Australian magpies that live in flocks are more intelligent than their more solitary counterparts. We don't want to draw any conclusions from this about urban and rural humans, but the findings support ideas about how we got so smart in the first place.
Australian magpies are unrelated to European magpies but do have a similar color scheme. Recently named Australia's bird of the year in a hard-fought contest, the birds are members of the passerine order. They are actually one of the few native Australian birds to flourish since European colonization, coping well with urbanization, even if their relationship with cyclists can get nasty around nesting season. The Western Australian subspecies differs from its relatives over east, however, in that they live in groups of up to 17, rather than in pairs.
Dr Amanda Ridley of the University of Western Australia told IFLScience that magpies represented the perfect bird for testing a long-standing, but still controversial, theory; that living in groups makes animals more intelligent. Known as the “social intelligence hypothesis”, the idea runs that negotiating relationships requires a lot of brain power, and this spills over to other applications. Ridley said; “To test this you need animals with stable territories so you can find them, that spend a lot of time on the ground and that are habituated to humans.” Not only do the Australian magpies do all of these, but their complex songs have long hinted at their intelligence.
Ridley and colleagues gave four intelligence tests to magpies living around Perth in populations that ranged from three to 12 birds, publishing in Nature. "We showed that individuals living in larger groups in the wild show elevated cognitive performance, which in turn is linked to increased reproductive success,” co-author Dr Alex Thornton of the University of Exeter said in a statement. "Repeated testing of juveniles at different ages showed that the link between group size and intelligence emerged in early life." However, when the young birds were first tested group size had no effect, contradicting the theory that birds with genes for higher intelligence form larger flocks.
Ridley said the study also demonstrated the evolutionary benefits of intelligence, with smarter female magpies producing more offspring. She told IFLScience one of the future lines of research the team is interested in is establishing why this is the case. “Are intelligent females better at avoiding predators, do they get better food, or avoid conflict with others in the group?” she said. “Or are they better at seeking help from others in the flock?”