title: Social affiliation matters: both same-sex and opposite-sex relationships predict survival in wild female baboons.
abstract: Social integration and support can have profound effects on human survival. The extent of this phenomenon in non-human animals is largely unknown, but such knowledge is important to understanding the evolution of both lifespan and sociality. Here, we report evidence that levels of affiliative social behaviour (i.e. 'social connectedness') with both same-sex and opposite-sex conspecifics predict adult survival in wild female baboons. In the Amboseli ecosystem in Kenya, adult female baboons that were socially connected to either adult males or adult females lived longer than females who were socially isolated from both sexes--females with strong connectedness to individuals of both sexes lived the longest. Female social connectedness to males was predicted by high dominance rank, indicating that males are a limited resource for females, and females compete for access to male social partners. To date, only a handful of animal studies have found that social relationships may affect survival. This study extends those findings by examining relationships to both sexes in by far the largest dataset yet examined for any animal. Our results support the idea that social effects on survival are evolutionarily conserved in social mammals.
authors.affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya earchie@nd.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Archie
authors.affiliation: Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya Department of Evolutionary Anthropology, Duke University, Durham, NC, USA Duke Population Research Institute, Duke University, Durham, NC, USA Department of Biology, Duke University, Durham, NC, USA.
authors.forename: Jenny
authors.initials: J
authors.lastname: Tung
authors.affiliation: Center for Social Research, University of Notre Dame, Notre Dame, IN, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Clark
authors.affiliation: Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA Department of Veterinary Anatomy and Physiology, University of Nairobi, Nairobi, Kenya.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Altmann
authors.affiliation: Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya Duke Population Research Institute, Duke University, Durham, NC, USA.
authors.forename: Susan C
authors.initials: SC
authors.lastname: Alberts
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005260:Female; D007630:Kenya; D008136:Longevity; D008297:Male; D010215:Papio / Q000502:physiology*; D012726:Sexual Behavior, Animal; D012919:Social Behavior
keywords: intrasexual competition; longevity; social connectedness; social relationships; survival