Short-Term Behavioural Response Of Granivorous Birds To Food Augmentation Under Different Microhabitats
AbstractFood is a potential limiting resource for birds, which often influences their population through effects on behaviour, survival and reproduction. This may oblige birds to modify their foraging behaviour when food density varies in order to forage optimally. Foraging theory predicts that an optimal forager should abandon a patch when its resource is augmented. That is foraging activity should be reduced when food is abundant. This
study therefore aimed at determining the response of granivorous birds to different food densities in two different patch environments within the International Institute for Tropical Agriculture (IITA). Granivorous birds were provided with millet seeds in open and covered food patches during an experimental period that lasted two weeks in the dry season (February and March) of 2008. The patches were replicated in three sites. Five grammes of food were given for the first week and food was augmented with additional 5g making 10g of food for the second week. Giving-up density (GUD= amount of food left after foraging in a patch) was used to
test the response of granivorous birds to different food abundance. Findings indicated a positive response to food augmentation (p<0.002) as GUD increased regardless of the patch. GUD was particularly higher in the
patches (open and covered patches) of the forest site thus underlining the quality of the site. The site also had the most number of bird species which further gave credence to its quality. This result gives an insight into the likely behaviour of birds in response to their changing habitats especially in this period of global climate change. Future studies of this type could be instrumental in the assessment and monitoring of fluctuating and degraded habitats.