Strong Competition Does Not Always Predict Play Asymmetry: The Case of South American Sea Lions (Otaria flavescens)

Abstract

Although play fighting has been studied for over a century in both human and non‐human animals, quantitative data on marine mammals are still scarce. Here, we investigated play fighting in South American sea lions (Otaria flavescens), one of the most sexually dimorphic species with an extreme polygynous mating system, high levels of both intra‐ and inter‐sexual competition. All these features make South American sea lions a good model species to test some predictions on play fighting. Our results indicate play is restricted to juveniles, being inhibited among adults, and as to be expected in a species that shows a high degree of sexual dimorphism, it is mainly expressed in males. Even though playful interactions were punctuated by competitive behaviours, animals played in a highly symmetric way and were able to adjust their competitive playful interactions in a flexible manner and so reduce the risk of escalation to a minimum level. They were highly selective in their choice of playmates by limiting the number of players per session and playing more with age‐matched companions and friends. All these factors taken together are probably at the basis of the low risk of escalation recorded during the study. This result is predictive of a high ability and motivation of these animals to engage in play behaviour which can have a possible role not only in the acquisition of dominance status, but also in establishing and maintaining social relationships, an unexpected role in a so highly competitive species.

Differences in play can illuminate differences in affiliation: A comparative study on chimpanzees and gorillas

“…To quantify the level of play asymmetry ( Play Asymmetry Index , PAI), we classified the patterns in offensive and defensive behaviors [ 22 , 27 , 73 , 80 ] (see Table 2 for the definition of the play behavioral items). We calculated the PAI for each session as follows: the number of “wins” for animal A in a dyad equaled the number of offensive behaviors (see Table 2 ) by A directed at B plus the number of defensive behaviors (see Table 2 ) by B directed toward A. B’s “wins” were calculated in the same way.…”

“…The involvement of adults in playful interactions is sensitive to the degree of tolerance and social cohesion of a given species [ 10 , 30 , 33 , 68 – 72 ]. Adult play is usually inhibited in species that are characterized by both strong adult competition and low levels of social affiliation (e.g., [ 24 , 30 , 73 ]). If adult play (as grooming [ 66 ]) is a form of social investment [ 12 ], especially used in some species that rely on reciprocal social support to cope with competitive relationships, we expect that adult chimpanzees play more than adult lowland gorillas (Prediction 1).…”

“…During social play, especially play fighting, animals can balance their offensive and defensive manoeuvres to give the possibility to the playmate to counterattack [ 25 , 77 ]. This playful tactic prolongs the session thus making play more successful [ 21 , 73 , 78 ]. In many species of mammals, individuals that are more dominant and physically powerful generally limit their strength in order to balance the session while playing with subordinates or physically weaker subjects (self-handicapping behaviour; e.g.…”

“…In many species of mammals, individuals that are more dominant and physically powerful generally limit their strength in order to balance the session while playing with subordinates or physically weaker subjects (self-handicapping behaviour; e.g. squirrel monkeys, Saimiri sciureus , [ 79 ]; rats, Rattus norvegicus , [ 12 ]; South American sea lions, Otaria flavescens , [ 73 ]). During play fighting, some behavioral patterns can be categorized as 'offensive' (e.g., pushes, tackles, bites, and chases), whereas some others can be defined as 'defensive' (e.g., shelter, wriggle, flee).…”

Social play changes reflect differences in biology and development of three felids

“…The absence of sexual differences in play was previously shown for domestic cat (Caro, 1981) and now we can confirm the same pattern in other felids: in lynx, with almost no sexual dimorphism, and in leopard cat, that is sexually dimorphic in adulthood but not when young (Heptner & Sludskii, 1972;Nowell & Jackson, 1996). Generally, sex differences are expected in the species with a high degree of sexual dimorphism (Poirier & Smith, 1974;Llamazares-Martín et al, 2017), which young felids do not have (Nowell & Jackson, 1996). In our study the enclosures size varied.…”