Foraging Movements of Epauletted Fruit Bats (Pteropodidae) in Relation to the Distribution of Sycamore Figs (Moraceae) in Kruger National Park, South Africa

Abstract

We examined the distribution of Ficus sycomorus in relation to the movements and feeding, behavior of two species of epauletted fruit bats in Kruger National Park in order to learn about the scale and tempo of the seed dispersal of this riparian tree. Radio-tagged Epomophorus crypturus and Epomophorus wahlbergi restricted > 90% of activity within riparian forests having F. sycomorus present; whereas, < 10% of activity occurred in thorn thickets where folivory on Balanites maughamii and frugivory on Sclerocarya birrea appeared to offer secondary sources of forage. Bats usually carried figs to foliage perches within 200 m of the fruiting tree before feeding. Within a night, maximum one-way movement was 13.9 km as bats visited ≤ four foraging patches. No significant difference occurred between foraging ranges of E. wahlbergi at Skukuza (16.0 ± 3.0 ha) and E. crypturus at Shingwedzi (19.9 ± 5.1 ha). However, E. crypturus at Babalala had significantly larger mean foraging range (52.4 ha ± 4.5 ha) than either species elsewhere. Mean foraging range, core use area, and long axis across foraging range of E. wahlbergi changed significantly with season, year, and fig abundance. Our study suggests interdependence between F. sycomorus and the two species of fruit bats in Kruger National Park with bat movements largely following the distribution of available ripe figs.