title: Successful hunting increases testosterone and cortisol in a subsistence population.
abstract: Controversy over the adaptive significance of male hunting in subsistence societies hinges on the relative importance of familial provisioning and mate-quality signalling. This paper examines the proximate and ultimate motivations of hunting behaviour from a neuroendocrine perspective, using salivary testosterone and cortisol data collected before, during and after hunting focal follows from 31 Tsimane hunters aged 18-82 years. Despite circadian declines in hormone levels, testosterone and cortisol of Tsimane hunters increased at the time of a kill, and remained high as successful hunters returned home. Previous studies of hormonal changes during competitions find that high-stakes and success in the presence of relevant audiences result in increased neuroendocrine arousal. If men hunt primarily to provision their families, then an additional audience would not be expected to impact testosterone or cortisol, nor would the size of the animal killed. However, if signalling male quality by 'showing off' was a larger relative driver of men's hunting behaviour, one would expect greater hormonal response in cases where men returned with large sharable kills, especially in the presence of community members. Consistent with provisioning models of male hunting motivation, neither kill size nor encountering an audience of villagers while returning from hunting was associated with hormonal changes for successful hunters.
authors: Institute for Social, Behavioral, and Economic Research, University of California Santa Barbara, , Santa Barbara, CA 93106-3210, USA, Integrative Anthropological Sciences, Department of Anthropology, University of California Santa Barbara, , Santa Barbara, CA 93106-3210, USA, Department of Anthropology, University of Washington, , Seattle, WA, USA, Center for Studies in Demography and Ecology, University of Washington, , Seattle, WA, USA, Department of Anthropology, University of New Mexico, , Albuquerque, NM, USA.
authors: Benjamin C
authors: BC
authors: Trumble
authors: Eric A
authors: EA
authors: Smith
authors: Kathleen A
authors: KA
authors: O'Connor
authors: Hillard S
authors: HS
authors: Kaplan
authors: Michael D
authors: MD
authors: Gurven
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001838:Bolivia; D005006:Ethnicity; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009042:Motivation / Q000502:physiology*; D012463:Saliva / Q000737:chemistry*; D012919:Social Behavior; D013739:Testosterone / Q000032:analysis*
chemical_list: D013739:Testosterone; D006854:Hydrocortisone
keywords: Tsimane; cortisol; costly signalling; household-provisioning; hunting; testosterone