Wolf pups more likely to play on equal terms with similarly aged partners

Wolf puppy play behaviors may be influenced by their play partner's age, according to a study published May 11, 2016 in the open-access journal PLOS ONE by Jennifer Essler from the Messerli Research Institute (Vetmed Vienna) and the Wolf Science Center, Austria, and colleagues.

Scientists have hypothesized that to facilitate social play, individuals may act to maintain equality by following a "50:50 rule," where each player is 'winning' or 'losing' 50% of the time. For instance, instead of using offensive tactics during play, a dominant animal may show 'self-handicapping' to put itself at a disadvantage, allowing a subordinate to 'win.'

The authors of the present study observed play styles in captive wolves, analyzing play interactions in puppy-puppy and puppy-adult pairs to test if the interactions adhered to the 50:50 rule. They found that play in wolf puppies did not appear to follow this rule. Puppy-puppy pairs consistently showed more equal play than puppy-adult pairs, although the degree of equality varied greatly. In puppy-adult pairs, however, the puppies engaged in self-handicapping and less offensive behaviors, rather than the adults.

The authors propose that such behavior may act to reinforce the dominant adult and subordinate puppy hierarchy established outside of play, and hope that continued research in this area may provide further insight.

Jennifer Essler notes: "The study presents the first evidence that wolf puppies do not show egalitarian play styles, and adult wolves do not appear to exhibit self-handicapping behaviors to engage the puppies in play. Thus, it does not appear that the retained levels of conspecific cooperation within wolves, compared to dogs, has selected for more egalitarian play styles."