Offspring food allocation by parents and helpers in a cooperative mammal

Abstract

In cooperatively breeding species, helpers and parents commonly face two decisions when they find a food item: first, whether to feed the item to a young group member or to eat it themselves; and second, which offspring to feed. Little is known about the factors that influence these decisions in cooperative mammals, though optimal foraging theory provides a basis for a range of predictions. In this article we describe pup feeding behavior by helpers and parents in a cooperative mongoose, the meerkat (Suricata suricatta). When meerkat pups begin accompanying the group, they beg food from older group members, who dig up dispersed prey items. As predicted, the probability of a prey item being fed to a pup shows a positive relationship with prey size and a negative relationship with pup distance. Meerkats apparently follow a ‘‘feed the nearest pup rule’’ and are more likely to feed the nearest pup if it is hungry. Hungrier pups beg more and follow older group members more closely. Across all age categories, females feed pups more frequently than males, both in terms of the relative frequency of feeds, and the proportion of prey biomass found by each individual that is fed to pups. Females also feed female pups significantly more than male pups, while males feed pups of both sexes equally. These sex biases in feeding contributions may result from female group members benefiting more than males from higher pup survival, and in particular higher female pup survival, because females are the philopatric sex. Key words: cooperative breeding, group augmentation, kin selection, meerkat, offspring feeding rules, sex-biased parental care. [Behav Ecol 12:590–599 (2001)]