Age and sex skull variation in a model population of the common shrew (Sorex araneus)

Sexual and age variation of the common shrew was assessed in 173 individuals captured in the Novohradske hory mountain range in South Bohemia, Czech Republic. Age variation was found in seven of the fourteen measurements examined. In six of them (height of mandible, height of mandible measured below the first molar, length of mandible, cranial width, condylobasal length, length of neurocranium), values in adults were higher than those in juveniles, while the opposite was found for the length of the lower incisor. Evidence of sex differences was found only in three measurements: height of mandible measured below the first molar, cranial width and length of the lower incisor. Our results suggest the need for separating age and sex groups in studies of skull variation in Sorex shrews.