Variation in cranial form and sexual dimorphism among five European populations
of the otter Lutra lutra
Lynch JM , Conroy JWH, Kitchener AC, Jefferies DJ, Hayden TJ
JOURNAL OF ZOOLOGY 238: 81-96 Part 1 JAN 1996
Abstract:
Craniometric variation between otters Lutra lutra (L.) from Ireland, Scotland,
Shetland, Norway, and Czechoslovakia was examined using multivariate statistical
analyses. Significant sexual dimorphism in cranial size and shape occurred in
all samples, although the degree of dimorphism varied between samples, with the
Irish sample exhibiting the most. Morphological differences were also observed
across samples. Three groups were observed; Irish, Scottish, (Mainland and Shetland),
and Mainland European, though within the two composite groups the samples were
still differentiable. There was a good agreement between the patterns of variation
between male and female samples, but morphological differentiation was not significantly
correlated with geographic separation. These results are discussed in the light
of our current knowledge of the ecology of the species in Europe. It is argued
that, while there is morphological evidence for subspecific status of the Irish
otter (as L. l. roensis), further investigations of morphological and genetic
variation across Eurasia are clearly required.