Competition-induced stress does not explain deceptive alarm calling in tufted capuchin monkeys

摘要: Tactical deception has long attracted interest because it is often assumed to entail complex cognitive mechanisms. However, systematic evidence of tactical rare and no study attempted determine whether such behaviours may be underpinned by relatively simple This examined deceptive alarm calling among wild tufted capuchin monkeys, Cebus apella nigritus, feeding on contestable food resources can potentially explained a physiological mechanism, namely increased activation in the adrenocortex resulting production glucocorticoids (GCs; ‘stress hormones’). was tested experimentally Iguazu National Park, Argentina, manipulating potential for contest competition over noninvasively monitoring GC through analysis faecal hormone metabolites. If false alarms are indeed associated with adrenocortical activity, predicted that patterns these calls would match output, generally being higher callers than noncallers cases which most contestable, specifically those occasions when produced. hypothesis not supported, as (1) output significantly lower association experimental introduction natural contexts wherein lower, (2) within contexts, there nonsignificant tendency show (3) individuals did levels they produced relative not. A learned between access likely explanation this case deception, although unexplored mechanisms also remain possible.