title: Low female stress hormone levels are predicted by same- or opposite-sex sociality depending on season in wild Assamese macaques.
abstract: The social environment can have a powerful impact on an individual's stress response and thus affect health and biological fitness. Positive social interactions are particularly important for females of species living in complex societies, e.g. humans and non-human primates. Existing studies have mainly focussed on the effect of same-sex social interaction on the stress response, rather than both same- and opposite-sex social interaction simultaneously. However, consideration of both may be crucial since females may have different 'social needs' across different life-history stages. Applying the conceptual framework of allostasis, we tested the hypothesis that female allostatic load (measured through faecal glucocorticoid levels [fGCs]), of wild seasonally breeding Assamese macaques (Macaca assamensis), would increase if their social needs were not maintained in accordance with season. We found significant seasonal differences in same- and opposite-sex sociality which, depending on season, predicted female fGCs. In the mating season, females which spent more time close to males and more frequently groomed with them exhibited lower fGCs. In the non-mating season, when female-male interaction was infrequent, positive female-female sociality predicted lower fGCs. Our results support the hypothesis that same- and opposite-sex sociopositive interactions, specific to certain life-history stages, can mediate fGCs. We interpret this as a consequence of the positive direct and/or indirect effects of social contact in accordance with interactions pertaining to a given life-history stage, which are likely to impact positively upon fitness.
authors: Primate Social Evolution Group, Courant Research Centre Evolution of Social Behaviour, Georg-August-University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany. Electronic address: i.fuertbauer@swansea.ac.uk.
authors: Ines
authors: I
authors: Fürtbauer
authors: Endocrinology Laboratory, German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany.
authors: Michael
authors: M
authors: Heistermann
authors: Courant Research Centre Evolution of Social Behaviour, Georg-August-University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.
authors: Oliver
authors: O
authors: Schülke
authors: Primate Social Evolution Group, Courant Research Centre Evolution of Social Behaviour, Georg-August-University Göttingen, Kellnerweg 6, 37077 Göttingen, Germany.
authors: Julia
authors: J
authors: Ostner
mesh_terms: D000818:Animals; D000835:Animals, Wild; D005043:Etiocholanolone / Q000032:analysis / Q000378:metabolism; D005243:Feces / Q000737:chemistry; D005260:Female; D006120:Grooming; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism*; D008251:Macaca / Q000378:metabolism / Q000523:psychology; D008297:Male; D012621:Seasons; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012919:Social Behavior; D012930:Social Dominance; D012931:Social Environment; D013312:Stress, Physiological
chemical_list: D005043:Etiocholanolone; D006854:Hydrocortisone
keywords: Allostatic load; Female–female sociality; Female–male sociality; Life-history stage; Macaca assamensis; Seasonal reproduction; Social environment; Stress physiology