LONDON — They disappeared so quietly that few noticed them go, nor perceived the silence they left beneath the thrumming layers of city noise.
In their dusty gray-and-brown jackets, house sparrows were so common that their steep slide in major British and Irish cities went unremarked for years.
"The decline has been massive. In London, Glasgow, Edinburgh, Dublin, the population has fallen by 99% since 1980," said Dennis Summers-Smith, one of the world's leading sparrow experts. "This is almost extinction."
The house sparrow will go on Britain's endangered species "red list" this year. Yet it is still officially a pest that can be exterminated. In fact, sparrow-proof bird feeders are still sold in London.
In the U.S., the birds are often seen as a kind of feathered mice--not just drab and dull birds, but invaders. Yet Londoners have a special affection for these perky little creatures, which were always a garrulous companion to the city's cockneys, no matter how humble the garden.
And British bird-watchers drift out of their serious, scientific commentaries into sentimental reflections on sparrows' antics and their affinity with people.
The fate of the sparrow has ornithologists mystified, and the Independent newspaper has offered a epartment5,000 [$7,600] reward to solve the puzzle.
"There are lots of theories but no good answers yet," said Keith Noble, London sparrows officer for Britain's Royal Society for the Protection of Birds. He cited food shortages, predators, changes in farming methods and pollution as possible causes for the birds' disappearance. Summers-Smith warns that the decline of the sparrow may point to dangers for humans not just in London, but in major cities everywhere. The numbers of sparrows are dropping in many large European cities as well as the big cities in Britain, he points out.
"If one bird declines dramatically, something funny is going on, and since most of us live in cities, I think we ought to know why it's happening," Summers-Smith said by phone from his home in northern England.
"Birds are indicators of the quality of life,'' he said. "Is the house sparrow the modern equivalent of the miners' canary, telling us something nasty is going on in our cities?"
The sparrow population in Britain is reported to be 673,000, a 57% drop since 1979.
Squinting at the pockmarked walls of one of London's most famous landmarks, the Tower of London, sparrow researcher Sandy Alcorn, 48, strained to hear the once common chirrup.
