Cooperation, Competition, and Killing: Reproductive strategies of chimpanzees (Pan troglodytes)
2023-08
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
Cooperation, Competition, and Killing: Reproductive strategies of chimpanzees (Pan troglodytes)
Authors
Published Date
2023-08
Publisher
Type
Thesis or Dissertation
Abstract
Group-living commonly involves tensions between conflict and cooperation. Group members need one another to survive, but also compete for access to key resources such as food and mates. To better understand reproductive strategies in group-territorial species with sex-biased dispersal, I used decades of data from Gombe National Park, Tanzania to test hypotheses regarding how and why chimpanzees (Pan troglodytes) cooperate, compete, and fight. First, I found that male chimpanzees exhibit a consistently high degree of participation in boundary patrols (mean=75%) and that the best predictors of participation in patrols were sighting frequency and participation in hunting bouts, indicating a mutualistic payoff structure for male territorial effort. Second, I found that female chimpanzees produced copulation calls more frequently when they were nulliparous, and in the early days of their swelling. Thus, these calls likely function as an anti-infanticide strategy, inducing otherwise uninterested males to mate and maximizing the pool of potential sires. Females also called less frequently in the presence of higher-ranking females, indicating that intrasexual competition plays a role in call production. Third, I found that males killed by other chimpanzees suffered a higher-than-expected rate of genital wounding, but during non-fatal fighting, only in one of four communities (Kasekela) did males experience a higher-than-expected rate of genital wounds. Females in all four study communities experienced a higher-than-expected rate of genital wounds, indicating that genital wounding is an unlikely alternative to lethal aggression. Finally, I found that lethal aggression was more common in Mitumba than Kasekela. As a smaller community, Mitumba has fewer females and thus less overlap between reproductively active females and a greater opportunity to monopolize mating opportunities. Overall, this work emphasizes the importance of within-group reproductive competition.
Keywords
Description
University of Minnesota Ph.D. dissertation. August 2023. Major: Ecology, Evolution and Behavior. Advisor: Michael Wilson. 1 computer file (PDF); xiv, 194 pages.
Related to
Replaces
License
Collections
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Massaro, Anthony. (2023). Cooperation, Competition, and Killing: Reproductive strategies of chimpanzees (Pan troglodytes). Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/259772.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.