Altogether Now!

Living in groups makes you clever

- Peter Ryan

The demands of incubating eggs and feeding a brood of chicks results in most birds forming partnerships to breed. In most cases, these are simple male-female pairings, which explains why most birds are at least socially monogamous. By comparison, most mammals are polygynous, with one sex – usually the female – left to rear the offspring alone. But some birds take group living a step further, involving more than two birds in raising the offspring. Such species are termed cooperative breeders and the phenomenon is particularly common among birds breeding in southern Africa and Australia.

Living in groups brings its own challenges, including the need to develop and maintain social bonds. It has long been argued that social interactions are a key driver of the evolution of ‘intelligence’. Correlative studies suggest that social birds and mammals have better cognitive abilities and increased brain capacity compared to solitary species and experimental studies show that brain structure is related to group size in captive monkeys and even fish, but only recently has this been demonstrated in free-living animals.