Abstract:
Division of labour, in terms of providing for offspring, in obligate cooperatively breeding
mammalian species is poorly understood.To understand offspring provisioning in a cooperatively
breeding canid, we analysed a long-term dataset comprising 22 African wild dog,
Lycaon pictus,denning events (nine packs over nine consecutive years).We investigated the
effects of sex, age class, social status, and pack size on the likelihood and frequency of
regurgitating food to pups at the den. We found that the interaction of social status and
pack size affected the likelihood of regurgitation. Specifically, when in a large (>15) pack,
dominant individuals were less likely to regurgitate than subordinate individuals. However,
in smaller (£15) packs, dominant individuals were more likely to regurgitate than subordinate
individuals.We also found that the interaction of age and pack size affected the frequency
of regurgitation. Specifically, in large packs, yearlings regurgitated more frequently per
observation period than adults. Contrastingly, in smaller packs, adults regurgitated more
frequently.Sex did not affect pup provisioning.We suggest that these contrasting patterns of
helping are best explained by a strong selection pressure for individual behaviour that
results in larger pack sizes in this species. When in larger packs, costs are shared as the
division of labour spreads amongst individuals. In smaller packs, a division of labour
requires individuals that already experience costs (such as reproduction) to be further
burdened by provisioning. Overall, our results support that the need for more helpers to care
for offspring contributes to the evolutionary consequence of an inverse density dependence.
