One of my biggest questions nearing the end of my semester of Animal Behavior class was “Why do animals play?”. Play behavior is a widespread occurrence in mammals, and good pet owners and zookeepers are always sure to make sure to play with their animals or offer them some kind of enrichment object. But at first glance, play seems like a useless activity. It takes up a lot of time and energy in some cases; energy that could be spent finding food or caring for young. It can also result in injury if play gets rough or the environment is treacherous, and playing animals may not be aware of approaching dangers. Certainly there must be a great benefit in play that overcomes all of these risks. In my research, wasn’t at all surprised to find that I wasn’t the first to ask this question, but I was surprised to find that there seems to be no definite answer.
Its widely accepted that play is beneficial in human beings. Mimicking adults in games such as “house” and using toy kitchens and dolls helps children to learn household skills. Playing sports help build muscle, bodily coordination, hand-eye coordination, and cooperation skills through teamwork. Many social skills are built through play. There are clear examples of humans benefiting from play, but what about in other animals?
Studies in both meerkats and grasshopper mice show that play in youngsters doesn’t really have any effect on factors like foraging ability and fighting skills. Strangely enough, in these animals, play doesn’t appear to have any purpose (yet).
There are lots of studies though, that show benefits of play in different species.Young brown bears who play more have a better chance of surviving out on their own away from their mother. Ground squirrels who played more successfully reared more pups and had improved motor skills and coordination, according to one study.
Rats (well known for their playfulness) who did not get to play with littermates in the lab were found to lack social skills and responded aggressively to others in social situations. When they played for even just an hour a day, they became much more relaxed.Other studies show that rats who play more have more well developed brains. Rats also laugh and leap for joy when they are tickled, which could suggest that they have evolved neurological mechanisms that reward them for playing and having fun. This makes sense in the context of healthy brain growth.
It has been proposed that play is a way to counter stress. If animals have neurological rewards for play like rats (and humans) do, then playing could help reduce stress levels and improve health. This, combined with other explanations above, could explain why it is observed in not only throughout the mammals, but other creatures such as caimans and octopuses.
So, in my search for answers about play, I found some answers, but also a whole new set of questions. I suppose I will have to continue to search into the future as more and more research is done on this perplexing animal behavior. 🐾
So You Think You Know Why Animals Play… by Lynda Sharpe May 17, 2011 https://blogs.scientificamerican.com/guest-blog/so-you-think-you-know-why-animals-play/
Social play behaviours and insect predation in northern grasshopper mice (Onychomys leucogaster) by Vicki A. Davies and Ernest D. Kemble, 1983. http://www.sciencedirect.com/science/article/pii/0376635783900086#
Play behaviour and multi-year juvenile survival in free-ranging brown bears, Ursus arctos by Robert and Johanna Fagen, 2009. https://www.researchgate.net/publication/273135416_Play_behaviour_and_multi-year_juvenile_survival_in_free-ranging_brown_bears_Ursus_arctos
Juvenile social play and yearling behavior and reproductive success in female Belding’s ground squirrels. Nunes, S. J Ethol (2014) 32: 145. doi:10.1007/s10164-014-0403-7 http://link.springer.com/article/10.1007%2Fs10164-014-0403-7
Aggressive behaviors in adult rats deprived of playfighting experience as juveniles. Potegal M., Einon D. Dev Psychobiol. 1989 Mar;22(2):159-72.https://www.ncbi.nlm.nih.gov/pubmed/2925003
Oh, for the Joy of a Tickled Rat http://www.nytimes.com/2016/11/11/science/tickling-rats-neuroscience.html?rref=collection/sectioncollection/science&action=click&contentCollection=science®ion=rank&module=package&version=highlights&contentPlacement=4&pgtype=sectionfront&_r=0Nov. 10, 2016. The New York Times.