Mating strategies of male feral goats: a problem in optimal foraging

Among feral goats, Capra hircus, on the Isle of Rhum, Scotland, the highest ranking males are able to monopolize a disproportionate share of the access to females in oestrus. Since oestrous females are an unpredictable, patchily distributed resource, a male who is prevented from mating by more dominant rivals faces a choice between (1) staying on in the group in the expectation that, sooner or later, other females will come into oestrus and (2) leaving to search for a group that contains fewer dominant males. A model of the male's decision is developed which shows that males adjust their willingness to join and leave groups in response both to the number of oestrous females they can expect to find in a group and to the number of competing males in the group. There is some evidence to suggest that the skill with which a male exploits the situation improves with age and experience. © 1990 The Association for the Study of Animal Behaviour.