Cranial Variation in the Siberian Weasel (Carnivora, Mustelidae) and its Possible Taxonomic Implications.

Morphometric variation in 23 cranial characters of 555 Siberian weasels () was studied across its whole distribution range. Most of the distribution range in Siberia and China is occupied by medium-sized weasels, whereas the eastern part of the species range - including the Russian Far East, Korea and eastern China - is occupied by the larger form. Specimens from the Pacific islands (Jeju and Tsushima) were morphologically closely related to the western form of than to the neighboring continental weasels. The western form can be treated as nominotypical subspecies Pallas, 1773, whereas the eastern form can be treated as Brass, 1911. Small-sized weasels from the eastern Himalayan area (Myanmar and southwestern China) form a distinct group within , and they were treated as a subspecies; (Milne- Edwards, 1874). Specimens from the western Himalayas (Kashmir, Nepal and Sikkim) are morphologically distinct from all other populations of and can be treated as a separate species Hodgson, 1837.