Play behaviour, not tool using, relates to brain mass in a sample of birds

Abstract

Play behaviour and tool using in birds, two well-delineated and amply researched behaviours, have generally been associated with cognitive abilities. In this study, these behaviours were related to relative brain mass in a sample of Australian native birds. Despite suggestive research results so far between cognition and tool using, this study found no significant difference in relative brain mass or in lifespan between tool-using birds and non-tool users. By contrast, in play behaviour, subdivided into social players and non-social players, the results showed statistically very clear differences in relative brain mass between social, non-social and non-players. Social play was associated with both the largest brain mass to body mass ratios and with the longest lifespans. The results show that play behaviour is a crucial variable associated with brain enlargement, not tool using. Since many of the tool using species tested so far also play, this study suggests that false conclusions can be drawn about the connection between tool using and cognitive ability when the silent variable (play behaviour) is not taken into account.

Brain Size Associated with Foot Preferences in Australian Parrots

“…In a range of species, the left hemisphere has been shown to be responsible for topdown control (such as routine behaviour) and the right hemisphere for environmentally elicited behaviour such as response to threats and social partners [68]. Social play behaviour in parrots and other clades is correlated positively with brain size [69] but, for this behaviour, there has been no study of differences between the hemispheres. By contrast, social recognition is known to be largely right-hemisphere controlled [70,71] and, as Yamazaki at al.…”

Birdsong and the Neural Regulation of Positive Emotion

“…There are many examples of birds engaging in behaviors that appear playful or pleasurable ( Burghardt, 2005 ; Emery and Clayton, 2015 ; Pessoa et al, 2019 ). For example, there are reports of raptors dropping and catching objects, crows sledding, swans surfing, and parrots producing an emotionally contagious play call that is comparable to human laughter ( Hewitt, 2013 ; Emery and Clayton, 2015 ; Schwing et al, 2017 ; Kaplan, 2020 ). Vocal behavior is considered a direct reflection of an individual’s emotional state ( Cheng, 2003 ; Burgdorf et al, 2008 ; Panksepp, 2010 ; Briefer and Le Comber, 2012 ), which suggests that contrary to common perceptions, birds, and in particular songbirds, are among the most emotionally expressive species in the animal kingdom.…”

The Evolution of Playfulness, Play and Play-Like Phenomena in Relation to Sexual Selection

“…The psychological tendency toward play exhibits many criteria of evolved adaptation. It is present in all human cultures (Huizinga, 1938(Huizinga, /1980Gosso and Otta, 2003;Sandseter and Kennair, 2011) and is typical of mammals (Špinka et al, 2001;Burghardt, 2005), especially regarding large-brained mammal orders (Iwaniuk et al, 2001), suggesting play is at least as antique as the first mammals (Late Triassic), but it might have independently evolved in birds with delayed reproduction (Diamond and Bond, 2003;Kaplan, 2020), fish, turtles and octopuses (Kuba et al, 2003;Burghardt, 2005). Playful phenomena are culturally valued (Sutton-Smith, 2001).…”