Морфологическая дифференциация серого сурка (Marmota baibacina) и тарбагана (M. sibirica) в Южной Монголии. Morphological Differentiation of the Altai Marmot (Marmota baibacina) and Mongolian Bobak (M. sibirica) in Southern Mongolia [Différentiation morphologique de la marmotte de l'Altaï et de la Bobak de Mongolie en Mongolie du Sud].

Résumé

Based on a number of measurements and qualitative parameters, diversity in the skull structure was analyzed in the Altai marmot and Mongolian bobak from Mongolia, including the overlapping zone of their ranges. Using various methods of cluster and discriminant analysis, classifications were performed for (1) individuals of the total sample of each form and (2) geographic samples. In the first case, the diversity patterns of the Altai marmot and Mongolian bobak were considered and in the second case, the similarity between individual geographic samples was analyzed. The forms baibacina and sibirica showed statistically significant differences both in measurements and in qualitative parameters, this corroborated that these two forms were valid species. The quantitative and qualitative parameters distinguishing M. baibacina from M. sibirica are described. As regards to the inner differentiation of these forms, only the centralis form can be distinguished with certainty among Altai marmots. Among Mongolian bobaks, the animals from Transbaikalia are distinguished. Other clusters of Mongolian bobak samples are not distinctly differentiated, and their separation requires further confirmation based on a wider range of geographical and morphological data. The study provided no evidence for introgressive hybridization between the forms in the contact zone, i.e., animals with intermediate phenotypes were not observed.