Strong and consistent social bonds enhance the longevity of female baboons.
Longevity is a major component of variation in fitness in long-lived iteroparous species [1-4]. Among female baboons, variation in breeding lifespan accounts for approximately 50% of the variation in lifetime fitness [5, 6]. However, we know little about the causes of variation in longevity in primates or other long-lived mammals. Savannah baboons form strong, equitable, and enduring relationships with specific female partners, particularly with close relatives and agemates [7-10]. The quality of females' social relationships influences their ability to cope with stressful events [11-13] and is associated with variation in female reproductive success [9, 14]. Here we show that dominance rank and the quality of close social bonds have independent effects on the longevity of female chacma baboons (Papio hamadryas ursinus). High-ranking females live longer than lower-ranking females. In addition, females who form stronger and more stable social bonds with other females live significantly longer than females who form weaker and less stable relationships. These data extend our understanding of the adaptive value of social bonds in baboons and complement a growing body of evidence that indicates that social bonds have adaptive value in a range of taxa, from mice to humans [9, 14-19].
Silk
Joan B
JB
Department of Anthropology, University of California-Los Angeles, CA 90095, USA. joansilk@gmail.com
Beehner
Jacinta C
JC
Bergman
Thore J
TJ
Crockford
Catherine
C
Engh
Anne L
AL
Moscovice
Liza R
LR
Wittig
Roman M
RM
Seyfarth
Robert M
RM
Cheney
Dorothy L
DL
D000818:Animals; D005260:Female; D008136:Longevity; D009769:Object Attachment; D048529:Papio hamadryas / Q000523:psychology*; D012930:Social Dominance