Meerkat helpers increase sentinel behaviour and bipedal vigilance in the presence of pups

Helpers in cooperatively breeding species may assist in a number of cooperative activities, such as nest building, incubating, babysitting and feeding of offspring. In addition, individuals may engage in sentinel behaviour and other forms of vigilance, which benefits other group members not only by reducing the risk of predation, but also by allowing them to reduce their own vigilance. It remains unclear, however, whether these vigilance behaviours are selfish, and the benefits to other group members simply an unselected by-product, or whether they are forms of cooperation, and the benefits to group members a selective force favouring the behaviour. In meerkats, Suricata suricatta, both female and male helpers were more likely to perform sentinel behaviour after dependent pups had started joining the group on foraging trips. In addition, female helpers performed more bipedal vigilance and found less food when pups were in the group. These results suggest that sentinel behaviour and bipedal vigilance represent forms of cooperation in meerkats.