Using biological markets principles to examine patterns of grooming exchange in Macaca thibetana

摘要: Biological markets principles offer testable hypotheses to explain variation in grooming exchange patterns among nonhuman primates. They predict that when within-group contest competition (WGC) is high and dominance hierarchies steep, interchange with other “commodity” behaviors (such as agonistic support) should prevail. In contrast, WGC low gradients shallow, market theory predicts reciprocity We tested these predictions a wild, provisioned Tibetan macaque (Macaca thibetana) group across six time periods during which the had been subjected varying degrees of range restriction. Data on female–female aggression, grooming, support were collected using all-occurrences focal animal sampling techniques, analyzed ANCOVA methods correlation analyses. found hierarchical steepness varied significantly periods, but did not correlate two indirect indicators (group size restriction) predicted directions. Contrary expectations, we negative between size, perhaps because responses members external risks (i.e. prolonged unavoidable exposure humans) may have overshadowed effects WGC. As predicted, was significant each period negatively correlated steepness, even after controlled kinship, rank differences, proximity. there no evidence for or positive relationship steepness. hypothesize stressful conditions and/or presence stable led greater demand than support. suggest future studies testing consider more direct measures commodities addition support, such feeding tolerance access infants. Am. J. Primatol. 73:1269–1279, 2011. © 2011 Wiley Periodicals, Inc.