Pelage Stages in the Cottontail Rabbit

Abstract

A number of criteria have been employed to determine the age of cottontail rabbits. These include weight measurements, total length measurements, condition of the hymen in females, size of male genitalia, and ossification of epiphyseal cartilage in the bones of the forefeet. Having undertaken a study of reproduction in the cottontail rabbit, Sylvilagus floridanus mearnsi, in Ohio in 1952, I was faced with the problem of accurately aging rabbits in the field. The above methods had the disadvantage of either being impractical for field use or of not being useful in accurately aging young rabbits late in the breeding season.