Biology_of_Mustelids_Vol_1.pdf

15.
constriction is 1.0-3.0 mm (M. 1.8) in the male and '0.5-2.0 mm (M.1.4)
in the female.
Geographical distribution.
Southern and South-Eastern parts of the
region beyond Lake Baikal, North-Eastern Mongolia.
Remarks on taxonomy.
The weasel from beyond Lake Baikal is identical
with the M~ngolian weasel. It has the same bright colouring, small
dimensions and short tail.
Its dimensions are very nearly the same as
those of Mustela nivalis pygmaea, the principal difference from that
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species being its colouring. There' is a slight difference between the
skulls. The skull of ~. ~. punctata is wider in the rostral region, with
a more abrupt postorbital constriction, and the sexual dimorphism is less
well defined. In winter the weasel from beyond Lake Baikal turns white.
The coats of the two winter weasels from Mongolia and the region beyond
Lake Baikal (in the Academy of Sciences ZIN collection and the Moscow State
University Zoological Museum collection) were pure white. A specimen
(5-43828) from Mongolia had a very narrow band of bright brownish fur
along the spine and head, and a broad white area stretching up to the sides
and spine (March). The animal was obviously changing from its winter white
(a)
coat to its bright brownish summer coat. The September and October
specimens had bright brownish or pale brownish coats with no trace of
change of coat colour.
GROUP II: "BOCCAMELA" GROUP WEASELS
Very large weasels with a long tail and a large skull.
Distribution: the region beyond the Caucasus, the flat plains of Western
Kazakhstan and Central Asia from the Caspian Sea to Semirech'e.
(a) The weasel follows the same moult pattern as the stoat, which is
well illustrated by van Saest and van Bree (1969). - Ed.