Biting Performance in Teeth-Digging African Mole-Rats (Fukomys, Bathyergidae, Rodentia)

Phenotypic variation is channeled by adaptation to local environments and phylogenetic constraints. The morphology of the obligatorily subterranean African mole-rats of the genus Fukomys has been shaped within the context of their underground habitat, posing particular limits on the animals' morphology. Especially the biting apparatus has likely evolved within severe evolutionary constraints, as it is used for feeding on hard geophytes, for digging complex tunnel systems, and for defensive purposes and social interactions in a colony. We studied interspecific differences in bite performance among three taxa, in relation to their skull anatomy and skull shape. Data on biting performance were gathered by in vivo measurements and compared with model simulations. It is shown that the model simulation is a good proxy for in vivo measurement. Scaling of bite force is positively allometric relative to head size. Moreover, differences in biting performance exist between taxa, which may be linked to differences in their ecology. This study will eventually enable us to analyze the evolutionary pattern behind the variation in structure and performance of the biting apparatus in Fukomys mole-rats.