The ability of male chimpanzees to form coalitions with one another in order to direct aggression at other male chimpanzees has certain benefits. A new study by Ian Gilby at Duke University in North Carolina and his colleagues has further revealed that it may not just be the coalition that is important, but who the coalition is with that determines future success. Their study finds that male chimpanzees with central positions in the coalitionary network were most likely to father offspring and increase in rank. Specifically, those who formed coalitions with males who did not form coalitions with each other were the most successful. Their work is published in the Springer journal Behavioral Ecology and Sociobiology.
Coalitionary aggression is when at least two individuals jointly direct aggression at one or more targets. Aggression and coalition formation between males is important for attaining a higher dominance in many animal species. The most dominant males are more likely to mate and therefore, sire offspring. Males with high coalition rates are more likely to mate more often than expected for their rank.
Gilby and his colleagues studied data from wild chimpanzees gathered over 14 years from the Kasekela community in Gombe National Park in Tanzania. They wanted to test the hypothesis that male coalitionary aggression leads to positive benefits via increased dominance rank and improved reproductive success. Of the four measures they used to characterize a male's coalitionary behavior, the only one that was related to both of these factors was 'betweenness' – a measure of social network centrality – which reflects the tendency to make coalitions with other males who did not form coalitions with each other. The only non-alpha males to sire offspring were males that had the highest 'betweenness' scores. These males were also more likely to increase in rank, which is associated with higher reproductive success.
The researchers postulate that this shows that male chimpanzees may recognize the value of making the 'right' social connections. By choosing their coalition partners carefully, they are demonstrating an ability to recognize the relationships of others.
The authors conclude that "…our data suggest that there are consequences to the recognition of third party relationships. As such, it represents an important step toward a more complete understanding of the adaptive value of social intelligence and the evolution of co-operation." They add that further observation is required to fully explain the study's findings.
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
An innate ability some people have to manipulate their vocal frequency could be the key to sounding charismatic, according to new research.
Time-lapse imagery of scavengers tucking in proves that dead jellyfish aren't unpalatable after all, so can return nutrients to the sea's food webs
When bird pairs break up females often lay more eggs with a new partner, but the split can be disastrous for the male of the species
Spontaneous gene mutations, not ones inherited from parents, increase a child's risk of autism, scientists say. By comparing genes within families they've identified more than 100 suspects.
Slovenian archaeologist Ivan prajc is behind discovery of three significant ruins in the remote jungles of the Yucatán peninsula
Every year, Nikon selects the most artful, scientifically enlightening and skillfully produced images from thousands of submissions for its Small World microscope photography contest. Tomorrow, another set of impressive winners will be announced for the contest’s 40th year.
Seaview divers routinely cover 2 kilometers in a dive and generate 3,000 panoramic images in a day. Only a fraction of the best are uploaded to Google Street View.
Meeting sharks can be a moving experience, says photographer Jean-Marie Ghislain, who works to educate people on the plight of sharks around the world
From kraken to mermaids, some monsters are real—if you know how to look for them
Australia's Academy of Science says a government draft plan to protect the Great Barrier Reef will not prevent its decline.