Play behaviour and cognition in Australian native birds (#239)
This paper investigates play behaviour in Australian magpies and Australian land birds generally. First it had to be established how many Australian species are known to play, a second question considered play incidents in different species and a third concerned the relationship of play to cognition. It was hypothesised that play behaviour is of vital importance for long life and survival generally. There can be little doubt that its presence or absence amounts to developmental differences (neural and behavioural) that may have had a key role in avian evolution. Social play has been of particular interest because it is regarded as requiring high cognitive abilities. Comparative data on Australian avian species (tool use, innovation, cooperative breeding and play behaviour in conjunction with lifespan and brain size) were collated from all available publications in Australian ornithological journals between 1900 and 2014, forming the basis for an overview of cognitive data now emerging in Australian avian species. The results are important and in part novel. My own studies of magpie behaviour have shown multiple manifestations of ‘social’ play not all on the same level of difficulty and conceptualisation, i.e., cognitive complexity may not be involved in all play tasks. Although brain to body weight ratios did not yield significant associations, species that play were found to have significantly longer life spans than non-players, and to have greater brain mass. This was characteristic of both parrots and other species calculated separately. Brain mass was also larger in non-parrot species that use tools and tool using was associated with lifespan. There was only a weak link between cooperative breeding and play behaviour but a strong link between long-term bonding, long lifespan and play behaviour. While play is unevenly distributed among Australian orders, and even varies within families, it seems to confer substantial advantages.