Polimorfizm okraski ou stepnogo sourka na Ukraine [Polymorphisme de la coloration chez la marmotte des steppes. Polymorphism of marmots coloration in Ukraine].

Résumé

Property of the steppe marmot populations is the relative colour homogeneity of the skin coloration (Kalenichenko 1960, Averin 1928, Severzev 1936, Semichatova, Titkova, 1976). Then the cases of aberrant coloration of the steppe marmot in the Ukraine are more interesting (Tokarskiy, Bibikov, this collection, p. 37). It was known ealier some examples of albinism and melanism with some other representatives of Marmota genus (Hamilton 1934, Armitage 1961, Kapitonov 1978, Isakov 1987). A.A. Migulin (1938) distinguished bright and dark variant of marmots in the territory of Starobelsk, region of Donetsk. The analysis of literature shows that animals of abnormal coloration are quite rare in the wild nature. Their percentage or the general number of population can be compared with the frequency of rare gene spontaneous mutations. The present investigation has resulted difference from the theoretically determined frequency division of abnormally coloured marmots in region of kharkov and at the same time, lack of such an information in region of Lugansk and some districts of Kharkov region. According to the pattern proposed by S.M. Gershenson (1946), the stages of mutation features fell off from the normal, and can be classified from taxonomic viewpoint as intermediate one between adapting dimorphism and ecotype. It can be following characteristic of the space distribution : melanist are found polytopically, but are not spread over the considerable part of areal. The territory where melanists are available can be conditionally divided into two categories : 1- number of black marmots is more than 1% general quantity of the colony, 2- number of black marmots up to 1% We refered to the first category 3 anomalies : Khatnyaya, Kolodeznaya and Velikoburlukskaya. The districts of the second category form mosaic diagram. The analisis of melanist encounter frequency resulted the availability of unequal in content of aberrant colonies on one hand, and general trend to the increase of melanism quantity and, on the other hand, the appearence of the other colour morphs. During the investigation in the territory mentioned above we also encountered animals with the intermediate between red and black coloration, acromelanists and brishtly coloured marmots (down to partial albino). Investigations carried out together with K.B. Armitage showed the existence of four marmotts with skin colour which can be considered as blue. Concerning the reasons of higher frequency of melanists and the appearence of other abberants in the territories mentioned above we suppose their complex ecoanthropical nature and we also consider that the melanistic syndrome of marmots is the integral non-specific adapting reaction determined with the factors of ecological risk, including anthropogenic to the first place.