Ontogeny of alarm call responses in meerkats, Suricata suricatta: the roles of age, sex and nearby conspecifics

Given the strong selection on prey animals to escape predation, early development of correct avoidance strategies should be favoured. We studied the development of responses to conspecific alarm calls in a free-ranging population of meerkats in South Africa. Through behavioural observations of naturally occurring predator encounters and playback experiments, we monitored responses of young individuals from emergence (3 weeks) to 6 months of age and compared them with those of adults (>12 months). Although the total proportion of responses differing from those of adults was low during the observed period, the probability of responding like adults increased with age. Female young, who remained in closer contact to adults than did male young, were also more likely to show adultlike responses. The largest proportion of non-adultlike responses was shown before reaching independence at 3 months of age, and during this time young commonly ran immediately to a nearby individual when hearing an alarm call. After playbacks of alarm calls, young also reacted more slowly, resumed foraging sooner and spent less time vigilant than did adults. We conclude that young may need experience during early development to associate an alarm call correctly with the type of threat and appropriate response. Older group members may also serve as indirect models, perhaps helping young to form this association.