Today’s article comes again from sciencedirect, and it’s the last literature review I’ll do for a while. It discusses play as an indicator for good welfare in captive and production animals. The challenges associated with understanding the motivations of play, and a brief history of landmark studies concerning play behaviors.
Temple Grandin writes that play in dogs may be training for different social situations. She supports this because dominant animals will change roles to a subordinate position and vice versa. In this way dogs and others would be ready to handle new situations outside of their norm. One benefit of play the article mentions supports this theory, that it’s sheer variability and fluidity may prepare animals for the unexpected. While the rest of their survival and social behaviors are predictable and procedural, play constantly creates new challenges and situations to react to that aren’t life or death. I think this makes sense, but I also think it’s even broader than Grandin puts it. Playful bucking and jumping by cattle, goats, sheep, and horses doesn’t seem to be play behavior related to dominance or social skills. To address this, the article lists several schools of thought as to the main purpose of play.
The first category believes in long-term benefits resulting from play. This includes benefits such as somatic development (differentiating muscle fibers, motor skills, etc.), proficiency in species specific behaviors (hunting, sex behaviors, etc.), and general improved physical and emotional flexibility across novel situations (social changes, new environments, anything new). There’s a lot of research supporting this school, but it doesn’t completely answer the question. Adult animals still play, even those that have sexual experience or have no need to hunt. This thinking largely explains why we see so much more expression of playing behaviors in juvenile animals, and is well supported. This sometimes doesn’t pan out well welfare wise, as experience with sexual or aggressive behaviors may not benefit say, your neutered indoor cat.
The second category is more recent, and proposes that play provides primarily immediate benefits to the animal. The first idea is that play provides/communicates information about the immediate environment it finds itself in. This may be information concerning other group members, its effectiveness physically in that situation, or its current level of development. Another idea is that play is self medicating; as it’s been proven that play releases natural opioids (Pellis & Pellis, 2009). Finally, play may be used for social communication. An animal can reinforce its status, reduce tension, or “break the ice” with a strange animal. I like this theory, but just like the other one, it doesn’t provide a complete picture. It sounds like a cop-out, but I think the reality is a mixture of the two thoughts. Behavior is rarely black and white, and I’m convinced by the research on both sides of the debate. What will be interesting is when we single out species specific behaviors and determine if they reflect the immediate benefits as opposed to the long term benefits. Dogs aren’t a good model because the pedomorphism nature of their evolution makes them predisposed to juvenile play their entire lives.
The bulk of the article relates all of the information to the use of play as an indicator of good welfare. It’s not a new idea, and the article provided a very comprehensive pros and cons list. The pros being that play is contagious, it releases opioids, it doesn’t occur in depressed or ill animals, and animals appear to enjoy it. The cons being that it’s extremely variable between species and individuals, and that occasionally it can increase in frequency to respond to stress (lending evidence in support of the second theory). Eventually, play is identified as a decent indicator of good welfare, and promoter of animal contentment. I agree with the conclusion, and also with the final statement that we have many questions left to ask.
Suzanne D.E. Held, & Marek Spinka (2011). Animal Play and Animal Welfare Animal Behaviour (81), 891-899