Physical clutter affects the use of artificial ponds by the Lesser Bulldog Bat Noctilio albiventris (Chiroptera: Noctilionidae)

Abstract

Bats frequently feed over water bodies, but the net value of the water bodies depends on characteristics such as the amount of physical clutter the water body has. More physical clutter may reduce the detection of prey by bats and may also increase energetic costs by increasing in the number of obstacles to avoid. Consequently, we hypothesized that increasing physical clutter affected the use of an artificial pond where the Lesser Bulldog Bat Noctilio albiventris, a Neotropical fishing bat, forages regularly over water. We experimentally tested this idea recording the number of passes and feeding buzzes emitted by the bats on different nights when we added two levels of obstacles over the water and on control nights with no obstacles. We only found differences between the treatment with the highest obstacle density and the control; there were fewer passes and less feeding buzzes with more obstacles. Therefore, the addition of obstacles did affect the foraging behavior of N. albiventris. Furthermore, we suggest that increasing physical clutter, as in our experiments, may be a cost-effective way to reduce conflicts between local fisher farmers and fishing bats in Neotropical rural areas.

Keywords
Bats-humans conflict; Colombia; Echolocation; Fish-eating bats