When you think of play, the actual nature of playing, you don’t associate it with playmates who can weigh upwards of 70kg sporting sharp claws and a mouthful of large canines. Yet this is what playing includes when you are part of a wolf pack. With such a high risk of injury, it is no wonder that scientists have longed to understand exactly why wolves play. Recently, research out of the University of Veterinary Science, Vienna, has investigated that very question by recording the playful interactions of both puppy and adult grey wolves (Genus species).
Despite play being widespread throughout the animal kingdom, the true function of the behaviour is relatively unknown. The most accepted theory regarding animal play is that it is crucial for both the strengthening of social bonds and the establishment/maintenance of dominance relationships between group members. A past investigation of gelada baboons and tonkean macaques found that two individuals who engage in more playful interactions are more affiliative towards each other outside of the play context. Similarly, in spotted hyenas the frequency of playing was correlated to a decreased amount of displayed aggression, whilst an investigation on yellow-bellied marmots supported the dominance assessment hypothesis: that individuals within a hierarchy will use play to examine the physical abilities of opponents, allowing them to gain a competitive advantage without risking serious injury.
One such animal that lives in a hierarchical social group is the wolf. As packs are characterized by cooperation, high social cohesion and dominance relationships, they are in many ways the ideal species in which to study play — as the latest research demonstrates.
The wolves used in the latest study originated from North America but were born and raised at the Wolf Science Centre, Austria. A total of 26 hours of video footage was captured on a puppy wolf pack in 2009 and on a mixed-age group in 2012 who had a previously established hierarchy. This allowed researchers to analyse the benefits of playing in a puppy pack and then how play changed as juvenile wolves became part of an adult pack.
Two key questions were investigated: Do pairs that play more have fewer aggressive interactions outside the play context? Does more relaxed play leads to more affiliative behaviour? In addition to this, the scientists also wanted to find out if competitive playing was correlated with the rank of an individual within the pack’s hierarchy.
Researchers found the more time that each pair of wolves engaged in play, the fewer aggressive interactions were observed within the pack. Similarly, the more relaxed play that a wolf experienced the more affiliative their relationship was with others. It was also found that those individuals who were ranked closely in the group’s hierarchy tended to engage more in competitive play. These results allowed the researchers to begin to define and discuss the possible functions of play for both puppy and adult wolf packs.
One of the benefits of playing with different pack members is to reduce the amount of aggressive interactions experienced: this not only maintains group cohesion but also reduces the potential of serious injury. This is further supported by the argument that play strengthens the social bonds between wolves as the longer a wolf spent in relaxed play, the friendlier its behaviour was.
This research also supported the dominance assessment hypothesis. Observed only in the puppy pack, aggressive play was positively correlated with aggressive interactions outside of play, with those pairs with less clear dominance ranks spending more time in competitive play. Therefore, scientists have suggested that play in wolf puppies may help to define their hierarchical rank and establishes close social bonds between pack members. This is important for more effective future cooperative interactions regarding hunting, territory defence and pup rearing.
Overall, this investigation found more significant results than previous studies due to the sample including wolves of various age groups and observing play between siblings. This demonstrates the importance of researching play regarding ontogeny, i.e. the development of behaviour as an animal matures. In terms of the function of play, the differences between relaxed and competitive play clearly has an important role within the wolf pack. Whilst it can help strengthen the social bonds between individual wolves, it can also be applied to determine where a wolf sits in terms of the group’s hierarchy. This behavioural variety demonstrates the importance of scientific study on the play behaviour of various animals, with fascinating results being found regarding the true function of play.
Cafazzo et al. “In wolves, play behaviour reflects the partners’ affiliative and dominance relationship.” Animal Behaviour: Volume 141, July 2018, Pages 137-150
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