Sexual dimorphism in the skull of the European mink Mustela lutreola from NW part of Russia

Morphometric variation in 22 characters of 86 skulls of the European mink Mustela lutreola (Linnaeus, 1761), from the NW part of Russia, has been analysed. Stepwise discriminant analysis was used to estimate craniometric variables for sex determinations. Two characters (zygomatic breadth and interorbital width) are enough for the 96.5% correct classification. The male skull of M. lutreola is characterised by a relatively high neurocranium, widely arranged zygomatic arches, a wide rostrum, and by wider auditory bullae and higher mandibles. Sexual size dimorphism of M. lutreola is less than that of other similar-sized mustelids - Mustela putorius, M. eversmanii, M. sibirica, Neovison vison. The results are discussed in relation to the existing theories on sexual dimorphism in mustelids.