Relationships between rank-related behaviour, antler cycle timing and antler growth in deer: behavioural aspects

In this review we offer a synthesis of a 30-year-long investigation focussed on the relationship between dominance rank-related behaviour and the timing and growth of antlers in deer. Our studies related primarily to red and fallow deer. We present evidence to suggest that dominance-related behaviour in male deer is strong enough to influence both antler cycle timing and antler growth. In a study on captive red deer we observed that the males of higher rank cast their antlers first and also tended to shed the velvet earlier. In a subsequent series of studies on the same species we found evidence that social position and related agonistic activity of males during the period of antler growth influence antler size and branching. Changes in behaviour related to rank modified antler growth. For example, fallow deer bucks gaining higher rank through fighting other bucks exhibited enhanced growth of that part of the antler that was growing at that particular time. That substantially altered the entire antler growth. Understanding the relationship between rank, agonistic behaviour and hormone levels is crucial for the interpretation of previous results that showed a link between dominance rank and antler growth in deer.