The age distribution in the Taimyr population wild northern deer (Rangifer Tarandus) in the first decades of 21 centuries

Abstract

Objective: mathematical demography means to identify and evaluate the age distribution of male and female of Taimyr tundra reindeer in the first decade of the XXI century and future trends in demographic situation Taimyr population.Materials and methods. The base material for evaluating the current state of the population age structure Taimyr steel fishing representative sample of male and female wild deer (n = 10845 individuals) collected in the West, Central and Taimyr Putorana in 2001-2008., And the deer samples (n = 1569 individuals), the floor of which is unknown. Determination of individual animals from age and older (n = 9773 individuals) performed on histological sections of cutters according to the corresponding procedure. To repay the random deviations of sample data because of a lack of presence of immature animals (calves, yearlings, young 1-2 years) (selectivity of fishing is directed primarily at the production of individuals older than 3 years, why animals in different age groups in the samples is greater than there are in the population) applies a smoothing procedure. Then, positive deviation of the number of individuals in the same age group were leveled due to negative deviations in adjacent groups.Results. By smoothed age ranges of the field samples from 2001-2008 the current age distribution of Taimyr wild reindeer calculated and analyzed. The study showed that the theoretical current age distribution of males with realized breeding is 77.03, females - 80.56, in the combined groups of animals - 82.35%. The real population has 18-19 age generations of males and females. The reproductive core of males from 3 to 10 years old is 48.43%, individuals of age limit 11 years and older occupy 1.96% of this sex and age structure, calves and young animals for 1-2 years - 24.64%. For the reproductive part of females aged 3–15 years, the overall age distribution is 55.34%, and the proportion of juveniles and young animals, according to calculations, is determined in this part of the population at 25.16%. In the combined current age distribution, males, females: calves and young animals accounted for 27.72%, the sexually mature part with animals of older and age-specific ages - 54.63%.Conclusion. Demographic Taimir population modeling operation in the first decade of the XXI century long materials commercial samples collected at commercial points shown at current age distribution of the realized and reproduction conditions for existing commercial load males - 77.03 for females - 80.56 and for unified groups (males, females) - 82.4%. Meanwhile, the steady state and stable age distribution Taimyr tundra wild deer can reach a middle-level only when the fecundity of female reproductive generations with clean reproduction rate (R0) equal in population groupings 1.0