A PARAPATRIC CONTACT AREA BETWEEN 2 SPECIES OF MOLES - CHARACTER DISPLACEMENT INVESTIGATED THROUGH THE GEOMETRIC MORPHOMETRICS OF SKULL

Character displacement is investigated in sympatric populations of two related species of European moles, Talpa europaea and T. romana, alon g the zone of parapatric contact in Central Italy. Morphological varia tion of the two species is analysed through the geometric morphometric s of skulls by comparing sympatric to allopatric populations. The morp hometric approach enabled us to consider separately the effect of size and shape on character displacement, while the analysis of relative w arps allowed us to recognise and visualise specific regions of the sku ll involved in the phenomenon. Results suggest that size and shape can play a role in the local differentiation of the two species. Differen ces in size are sharper in the sympatric populations, while shape diff erences possibly related to character displacement are expressed by fe w relative warps in both the dorsal and the ventral view of the skull. Morphological features involved are concentrated in the zygomatic reg ion,thus suggesting that character displacement is mainly related to t he efficiency of food assumption and processing.