Factors influencing reproductive success in male white‐tailed deer

Positive relationships between age, sexually selected traits, and male reproductive success have been reported for a number of polygynous ungulates; however, relatively little is known about the factors influencing male reproductive success in ungulate species whose mating system is characterized by tending-bond behaviors. Broad interest in the genetic consequences of selective harvest supports a greater understanding of the role of these factors as determinants of male reproductive success in important game species (e.g., white-tailed deer [Odocoileus virginianus]), that exhibit tending-bond behaviors. We investigated male reproductive success in white-tailed deer across a range of sex ratios and age structures using a known population of deer housed in a 175-ha enclosure in central Alabama, USA. We measured age, annual antler size, and annual body size of male white-tailed deer and assigned paternity to 143 known-age offspring during 2007–2014. Reproductive success was attributed to a high proportion of males during each of the 6 breeding seasons. Our most supported model indicated that annual body size and antler size of the individual were positively associated with annual male breeding success. The effects of annual antler size were sensitive to changes in mean male age of the herd, with antler size having the greatest effect on male reproductive success under older male age structures. Young (≤1.5 yr) males reproduced most frequently when male age structure was youngest (which correlated with female-biased sex ratios in this population). Our results suggest that male age structure and sex ratio played a key role in establishing patterns of male reproductive success in white-tailed deer. Management practices that encourage balanced adult sex ratios and older male age structures (e.g., Quality Deer Management) may promote a highly competitive environment where sexually selected traits are of increased importance to male breeding success. However, the ability of managers to alter herd genetics in a positive or negative direction through selective harvest is limited in white-tailed deer because of the high proportion of reproducing males. © 2016 The Wildlife Society.