Cranial variation of the greater horseshoe bat Rhinolophus ferrumequinum (Chiroptera: Rhinolophidae) from the central Balkans

Abstract

Cranial size and shape variation of the greater horseshoe bat Rhinolophus ferrumequinum from territories in Serbia and Montenegro was examined using geometric morphometric methods. Statistically significant size and shape differences among specimens from distinct geographic regions (the Carpatho–Balkanides, the Internal and External Dinarides) were observed. Bats from the Carpatho–Balkanides have the smallest crania, while those from the External Dinarides have the largest ones. Compared to specimens from the Carpatho–Balkanides, bats from the other two regions have crania wider in the temporal and elongated in the facial region, while the basicranial region is smaller. Our analysis of sexual size dimorphism revealed no statistically significant differences between males and females. Even though significant sexual shape dimorphism was observed, cranial shape differences among bats from different geographic regions exceeded those between sexes. We also found that size and shape vary with climatic factors. Allometry has statistically significant effect on cranial shape variation and somehow contributes to covariation between cranial shape and environmental variables. Although the examined bats were from a relatively small territory, we have provided new insights into important issues like geographic variation, sexual dimorphism and allometry in this species.