LAUSR

The abundance of the saiga antelope (Saiga tatarica tatarica L., 1766) in the Northwest Pre-Caspian region has remained at an extremely low level over the past 20 years. Comparison of some biological parameters of the population for periods with different numbers of animals made it possible to reveal a number of low-population features. Thus, along with a decrease in the number of saigas (from 800 000 heads in 1958 to 4500 in 2016), its habitat area also decreased (from 60 000–70 000 to 2000–3000 km2, respectively), and a significant part of the population transitioned to a sedentary lifestyle in the protected areas of the Chernye Zemli ecoregion. A long-time deficiency of sexually mature males in the population (less than 10%) led to a decrease in its growth and, consequently, to a decrease in its number. At the same time, the total fecundity of females decreased (from 1.27 ± 0.25 calves in years of high abundance to 0.92 ± 0.39 recently) due to an increase in barrenness in different age groups caused by the lack of males in the population. Males prevail over females in newborns (51.9 and 48.1%, respectively). The increased weight of newborn saiga calves (100 g on average for both males and females) and their decreased mortality in the first days after birth (under favorable weather conditions) indirectly indicate the normal course of embryogenesis and a sufficient quantity and quality of feed. An increase in the proportion of sexually mature stags will lead to an increase in the population number, as the reproductive functions of the population practically did not change during the period of its depression.