Morphometric differences between Australian wild rabbit populations

Abstract

Morphometric distances, based on 20 skull measurements, were determined between eight localized Australian wild rabbit populations and a sample from the British Isles. To minimize the influence of age-associated variation in the Australian series, only animals estimated to be at least 12 months old (based on epiphyseal and dry eye-lens aging techniques) were included. Sexes were pooled after univariate and multivariate testing for sexual dimorphism and eliminating bizygomatic breadth. By means of univariate statistics, Mahalanobis generalized distance and canonical analysis, the various Australian and British Isles samples were shown to differ appreciably, morphometric distance increasing clinally in eastern Australia with geographic distance from the point of introduction (Geelong, Vic.). Based on a plot of first and second canonical variates, differences between three Canberra area samples were comparable in magnitude to those between certain populations separated by much greater geographic distances. These findings are consistent with results of studies of blood protein variations in Australian wild rabbit populations.