there are four defined taxa: o. p. "pallasi", o. p. "pricei", o. p. "sunidica", and o. "argentata". mitochondrial studies show that the two larger defined taxa of o. pallasi are paraphyletic to o. "argentata". however, morphometric data shows that the taxa o. p "pricei" and o. p. "pallasii" show similar traits to one other than to o. "argentata". o. "argentata" differ in that they show a rufous type coloration in the summer and a more silver type coloration in the winter.