How Cooperation Can Trump Competition in Monkeys

http://www.sciencedaily.com/releases/2012/07/120704021831.htm

ScienceDaily (July 4, 2012) — Being the top dog -- or, in this case, the top gelada monkey -- is even better if the alpha male is willing to concede at times to subordinates, according to a study by researchers from the University of Pennsylvania, the University of Michigan and Duke University.

Alpha male geladas who allowed subordinate competitors into their group had a longer tenure as leader, resulting in an average of three more offspring each during their lifetimes.

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To understand why potential rivals might team up, researchers compared the fitness consequences for dominant male gelada monkeys living in single- or multi-male groups. They found that, although subordinate males father some of the offspring in multi-male groups, dominant males gain a lifetime fitness benefit because the subordinate aids in defense of the group from other males, thus extending the dominant male's reproductive career.