Publication
Producers and scroungers: feeding-type composition changes with group size in a socially foraging spider
Publisher:
The Royal Society
Date:
13-04-2016
DOI:
10.1098/RSPB.2016.0114
Abstract: In groups of socially foraging animals, feeding behaviour may change with group size in response to varying cost–benefit trade-offs. Numerous studies have described group-size effects on group-average feeding behaviour, particularly emphasizing an increase in scrounging incidence for larger groups, where in iduals (scroungers) feed from the food sources others (producers) discovered. However, in idual variation in feeding behaviour remains unconsidered in the vast majority of these studies even though theoretical models predict in iduals to specialize in feeding tactic and anticipate higher scrounger-type frequencies in larger groups. We combined group-level and in idual-level analyses of group-size effects on social foraging in the subsocial spider Australomisidia ergandros . Lending novel experimental support to model predictions, we found that in iduals specialize in feeding tactic and that higher scrounging and lower producing incidence in larger groups were mediated through shifts in the ratio of feeding types. Further, feeding-type specialization was not explained by innate in idual differences in hunting ability as all feeding types were equally efficient in prey capture when foraging alone. Context adaptivity of feeding behaviour might allow this subsocial species to succeed under varying socioecological conditions.