Formal submission, tolerance and socioecological models: a test with female Hanuman langurs

Patterns of agonistic relationships among group-living mammalian females are suggested to reflect differences in feeding competition. Socioecological models predict that within-group contest (WGC) competition leads to despotic relationships that are linear, consistent, and stable, in which subordinate individuals use formal submission to acknowledge rank. Between-group contest ( BGC) competition and risk of infanticide are predicted to add tolerance, as evidenced by frequent reconciliation, low-intensity aggression and counteraggression. We examined the predicted effects for formal submission and two criteria of tolerance for a group of Hanuman langurs ( Semnopithecus entellus) in a population known to experience WGC and BGC as well as high rates of infanticide. Results were based on focal animal sampling of eight of 13 adult females ( 419 h) and ad libitum sampling of all 13 females ( 711 contact hours) in the group Kailana I ( Jodhpur, India). The behaviour 'presenting' ( N= 281) qualified as formal submission, adhering to most proposed criteria ( e. g. linear, consistent, predictive of other agonistic relationships and hierarchies, 40.9% spontaneous). Thus, regarding formal submission, the predicted effects of WGC hold, and support the explanatory value of this aspect of socioecological models. In contrast, agonistic relationships were nontolerant, with frequent high-intensity aggression ( 48.9% of N= 231) and almost no counteraggression (< 1%). This suggests that either the criteria used in assessing BGC require reconsideration or the predicted effects of BGC on tolerance should be revisited. The latter adds to growing evidence of BGC as a weak predictor of within-group relationships. (c) 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.