Evaluation of characters for determining age of woodchucks [Evaluation des caractères de détermination de l'âge chez les marmottes américaines].

Résumé

Woodchucks (Marmota monax) captured near Chambersburg, Pennsylvania, were examined for characters that could be used to determine age. Many individuals were tagged in their first summer and recaptured in later years, thereby providing 74 known-age woodchucks. Others were classified as young-of-the -year, yearlings, or adults by using a combination of external and internal characters, such as teeth, pelage, and condition of reproductive organs. These characters permit distinction between yearlings and adults until about April 15, or later in some cases. The Weight of the lens varies linearly with age after the first year and is useful to determine the chronological age of adults.