Aggressive behaviour, sexual strategies and their relation to age in male Spanish ibex (Capra pyrenica )

This study aimed to investigate the factors determining male reproductive success during the rutting season of the Spanish ibex. The rut lasts about seven weeks. At the begining of this period the old males engage in contests with each other, while the adult and subadult males spend more time courting the females. In the second half of this period, the old males court and gain reproductive acceptance while the adult and subadult males decrease their courtship activity. The old males also differ from the adult and subadults in the daily pattern of courtship activity. The old males test their relative strength and show agonistic displays as their most typical behaviour, while younger males tend towards more overt and primitive forms of fighting. Most contests involving males of all age classes occur between animals of similar age and these combats often end unresolved. The older of two combatants usually wins. Older males are preferred to younger ones by the females. The older the males, the more energy they expend in activities leading to mating and representing energy expenditure and the less time they use in those representing energy saving or recovery.