Antler Size Provides an Honest Signal of Male Phenotypic Quality in Roe Deer

Abstract

Identifying factors shaping secondary sexual traits is essential in understanding how their variation may influence male fitness. Little information is available on the allocation of resources to antler growth in territorial ungulates with low sexual size dimorphism. We investigated phenotypic and environmental factors affecting both absolute and relative antler size of male roe deer in three contrasting populations in France and Sweden. In the three populations, we found marked age-specific variation in antler size, with an increase in both absolute and relative antler size between yearling and prime-age stages, followed by a decrease (senescence) for males older than 7 years. Antler size increased allometrically with body mass. This increase was particularly strong for senescent males, suggesting the evolution of two reproductive tactics: heavy old males invested particularly heavily in antler growth (potentially remaining competitive for territories), whereas light old males grew small antlers (potentially abandoning territory defense). Finally, environmental conditions had little effect on antler size: only population density negatively affected absolute antler size in one of the three populations. Antler size may therefore provide an honest signal of male phenotypic quality in roe deer. We discuss the implications of these results in terms of territory tenure and mating competition.

Direct and indirect causal effects of heterozygosity on fitness-related traits in Alpine ibex

“…Body mass and horn growth have an effect on the dominance status of male Alpine ibex [64], and therefore probably contribute to reproductive success [72]. Secondary sexual traits are also known to be honest signals of individual quality [58,73]. Gastrointestinal parasites, as well, have a crucial role in the life history and survival of wild herbivores, and create repercussions on Figure 2.…”

Defining individual quality over lifetimes and selective contexts

“…Most notably, the meaning of 'quality' frequently depends on whether the studies concerned are couched in behavioural, ecological, or evolutionary perspectives [1]. Within an evolutionary and sexual selection framework, for example, genetic quality is considered to be breeding value for total fitness [2]; behavioural studies, however, generally regard quality to be a specific trait or suite of traits that maximizes fitness (or correlates thereof ) within a specific context, such as female choice or intrasexual competition [3]; while in ecological studies, quality is considered to comprise traits that maximize lifetime reproductive success [4,5].…”

Changes of the testes parameters, carcasses and antlers mass of harvested roe deer (Capreolus capreolus) bucks

“…Komosa et al (2013) evaluated changes in carcass mass and antler mass in Testes, carcasses and antlers parameters of roe deer bucks 1249 the roe deer in three consecutive years and observed a medium correlation between those variables (r = 0.43). Vanpé et al (2007) reached a more radical conclusion, stating that only the heavy bucks can afford long, costly antlers.…”