Longevity of the Short-tailed Shrew

Abstract

Tooth-wear is a reliable indicator of age in wild specimens of Blarina brevicauda. Shrews more than 2 yrs. old would be practically toothless. The age limitation imposed by tooth-wear is more potential than actual, for few shrews survive until the teeth are badly worn. Scarcity of old shrews in winter can be partly accounted for by dilution of the old by numerous progeny. Six % of winter specimens were old; 2 specimens apparently survived 2 winters. Six % of summer-banded shrews were recaptured the following summer, and 4% of the marked deer-mice. Captive shrews lived up to 33 months. The popular assumption that shrews die of old age or some mysterious cause in the autumn is at present unwarranted. Proof is lacking of any essential differences in the regulation of life span of short-tailed shrews, deer-mice, and perhaps other small, prolific mammals.