Geology topics
R. M. Nowak
Publications and source records attributed to R. M. Nowak.
Accuracy and precision of estimating age of gray wolves by tooth wear
We evaluated the accuracy and precision of tooth wear for aging gray wolves ( Canis lupus ) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skulls. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionally by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within ± 1 year of actual age, but under estimated ages of wolves ≥ 9 years old by 1-3 years. No differences were detected in tooth wear patterns for wild wolves from Alaska, Minnesota, and Ontario, nor between captive and wild wolves. Tooth wear was not appropriate for aging wolves with an underbite that prevented normal wear or severely broken and missing teeth.
Return of the gray wolf to Wisconsin
Five gray wolf ( Canis lupus ) specimens were examined from Wisconsin from 1975 through 1979; each had been killed by human beings, accidentally or intentionally. This confirms the presence of wolves in Wisconsin and supports the hypothesis that human-related mortality is the factor limiting the population.