SOUTH-STEPPE SETTLEMENT OF BOBAK MARMOT (MARMOTA BOBAK MULLER, 1776) AND THE FEATURES OF ITS RELATIONS WITH THE ENVIRONMENT UNDER THE CONDITIONS OF THE NIKOLAEV DISTRICT

Abstract

The marmot is a typical stenotope of the Ponto-Caspian Sea, the primary area of
which is clearly tied to the landscape-biocenotic complexes on the Steppe / ForestSteppe border stretching from the Dnieper to Tobol. The species (together with several
species of gophers, rodents and ungulates) forms persistent faunistic communities
supporting the ecological balance of local biocenosis. Bobak, like other marmots, is
optimally adapted to existence in the north-steppe open landscape. It is suited for life
in sharp seasonal-climatic amplitude by a burrowing lifestyle, ability to truly
hibernate, development of specific physiological and biochemical mechanisms and
complex social and colonial organization of the population. Because of the agrogenic
transformation of the Eastern European steppes in the beginning of the twentieth
century the bobak retained only eastern, partially isolated fragments of the primary
range, which led to the need for its artificial settlement.
The analysis of conditions of the release place and the assessment of the
protection level indicates to sufficiently good stationary and fodder characteristics of
the area and the absence of poaching. At the same time, uneven orography of the
settlement territory and the presence of dense vegetation in the beam thalweg give air
and ground predators an opportunity to attack the bobaks successfully. The latter do
not have time to escape from the suddenly emerging predators even at a distance of 7–
10 m from the burrow. Unstable seasonal hydrological regimes of groundwater are
also unfavorable for successful wintering of the marmot. In some years the
groundwater fluctuations in the soils of the beams served as a cause of flooding and
death of marmots. The response of the population to these factors was the
displacement of the settlement as a whole higher along the slope of the beam and the
location of the holes not in the clay layers, but in the loess layer.
The results of long-term studies of two isolated settlements of Marmota bobak in
dry-steppe terrain and analysis of natural and climatic conditions in the places of
introduction and set of practical measures of protection allow concluding that the
species introduction and successful acclimatization in the dry-steppe area of the
northwestern Black Sea coast is undoubtedly possible. It is found that the negative
results of bobak releases in the Steppe, especially in the southern Steppe, are
associated not with the one-time disappearance of the colony, but with the gradual
suppression of isolated micropopulations. The main reasons for their suppression are
the discrepancy between the places of release and the ecological needs of the
introduced species, the insufficient level of collective security of a quantitatively small
colony and the lack of effective protection of the settlement from foxes and wolves.
Keywords: bobak marmot, introduction of marmot, hunting animals of the
Nikolaev region, fauna of the dry Steppe of the North-Western Black Sea region,
biodiversity of mosaic agro-landscape.