Variation of craniometrical characters in an artificial population of Cervus nippon from Askania-Nova, Ukraine

Abstract

Craniometrical characters of adult sika deer from an artificial population, which was created by import of animals from a natural population from the Primorsky Krai of Russia, are analysed. It was revealed that the mean value of variation (by 11 characters) of skulls of sika deer is 3.56 ± 0.35 in males and 3.89 ± 0.33 in females. Males are significantly larger than females (p < 0.001) by all characters. The study of craniometrical characters of the sika deer using principal component analysis showed that 93.3 % of total variance is described by the first principal component (PC1). The highest, though quite equal, factor loadings on PC1 have characters of length (full length, condylobasal length, basic length). Study results suggest that sex-related differences in C. nippon by craniometrical characters are expressed by general linear dimensions and by proportions of the skull. The correlation matrix of craniometrical characters of adult sika deer from the Askanian subpopulation shows a relatively weak dependence between different parameters. It was established that the coefficient of correlation in most pairs of characters varies from 0.02 to 0.96 in males and from 0.01 to 0.97 in females. The highest coefficients of correlation in both males and females (r = 0.96 and r = 0.97, respectively) are revealed between the condylobasal and basal lengths of the skull. Correlations between cranial indices are significantly lower compared to craniometrical characters. The highest coefficient of correlation in both males and females has the variation of the index of mastoid width in relation to the relative largest skull width (r = 0.72). Skulls of sika deer from the Askanian subpopulation (of both males and females) have significantly larger dimensions compared to those in animals from the natural population from the Primorsky Krai.