Morphological peculiarities as indicators of natural history of sable (Martes zibellina) in North-Asia Pacific coast

Abstract

Few studies exist on phenotypic composition of the sable populations in the Russian Far East, China and Japan. We present new data on the morphological diversification of sable for 20 mainland and island populations in an effort to document existing variability and produce baseline data that would be useful in constructing phylogenies for this species. Сlinal variability of skull size, cranial phene, foramen in fossa condyloidei inferior (FFCI), and fur coloration is revealed. One district, Central Sikhote-Alin, is characterized by sables with the minimum cranial size and the maximum phene expression. The area between the Uda River and Goryun and Amgun rivers is inhabited by sables of the darkest fur coloration. Moving out from those areas in all directions we were detected a trend of increasing skull size, reduction of cranial phene, and decreasing color intensity of fur. The skull size of sable is consistent with Bergmann’s rule. Special attention paid to the particular morphological properties of insular populations in specific climatic conditions and under isolation from the continent. They are characterized by minimal expression phene FFCI (Bolshoi Shantar, Iturup, and Hokkaido islands) and larger skull size, especially in sable of Kamchatka Peninsula. It is hypothesized that the area of the lower Amur Basin was a source of sable postglacial dispersal on the Eurasian Continent.