Differences in the foraging behaviour of male and female Egyptian fruit bats (Rousettus aegyptiacus)

Abstract

Male and female animals frequently have different foraging behaviours owing to differences in body size or nutritional demand, or to intraspecific competition. We studied foraging by Egyptian fruit bats ( Rousettus aegyptiacus (E. Geoffroy, 1810)) in Cape Town, South Africa, to test predictions based on differences in nutritional demand during reproduction. Using radiotelemetry, we compared emergence, return, and foraging times of males and females during pregnancy and lactation. We also determined home-range size, habitat use, and use of figs (genus Ficus L.), which are a potential source of calcium for lactating females. During the pregnancy period, males left their roost later than females and were away from the roost for shorter periods. There were no differences in timing of foraging during lactation. Females foraged in native forest more than males did, but home-range size did not differ. There was no evidence that females fed on figs more than males did. Differences in foraging behaviour were not as predicted based on nutritional and energetic differences. The small population may have meant that there was little competition for food, and figs may have provided a profitable source of energy for both males and females. Differences in the timing of foraging are best explained by the need for males to defend roosting sites.