Competition for food by expanding pipistrelle bat populations (Pipistrellus pipistrellus) might contribute to the decline of lesser horseshoe bats (Rhinolophus hipposideros).

摘要

Rhinolophus hipposideros has undergone a dramatic decline throughout much of western Europe from the 1960s. The mechanisms responsible for this phenomenon have not been conclusively identified. At the same time, some populations of P. pipistrellus have increased substantially, possibly as a consequence of foraging upon insects attracted by street lamps. To evaluate whether there might be some ecological link between the opposite demographic trends observed in the two species, the diets of two sympatric populations of R. hipposideros and P. pipistrellus in south-west Switzerland were compared. The 2 bat species fed upon the same categories of prey, mainly moths and Diptera, and interspecific differences in diet composition in spring when resourceswere most likely to be limiting were not recognized. Although using different foraging strategies, both species may visit the same or adjacent feeding grounds, therefore potentially competing for the same populations of prey.