The reproductive age of males of the taimyr of wild reindeer (<i>Rangifer tarandus</i>)
Authors: Shapkin A. , Arsentseva N. , Sukhanova N. 
Published: January 2023

Purpose: to study the age of manufacturers, the share of their participation in the rut and assess the contribution of males of wild deer to the implementation of reproductive cycles of the Taimyr population in the period 1993–2008.

Materials and methods. The fees of the material were carried out in the period 1993-2008. On Western Taimyr and Putoran plateau. To identify the environmental-morphophysiological characteristics of males (a pre-productive group 1–3+, reproductive low-ranking and high-ranking males from 4 years and older) performed selective weighing of 38 males in the summer-autumn period (August-October). The body weight of the animal is an indirect reproductive sign of its strength. For low -ranking, animals were taken with a live weight of 80 to 130 kg. High -ranking bulls with body weight for 130 kg were attributed. During the period of spring migration 2001, 2004, 2006. 37 males are balanced. The reproductive success of males was evaluated from the values of the potential fertility of adult females in herds of spring migration flows 1998–2006. During scientific shootings in April -May, 218 pregnant and Yalov female wild deer deer were examined. The reproductive contribution of adult males in the seasonal reproductive cycles of this part of the Taimyr population (the number of fruits per 100 adult females) was calculated from the equality of two relations (proportions) - sexually mature females of this commercial sample (A) to pregnant females of this sample (B) and 100 sexually mature females ( c) to pregnant females (D), i.e. By the main property of the proportion. The individual age of the males was evaluated according to the layered structures of the incisors [12] of the formed layers of the cement of the cutter I1, previously decalcinated by a 5 % solution of nitric acid. Sections of males from samples 1993–2008. Received on a microtome with a freezing model X MZ-1. To count the annual rings of wild reindeer, samples were painted with hematoxylane Erlich.

Results. According to selective data (n = 128), the reproductive age of males of Taimyr wild deer was investigated: bulls of 14 age groups from 3 years and older are involved in Gona. The main contribution is made by age groups from 4 to 9 years. These males make up 78.9 % of the reproductive nucleus that supports the reproduction of the population. Until the age of 7, the number of males participating in the rut is growing. From 8 years, the fraction of manufacturers is reduced. In terms of age distribution, the decline of highly productive males begins with 6 years. The largest number of potential manufacturers is provided by 5–7-lite groups (48.42 %), but the maximum number of reproductive males in age distribution is concentrated in a 5-year group, quite numerous in the population-9.4 %. The maximum reproductive age is 16 years (1 male or 0.78 % of the reproductive nucleus). The average age of reproductive males in the population of 7.14 years. The race of animals in West Taimyr flows from October 19–20 to November 9–15 (3-4 weeks). Mating occurs both in short -term large aggregations that combine several hundred to one thousand animals, and in harem groups from 8 to 30 individuals. The average size of harems was detected in the range of 16.2 goals (n = 24). The average indicator of the reproductive contribution of males: 76.6 ± 3.28 fruits per 100 sexually mature females.