By Morgan Engmann ’20
Across species, there has been confusing and conflicting data on how juvenile play habits predict behavior outside of play and dominance rankings in an animal society. For some animals, pairs of playmates let each other win in about a 50:50 ratio while in others the more dominant individual nearly always wins. In a recent study by Cafazzo et al. , (2018), researchers looked into the interesting dynamics that occur in puppy play in wolves (Canis lupus), a species known for their cooperative pack nature and dominance ruled society. The study created “puppy packs” that contained several pairs of siblings raised in captivity and observed their behaviors for several months by recording duration and type of play interactions as well as interactions outside of play. They then observed behavior of the puppies when introduced to a group of adults, which they called mixed age groups. They hypothesized that different types of play have different social roles in packs, and that these roles may change with the age of the wolves.
In packs containing only puppies, the amount of time spent in competitive play was positively correlated with how many aggressive interactions the puppy had outside of play. It seems that aggression translates into both play and everyday life for puppies when surrounded by other puppies, likely because of the unstable dominance relationships in the group. The young wolves are likely trying to find their place in their society by constantly trying to be better than their neighbor. Without clear social dominance, it seems that play cannot be used as a tool to increase the affiliative bonds between wolves. Interestingly, siblings were less aggressive to one another than they were to strangers even though they likely close in social ranking.
In mixed age groups, wolves that had more play time in general, be that competitive or relaxed, had less aggressive interactions outside of play. This is different than what was seen in the puppy only groups, and perhaps this reveals a change due to dominance becoming more important. As dominance is established, wolves have less issues with one another, therefore allowing for more play which could act as an agent to increase bonding in the pack. Also in mixed groups, it was seen that the more time a wolf spent in relaxed play, the more affiliative interactions it had with others outside of play. With clear dominance established, wolves will spend less time competing and more time relaxing. However, when dominance is not so clear in adults, as it usually is with wolf siblings, more competitive play occurred. This was another trend not seen in puppy only groups. It seems that because dominance relationships are so important in adult wolves, play can be used as a positive tool for pack bonding only when their social hierarchy is stable and well established.
There were several trends that were seen in both the puppy only groups and mixed age groups. The frequency of competitive play was positively correlated with rank indicators that are seen outside of play. This means that wolves that displayed more dominant behaviors outside of play tended to engage in competitive play more than subordinate wolves. Also, during these play interactions, the more dominant wolf always won. Pairs of wolves that were similar in their social rank interactions spent more time in competitive play than pairs with with a more established dominance pattern, showing that play time in wolves is important to creating and maintaining their social hierarchy system. This study also found that there was no correlation between sex and time spent in competitive or relaxed play, which is likely due to the fact that in wolf societies, males and females have similar roles.
Overall, this study shows that puppies behave differently depending on the social group they are interacting with, and that play has different roles depending on the social situation in the pack. Puppy groups have a less stable social hierarchy established, likely leading to the increase in
competitive and aggressive actions both in and outside of play as the young wolves try to find their place. In a stable pack with clear dominance relationships, play is used more like it is in humans: to produce friendships, increase cooperation, and probably to have a little fun too!
Cafazzo S., Marshall-Pescini S., Essler J., Viranyi Z., Kotrschal K., Range F. 2018. In wolves, play behavior reflects the partners’ affiliative and dominance relationship. Animal Behaviour, 141, 137-150.
