The factors affecting the stag social hierarchy and antler cycle timing in a herd of red deer were analysed. The analysis was based on behaviour records of the herd between 1972 and 1983.
The alpha stag was not usually the oldest stag present. Changes in rank were commoner in periods of hard antler than during velvet periods. The frequency of rank changes was correlated with the number of stags present but not with the number of hinds; it was also positively related to indicators of the level of aggression such as the incidence of antler breakage, the number of harem-holding stags per rut and the incidence of post-casting rank loss. The number of stags killed in fights was not correlated to any of the indicators of aggression except the number of harem-holders per rut.
Rank loss after antler casting and the change of harem-holding stags during the rut were both relatively rare events indicating year-round, stable social relationships in the herd.
The relationships between rank and casting date and between rank and cleaning date previously reported were related to the level of aggression among the deer. The higher the level of aggression, the closer the relationship between rank and the timing of the antler cycle. The small difference in the level of aggression between the periods of casting and cleaning is thought to be the result of the seasonally different social background.
The number of hinds present did not appear to affect antler casting, antler cleaning or the general indicators of the level of aggression. It is concluded that the results support the previously advanced hypothesis that behaviour modulates antler cycle timing in Cervids.