The life of animals is natural communities within the strict framework of the sex ratio and age groups. Changes in environmental conditions or shooting, aiming at the removal of any one group, will inevitably lead to a change in the number of animals (population). The ratios of individual groups of animals and limiting the population density of roe deer in summer habitats support some intrapopulation factors.
Such factors include the relationships that arise within a single family, as well as in the aggregate of all individuals living in the area. In fact, how do you explain that some plot fairly evenly populated deer? Why is the same animal or group animals live around the same place for a few years? Questions ethology, or behavior of animals began to be developed relatively recently, and their solution enabled us to explain many aspects of the life of animals and birds.
Roe deer that live on a relatively small area, known both forage plots, watering, place a good defense, but they are also well aware of all of his closest kinsmen. For this there is thousands of years to work out and fixed hereditary territorial signaling system, including the identification marks and sounds. Territorialism in deer show activity only in certain seasons of the year and the property of an adult animal.
In areas with high numbers of deer all land divided between individual males, which from May to September, and in the European part – from April to August, every morning and evening to manage their land borders and put urine and other marks, or, as they say, mark them. Lot Size roebuck is from 7 to 100 ha (in different parts of the species' range). For the labels they use and allocation of the frontal mezhkopytnyh glands. These secretions from each animal is individually smell. They are applied to the thin trunks of trees and the forest floor.
On the site of adult male can live only females and young of the year of birth. Younger males master casts from its territory. I also take the female mark their sites and do not let them in the other adult females, although there is some overlap areas. Period territorialism females lasts until the end of July.
Tagging of deer colored collars are well seen from a distance nomerovannymi labels found that inhabit both land animals, which have their own territory, and those that do not have a plot. The latter, as a rule, are growing up, and 1.5 – 2-year-old animals. This is like an excessive portion of the population expelled from their places of birth and forced to look unoccupied, usually the worst areas.
Sustainable game management must be based on hunting animals, not having its own territory. In that case, will be supported by a stable deer population density is the most beneficial to the population ratio of males and females, young and adult animals. Will also decrease damage to the forest plantations, caused excessive number of roe deer in the land.
In the area, which control the number of deer is mainly the big predators, there is an equal ratio of males and females in the population, ie, 1:1. In the fall, before hunting season, growing up young, at the age of 5 – 6 months, is approximately 1/3 of livestock. The remaining 2 / s divided evenly between adult males and females, which include and 1.5-year-old individual.
This ratio sex and age groups were found in the undeveloped world hunting grounds Okunevskaya Vitim plateau area in the mid 60's. After conducting experiments in the extermination of wolves in the deer population in this area has increased dramatically (from 34 to 42%), the number of young animals by reducing their deaths for the period between birth and the attainment of six-month-old.
It should be noted great difficulty correctly estimating the ratio of sex and age groups in the population. Less cautious that young who has a territorial plot. For this reason, for example, when viewing large quantities of roe deer, hunted by hunters in Sayan, found a large number of calves (134 of 231).
Very interesting information age composition can be obtained by analyzing mikrosrezov or grinding of the teeth. In particular, we identified the following age structure of the population on the Vitim plateau (Transbaikalia) in the fall of 1964 and in the Sayan Mountains, 1970 – 1972. (Table 2).
As the ratio of the number of animals of different ages can calculate the estimated annual mortality rate of each age class. For example, in the period of life between 1.5 and 2.5 years of waste were: 59 – 37 = 22 individuals.
Approach of the individual groups in the population of some animals can even approximately determine their annual decline, and hence calculate the rational norms shooting.