Reproductive success in white-tailed deer: using structural equation modeling to understand the causal relationships of MHC, age, and morphology

Abstract

Understanding factors that influence reproductive success is of utmost importance to the study of wildlife population dynamics. There are a multitude of factors that can influence a male’s ability to acquire mates, such as morphology, age, or genetic components, all of which have the potential to also influence one another. One genetic component of interest is the major histocompatibility complex (MHC). MHC genetic diversity has been linked to differences in physiology, morphology, and secondary sex characteristic production. White-tailed deer (Odocoileus virginianus) are an ideal model species for evaluating influences on reproductive success because they are a well-studied game species, they possess an easily measured secondary sex characteristic, and because of their high genetic diversity for MHC. Before we could begin analysis, we first characterized the MHC-DRB alleles present in our population. We then used structural equation modeling to examine potential causal relationships between MHC genetic diversity, morphology, age, and annual reproductive success for male white-tailed deer.