Unusual colour form of Siberian pit viper (Gloydius h. halys) from the northern edge of its area

Abstract

In this report, I describe the unusual colour form of Siberian pit viper (Gloydius h. halys) from the marginal population in Novosibirsk region (West Siberia, Russia). This morph was named “bronze” and occurs of 16% of individuals. To the best of my knowledge, such colour pattern does not known from other parts of G. halys area.