Premise: Rana amurensis (Khabarovsk frog, Siberian wood frog, Heilongjiang brown frog or Amur brown frog) is a species of true frog found in northern Asia. It ranges across western Siberia, as well as northeastern China, northeastern Mongolia, and on the northern Korean Peninsula and on Sakhalin. "Rana coreana" was previously included in this species as a subspecies.
Hypothesis: There are more Rana amurensis in China than on Sakhalin.