| Scope and method of study. The purpose of this study was to determine if mating systems of adult, male white-tailed deer ( Odocoileus virginianus) follow patterns predicted by the immunocompetence handicap hypothesis. We gathered data deer during 1994–1997 at the McAlester Army Ammunition Plant in southeastern Oklahoma and examined relationships between antler development, the major histocompatibility complex, parasite loads, morphometrics, and physiological parameters. We also examined mortality patterns of adult, male deer to determine if they conformed to mate competition theory.;Findings and conclusions. Relative fluctuating asymmetry of antlers was related negatively to antler size within all age classes, except deer ≥6.5 years of age, where a positive relationship was detected. Relative asymmetry also was related negatively to carcass mass, inside spread, skull length, and body length. Mean abundance and intensity of Haemonchus contortus were strongly associated with phylogenetic groupings of Odvi-DRB alleles. Abundances and intensities of Apteragia odocoilei, Ostertagia mossi, and O. dikmansi were weakly associated with Odvi-DRB phylogenetic groupings. Infection of ectoparasitic ticks was strongly associated with Odvi-DRB alleles from a different lineage than abomasal nematodes. We detected positive associations between Odvi-DRB heterozygosity and antler development and body mass. Individuals that were heterozygous at Odvi-DRB had greater levels of serum testosterone. We observed a negative relationship between degree of antler development and overall abundance of abomasal helminths. Annual rates of mortality were stable throughout adulthood (0.26–0.38), but causes of mortality changed with age. Young males (1.5–2.5 years old) were most susceptible to human-induced mortality whereas males ≥3.5 years old tended to die from natural causes. Antler characteristics of deer in our study followed patterns predicted for a trait that is selected for by females, however we did not examine female choice. Relationships between antlers and the MHC support the hypothesis that antler development in white-tailed deer is an honest signal of quality. Furthermore, these data suggest that allelic composition of the Mhc-DRB may represent a genetic trade-off, and heterozygosity between allelic lineages may provide resistance to a greater diversity of pathogens. |
