Influence of environmental factors on number dynamics and spatial structure of the tur (Capra caucasica) population in the Caucasian Reserve
2014
Trepet, S. A. | Eskina, T. G. | Bibina, K. V.
The number and structure of the tur (Capra caucasica Guldenstaedt et Pallas 1783) population on the territory of Caucasian Reserve (Western Caucasus), as well as peculiarities of the effect of natural and anthropogenic factors on the population, were studied based on ideas of meta-population species dynamics. Fourteen local tur groupings were united into three groups by the similarity of long-term number dynamics. A negative effect of winter, which deviated from the average long-term winter by the level of snowiness, on the tur population was detected. Snowy winters damage not only males (that frequently die in avalanches), but also affect the birth rate subsequently; the portion of females, in spite of the male death, decreases anyway two years after winter, as well as the portion of underyearlings. It was demonstrated that the snowy winter effect is manifested only when the animal density is rather high. The following tendency was detected for the tur population: the greater the density before the winter, the larger the decrease in the animal density after it (and this tendency weakens one year after the winter). Wolf predation has no negative effect on the tur population in the reserve. A maximal association between the tur density and wolf density was found at a tur density up to 50 individuals/1000 hectares. With a further increase in the victim density, the wolf density changes independently of the tur density. Turs in the reserve are not easily accessible to poachers due to habitat peculiarities, and therefore, the role of poaching in the dynamics of their numbers is not significant.
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