Spatial organization of roosting in the insectivorous tropical bat Hipposideros speoris

Abstract

The roost organization of the insectivorous bat Hipposideros speoris was studied both in the field and in conditions of captivity. All the individuals roost singly and maintain a marked fidelity to their roost sites for long periods. The males use their urine as an olfactory cue in relocating their respective roost sites but the females appear to relocate their roost sites relatively by recognizing the position of neighbouring conspecifics. In captivity all the individuals prefer to roost in darker regions of the cage, which resulted in the formation of a hierarchical order of roosting. Experiments with captive bats revealed a greater ability to reorientate towards their roosting sites in males than in females. The individuals rigidly guard their roosting sites by displaying agonistic behaviour toward intruders. Such a site-specific pattern of roosting seems to serve the function of accommodating many individuals within a small space available in an organised manner.