Crows win bird-brain battle

CROWS are the intellectual champions of the bird world, the first avian “IQ test” has found.

A novel index that rates birds’ intellectual capacities using observations of their behaviour in the wild has been developed by scientists at McGill University in Montreal. Birds from the crow family, which includes ravens and jays, top the list, followed by hawks, woodpeckers and herons, according to the research by Louis Lefebvre. At the bottom of the league are partridges, new world quails, emus and ostriches, while parrots score surprisingly badly despite their particularly large brains.

Professor Lefebvre’s “avian IQ index” draws on more than 2,000 reports of unusual and imaginative tactics to find food.

The index reflects the number of different kinds of original behaviour reported by birdwatchers for each species. More than 100 reports — about 5 per cent — involve members of the crow family. Crows on the Pacific island of New Caledonia fashion tools from leaves and twigs to fish for insects hidden inside trees or earthworks, in a similar fashion to chimpanzees. Experiments with scrub jays have shown that they learn to store foods such as peanuts that last a long time, ahead of more palatable but more perishable food such as crickets.

The reports also include evidence of particularly shrewd vultures in Zimbabwe. During the country’s civil war in the 1970s, vultures would sit patiently at the edge of minefields, waiting for gazelles to be blown up.