THE INFLUENCE OF TIME OF DAY AND ENVIRONMENTAL-CONDITIONS ON THE FORAGING BEHAVIORS OF WILLIE WAGTAILS, RHIPIDURA LEUCOPHRYS

The insectivorous willie wagtail, Rhipidura leucophrys, exhibits a ran ge of discrete, easily identified foraging behaviours that include wag ging the tail and flashing the wing. We investigated whether wagtails adjust these, and other foraging behaviours, according to the time of day and environmental conditions. The rates of tail-wagging and wing-f lashing were influenced by the time of day and light intensity. Tail-w agging was more frequent at the start and end of the day, while wing f lashing was more frequent during the middle of the day. The rate of ae rial prey captures was also highest during the middle of the day and l ower in the early morning and late afternoon. These daily patterns of foraging behaviours correspond with the patterns of insect activity, w hich was greater in the middle of the day than in the early morning or late afternoon. The field data, together with experiments using a mod el wagtail tail, support the view that tail-wagging and wing-flashing an used to flush insect prey.