Dynamics and structure of a field roe deer population

Abstract

1Jan KAŁUZIlŚrSKI Kałuziński J., 1982: Dynamics and structure of a field roe deer population. Acta theriol., 27, 27: 385-408 [With 9 Tables & 10 Figs.l The purpose of these studies was to obtain data on variations in numbers, reproduction, mortality, survival and age and sex structure. The data were collected over a period of 14 years, and using them as a basis a quantitative balance was drawn up for a population living in an agrocenosis. Average density of roe deer was 7 individuals/100 ha, and the number born was 1.9 young per female. Natural mortality among young roe deer was high (56% of the number born) and distinctly influences effective production, the average value for which is 0.8 juv/female. Mortality among adult animals was on an average 21%, varying from 7-51% of the spring numbers from the precedingyear. In years which prove catastrophic for the population about 50°/o of the roe deer die during the first year of life. Average length of life of an individual was 3.5 years. Females predominated over males throughout the whole study period (56:44). Game shooting refered first of all to animals from 0-7 years old from the population, and applies to 89% of males and 84% of females. Population numbers were determined by mortality among young and adult animals and by constant game shooting of about 8.1%, and apart from catastrophic years exhibits a tendency to increase. Losses due to game shooting and average natural losses were effectively replenished in the study population.

Roe deer mortality due to mechanization of work in agrocenoses

“…The numbers of roe deer on an average for the last 13* years has been 7 individuals per 100 ha during the spring period (Kałuziński, 1982).…”

Population characteristics of roe deer inhabiting a small forest

“…1). This increase was, however, abruptly inhibited in 1979 after the exceptionally severe winter of 1978/1979, during which the head of roe deer in the whole of the western part of Poland, including those in the field area surrounding the study area, was reduced by about 50% (Kałuziński, 1982). As early as the first year after the winter catastrophe there was another increase of 100% in the numbers in the Słonin Wood, in which the density of these animals was 51.6 individulas per 100 ha in the summer of 1975, and on an average for the period 1977-1980 32.2 individuals per 100 ha.…”

“…This is due to the large proportion of young individuals up to 3 years old in the population. This would appear to ishow that despite the very great density (30-50 individuals/100 ha) mechanisms evoking increased emigration of excess individuals into the nearby fields, in which density at this time was only 7 individuals per 100 ha (Kałuziński, 1982), were not yet acting to any important degree. Anticipated further length of life arising from the calculated "life table" is disproportionately low for roe deer in the young age classes, being only about 3 years (Table 2).…”

“…These forests, varying in area from 200-300 ha, are distinguished by unusually great density of settlement by roe deer, up to 100 individuals per 100 ha during the spring period (unpublished data from the Polish Hunting Association Research Station). Groups of these animals in small forests have not been specially distinguished in general descriptions of field roe deer populations (Kałuziński, 1982). There are, however, grounds lor suspecting that at least in larger stretches of such wooded land roe deer may live which cannot be fully identified with field roe deer.…”

Grouping tendencies in roe deer under agrocenosis conditions

“…Agriculture in this area is distinguished by the very great intensity of agrotechnical operations. Further details of the experimental area are to be found in the study by Kałuziński (1982).…”