Validity of Horn Segment Counts in Aging Bighorn Sheep

Abstract

Horn segment counts were compared with chronological age of 21 bighorn rams (Ovis canadensis) of known age, and were found to coincide. Investigators of population dynamics of bighorn sheep have relied on counts of horn segments to determine age (Murie 1944, Blood 1961, Sugden 1961, Welles and Welles 1961, Woodgerd 1964). The validity of this method has not been established. During a study of bighorn behavior in Banff National Park, Alberta, I was able to test the method with a bighorn population containing tagged individuals of known