A yellow-bellied marmot.FLICKR, MIGUEL VIEIRA
The evolutionary benefits of play are unclear, since it uses energy and may put animals in the way of predators or other threats. Play in yellow-bellied marmots has a social purpose, the authors of a recent Proceedings of the Royal Society B study argued: it helps the small mammals establish dominance hierarchies.
Yellow-bellied marmots play frequently in their first 2 years of life, and their play can be aggressive. Researchers watched marmots in Colorado near the Rocky Mountain Biological Laboratory and recorded more than 27,000 social interactions, noting incidents of play biting, chasing, and wrestling, as well as non-playful fights.
They tracked the marmots and found that the marmots’ rank during play correlated to their dominance status later in life. The authors hypothesize that play ...
