Some Osteological Characters of Known-Age Ranch Minks

Before determining age ratios from samples of wild mink, Mustela vison, it is essential to establish some criteria for the females. A report (Lechleitner, 1954) that a supra-sesamoid tubercle was present on the femur of adults of both sexes and absent on juveniles appeared promising. The use of the baculum for distinguishing juvenile and adult males has been established (Petrides, 1950; Elder, 1951). Grateful acknowledgment is extended to Drs. Don C. Quimby and P. L. Wright for their critical review of this paper. This work is a contribution from Pittman-Robertson Research Project W-49-R, Fur Resources Survey and Investigation, Montana Fish and Game Department. Known-age ranch mink were collected principally from one Montana rancher in 1953. Supplemental adult age classes were obtained from several Montana ranchers during 1954. Eight mink ranchers supplied a total of 883 known-aged specimens: half-year, 230 males, 265 females; 1½ year,...