Blue tits lose their bottle as milk thieves

Suburban Britain was fascinated when blue tits learnt how to peck open milk bottle tops on doorsteps and get at the cream underneath. But now, although the birds are as common as ever, their ability seems to have deserted them.

First observed about 75 years ago, the behaviour spread until, at its height in the Fifties and Sixties, there was barely a doorstep in the land that wasn't visited by the feathered raiders. Sometimes the birds followed milk floats and swooped when a delivery was made.

Dr Mark Avery, the director of conservation for the Royal Society for the Protection of Birds, said: "Our wildlife inquiry service has had one call about this in the past 10 years. It appears to have died out."

Professor Christopher Perrins, Emeritus Fellow of Ornithology at Oxford University, took a similar view. "It's my impression that it has ceased. I think it's gone," he said.

Ornithologists said that changes in people's milk-buying habits were probably responsible, although Professor Perrins said that because blue tits tended to be short-lived, it did not take much for bottle-opening to die out. "The tradition goes if it's not carried into the next generation," he said. The decline in doorstep deliveries, with more people buying milk from supermarkets, the change in containers, with more secure closures being fitted, and the switch from full-cream to semi-skimmed milk may all be behind the birds' loss of taste for our cream.

The milk industry also noticed the change. Jim Begg, the director general of the Dairy Industry Association, said: "There is a lot more protection of bottles now. But anyway, the birds don't go for bottles like they did. That's what everybody says."