Sex ratio of a population of Anatolian ground squirrelsSpermophilus xanthoprymnus in Central Anatolia, Turkey

We studied the sex ratio of a population of Anatolian ground squirrels,Spermophilus xanthoprymnus (Bennett, 1835), living in a steppe area about 50 km south of Ankara, Central Anatolia, Turkey in 1999–2001. The sex ratio among juveniles and yearlings did not differ from 1∶1, but the sex ratio among adults (≥ 2 years old) was biased toward females. We concluded that from their second summer of life as yearlings onwards, males experienced higher mortality than did females. Such higher mortality is common in ground squirrels, and is likely due to the risks encountered when males disperse from their natal areas.