EVALUATION OF AGE-DETERMINATION TECHNIQUES FOR GRAY WOLVES

We evaluated tooth wear, cranial suture fusion, closure of the canine pulp cavity, and cementum annuli as methods of age determination for k nown- and unknown-age gray wolves (Canis lupus) from Alaska, Minnesota , Ontario, and Isle Royale, Michigan. We developed age classes for cra nial suture closure and tooth wear We used measurement data obtained f rom known-age captive and wild wolves to generate a regression equatio n to predict age based on the degree of closure of the canine pulp cav ity. Cementum annuli were studied in known- and unknown-age animals, a nd calcified, unstained thin sections were found to provide clear annu lus patterns under polarized transmitted light. Annuli counts varied a mong observers, partly because of variation in the pattern of annuli i n different regions of the cementum. This variation emphasizes the nee d for standardized models of cementum analysis. Cranial suture fusion is of limited utility in age determination, while tooth wear can be us ed to estimate age of adult wolves within 4 years. Wolves <7 years old could be aged to within 1-3 years with the regression equation for cl osure of the coming pulp cavity. Although inaccuracy remains a problem , cementum-annulus counts were the most promising means of estimating age for gray wolves.