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While strong maternal relationships have been linked with improved offspring survival in many mammals, maternal sociality appears to provide little protection against infanticidal males. Here, we evaluated whether maternal social integration predicts offspring survival to adulthood in geladas (Theropithecus gelada), a non-human primate that faces frequent alpha male takeovers coupled with high rates of infanticide. Mothers that formed stronger grooming relationships with their female and male groupmates showed higher offspring survival on average. However, when their infants experienced early-life takeovers and faced elevated infanticide risk, these survival advantages were weaker, delayed to juvenility and linked only to female–female grooming relationships. Thus, long-term social integration was not associated with reduced infanticide risk. Given this, we then examined whether females engaged in short-term social strategies that might provide more targeted protection against would-be male attackers. Following takeovers, females—particularly those with young, vulnerable infants—groomed males less frequently and prioritized deposed, protective males (i.e. their infants’ presumed fathers) over new, potentially infanticidal males. Taken together, these data suggest that gelada mothers: (i) form long-term social relationships that might improve net offspring survival and (ii) implement short-term social strategies that might protect their offspring in ways that long-term relationships cannot.
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Social integration predicts survival in female white-faced capuchin monkeys
Abstract Across multiple species of social mammals, a growing number of studies have found that individual sociality is associated with survival. In long-lived species, like primates, lifespan is one of the main components of fitness. We used 18 years of data from the Lomas Barbudal Monkey Project to quantify social integration in 11 capuchin (Cebus capucinus) groups and tested whether female survivorship was associated with females’ tendencies to interact with three types of partners: (1) all group members, (2) adult females, and (3) adult males. We found strong evidence that females who engaged more with other females in affiliative interactions and foraged in close proximity experienced increased survivorship. We found some weak evidence that females might also benefit from engaging in more support in agonistic contexts with other females. These benefits were evident in models that account for the females’ rank and group size. Female interactions with all group members also increased survival, but the estimates of the effects were more uncertain. In interactions with adult males, only females who provided more grooming to males survived longer. The results presented here suggest that social integration may result in survival-related benefits. Females might enjoy these benefits through exchanging grooming for other currencies, such as coalitionary support or tolerance.
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- PAR ID:
- 10368622
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Behavioral Ecology
- Volume:
- 33
- Issue:
- 4
- ISSN:
- 1045-2249
- Page Range / eLocation ID:
- p. 807-815
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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