Effects of antler breakage on mating behavior in male tule elk (Cervus elaphus nannodes)

Although antler size has been identified as a primary determinant of dominance, fighting success, and reproductive success in male cervids, >80% of the male tule elk (Cervus elaphus nannodes) in the Owens Valley, California, experience antler breakage. To determine the effect of antler breakage on male mating success, we recorded antler morphology, body size, and mating behavior of male elk throughout the rut. Antler breakage, regardless of severity, had no effect on male-male assessment, fighting success, or harem-holding status. The factor consistently associated with our indices of male mating success was not antler size but body size. Although antler size is frequently emphasized as a key factor in male dominance and social rank, this association may reflect the correlation between antler size and body size. In the Owens Valley, it appears that male elk are not assessing competitors based on antler morphology but on other characteristics.