature on the Influences of vegetation structure on avian foraging behaviour.

Key words: Foraging site, Insectivorous birds, Burn, Vegetation structure, Food availability