Meeting Abstract
The forelimb morphology and digging behavior of moles (Talpidae) are unique among fossorial mammals. Moles dig only with their forelimbs which are oriented laterally. Among mole species, musculoskeletal specializations of the forelimbs vary depending upon whether a species is aquatic/fossorial, semi-fossorial, or completely fossorial. To date, we do not know whether this morphological diversity is matched by disparity in performance. In this study, we compared burrowing performance between fossorial moles (Eastern moles, Scalopus aquaticus) and semi-fossorial moles (Hairy-tailed moles, Parascalops breweri) in soils of different compactness. We measured linear burrowing velocity, soil displacement, tunnel length, and the size of the area explored when the animals built their tunnels. We also investigated how these performance measures changed in response to loose, intermediate, and compact soils. Linear burrowing velocity did not differ between Eastern and Hairy-tailed moles, regardless of soil compactness. However, the highly fossorial Eastern moles moved more soil, built longer tunnels, and explored more area during tunnel construction. It appears that the ability to displace soil and construct tunnels, not the speed of movement in the soil, varies among mole species that differ in their dedication to fossoriality. With data from additional species, the results of this study may shed light on the evolution of morphological variation associated with fossoriality and fossorial ecology.
