E-catalog        

The age of 76 individuals of Pelias berus (Viperidae, Serpentes) from different altitudinal belts of the Kuznetsky Alatau Mountains (290–1600 m a.s.l.) was determined by the method of skeletochronology. It was shown that the body sizes of individuals of different age groups overlap, and the oldest individuals are not the largest. The maximum lifespan of females is 11 years (middle mountains of the eastern macroslope), of males — 9 years (low mountains of the western macroslope). The reproductive core of populations is formed by males and females of 4–8 years old. The age of breeding females is from 5 to 11 years, the fecundity of females ranges from 7 to 15 youngs. Females reproduce once every 2–3 years, gaining body weight sufficient for bearing the offspring. Significant differences in the male to female ratio in the samples from the low-mountain population and the combined sample of P. berus from the western macroslope were not revealed. During the active period the significant differences in male to female ratio are associated with the increased spring activity of males and the frequent meetings of pregnant females in summer.