Sexual differences in the morphometric traits of the black forest-steppe viper, Pelias berus nikolskii (Vedmederja, Grubant et Rudaeva, 1986) (Viperidae, Reptilia), from the Voronezh region

We studied sexual dimorphism in the black forest-steppe viper, Pelias berus nikolskii (Vedmederja, Grubant et Rudaeva, 1986), inhabiting the Voronezh region. From 2008 to 2017, 118 snakes were captured, of which 84 were males and 34 were females. Body length, tail length, and five head measurements were taken from the individuals was calculated. Analysis of Covariance showed that males and females differed in all traits except the greatest width of the head and head length. Traits can also be subdivided into those with respect to each other that retain sexual dimorphism throughout the growth of the snakes, and those whose sexual dimorphism with respect to each other varies with body size. Discriminant Analysis showed that tail length makes the main contribution to the gender distinction: with the same body length, tail length will almost always be greater in males than in females. The width of the head at the eye level is of less importance: with the same tail length, the width of the head at the eye level will often be greater in females.