Holarctic Marmots as a factor of Biodiversity.
Rumiantsev V.Yu;, Nikol'skii A.A. & Brandler O.V. eds.,
3d Conference on Marmots (Cheboksary, Russia, 25-30 August 1997),
Moscow ABF 1997, 216p. : 197.
THE ROLE OF STEPPE MARMOT IN MAINTENANCE SPATIAL-ETHOLOGICAL STRUCTURE OF MIXED SETTLEMENT
THREE SPECIES GROUND SQUIRREL
Penza State Pedagogical University,
On investigation of a sympatry zone of russed (Spermophilus major) and spotted (S. suslicus) souslics on a right bank of Volga in Ulyanovsk region in 1995 it was revealed a mixed settlement of souslics and steppe marmot. The contact settlements bobac with S. major, S. suslicus, S. fulvus are well known, but inhabitancy of 3-rd species ground squirrel in one colony is marked for the first time. The basic reason of the occurrence a settlement is the moving russed souslic in region (Ermakov, 1996).
During the 2-nd field seasons (1996-97) behind the specified settlement were carried out ethological research (600 hours), thus there were estimated a territoriaty, a submission of burrow activity and alarm signal system, and also level of aggression individuals.
Territoriality. The colony is characterized a rigid introspecies territoriaty and an independent distribution of territory between individuals of various species. The home rangers individuals of one species are blocked unsignificantly (up to 10 %). In comparison with it the home rangers of different species are absorbed almost complete or blocked for extensive zones (up to 80 % is marked, on a range of 1 marmot family there are 6 home rangers of russed souslics and 3 - of spootted). The unique condition, which is observed at spatial organization of colony, is sufficient removal of the centres of home rangers individuals. The exclusive right to a choice and personalisation of territory has marmot. Two other species are develop theirs home rangers depending on territorial preferences the first. The guards of rangers is carried out basically from individual encroachments of a species.
Burrow activity. Steppe marmot occupies the dominant role. Souslics willingly use systems fodder burrows of marmot family. Passively it is displayed in a leaving souslics at danger in burrow sites, thus is more often by them use russed souslics (9 to 1). In some cases it is observed the integration of hole systems of species, when, beginning an independent course (courses), holes of souslics leave in burrow sites. It is interesting also, what even the pairing of russed souslics, occurring in pure settlements on a surface (Bazhanov, 1946), in specified colony goes in burrow sites.
The alarm signal system. The leading specie is marmot. Creating the steady alarm communication in all territory of colony, it removes a part of loading on guards of settlements from both species of souslics . From them the most contactly the russed souslic. He supports the communications not only much more active, but also reacts on it more adequate. If spootted souslic at marmota vocalization directs to hole (in all cases on 1 alarm signal), S. major (on 4-8 shouts) pricks up for pillar or on 4-th paws. Thus his further behaviour is in direct dependence on removal of a source of danger and degree of threat (leaving in a hole, vocalization, returning in an initial condition). The alarm signal system of souslics in the given settlement is also unequal for value: marmot answers for pricking up only on calling of russed souslic, and vocalization of spootted souslic is poorly expressed.
Aggression. At a high level introspecies aggression of souslics the interspecies aggression in a settlement is rare, and occurs only in case of non-observance a critical individual distance (5-10 m). In this sense the observable cases at approaching danger to mixed leaving marmots and souslics in one burrow site are indicative repeatedly.
It is necessary to search the reasons of beginning for observable mutual relation in morpho-ecological advantages and greater sociality of the given specie.