The Consequences and Causes of High Social Rank in Red Deer Stags

TLDR: In a free-ranging group of male red deer on the Isle of Rhum, Scotland, that showed a strong dominance hierarchy, the consequences and causes of high social rank were investigated, suggesting that body size is important in achieving high rank.

Abstract: 1. In a free-ranging group of male red deer (Cervus elaphus L.) on the Isle of Rhum, Scotland, that showed a strong dominance hierarchy, the consequences and causes of high social rank were investigated. 2. The reproductive success that individuals achieved in the autumn mating season correlated directly with the rank that they held in the social group in the previous winter. A causal interpretation of this association is suggested by the following results. 3. Rank was not related to age or to antler length in mature stags, so these factors could not be confounding the association. 4. Rank was related to age in young stags, and to a measure of early physical development, suggesting that body size is important in achieving high rank. Body size may also independently affect rutting success. Similarly, experience of winning interactions may influence both social rank and reproductive success. However, body size and experience are likely themselves to have been affected by rank during development, contributing to divergence among individuals of the same age. 5. Rank rarely changes among individuals of the same age, so there will be lifetime differences in rank-related advantages gained.