Kannibalizm sredi stepixh sourkov [Cannibalisme chez les marmottes des steppes. Cannibalism among steppe marmots].

Résumé

In the nature, when the predators do not affect substantially the marmot populations (Shubin, 1964, Seredneva, 1985), it is reasonable to permit the existance of some mechanisms of autoreduction of these rodent quality. According to the purpose of the majority of reseachers, these mechanisms are of the social nature and keeping adapting quantity of the population is prodide for due to grouping formed within the populations, and it have complicated hierarchical and territorial relationships (Armitage 1987, Arnold 1990 a, b,), which take shape against a background of energetic limitations. Juvenile marmots are the most vulnerable energetically. Earlier K.B. Armitage (1976), V.I. Kapitonov (1978) and some other pointed out principal infant deathes. Under group hibernation their vulnerability is partially balanced due to older sibs (Arnold 1988, 1990b, Vasilyev 1990). During the investigations there was no case of hibernation death of marmots, despite of their autum weight was lower in experimental conditions than the weight of the same age marmots in the natural conditions. And the range of negative temperature loads was wider and hibernation mostly was one at a time. To the opposite, during the marmot hibernation we registered 3 cases of complete and 1 case of partial cannibalism, besides in case of partial and 1 case of complete cannibalism marmots were in isolated cells. In the nature we observed the only case which might have led to cannibalism. Exhausted adult female with the skin damaged by subcutaneous parasites after being placed into the same cell with other juvenile individuals was proned to predatory actions. K.B. Armitage (1979) described earlier the cases of cannibalism among yellow-bellied marmots. In connection with the mentioned above the cases of cannibalism can be examined as some explanation of hibernation (and quasi-hibernation in fact) death of under juveniles. Probably, the phenomenon of cannibalism in the nature is spread more widely than it was ascertained by the researchers. I consider that cannibalism among steppe marmots is social mechanism of emergency correction of population quantity in response to sharp irregular decrease in food resource.