Reproductive relations between animals in the hybrid settlement of the russet and yellow ground squirrels are panmictic and are characterized by the absence of assortative crossings and by the presence of multimale pairings in females with evidently heterospermic broods. Maximum breeding success was observed for hybrid animals proving the fertility of hybrids. However, the hybrid breeding potential (young animal survival rate) is significantly lower as compared with russet and yellow ground squirrels, but the survival rate of the hybrid progeny in the hybrid population is not lower than in specific settlements.