Where is the cockney sparrow?

Residents were asked to count sparrows

More than 9,000 Londoners have taken part in a wildlife survey researching the decline of the city's sparrow population.

Experts are trying to establish why numbers of the much loved "cockney sparrow" have fallen dramatically over the last 30 years.

The bird was once a common sight in London's parks and gardens.

But now the survey has shown there are very few sparrows in inner London where they once used to be abundant.

If something is wrong with the sparrow, it is vital that we find out what's behind it

Ken Livingstone, Mayor of London

Research is under way by a number of organisations such, as the Royal Society for the Protection of Birds, to find possible reasons for the decline.

However, the London Biodiversity Partnership (LBP) called on the city's residents to help identify where the sparrows are.

Residents counted almost 75,000 sparrows - but most were seen in outer areas rather than in the City and Westminster.

House sparrows were seen at 73% of participating homes - ranging from 94% in Havering to 17% in Westminster.

Expert theories

The survey also found that the birds were more likely to nest in homes built before 1945 than in newer homes.

London mayor Ken Livingstone, who heads the LBP's House Sparrow Species Action Plan, said: "The sparrow is part of London's identity and their friendliness has helped make wildlife accessible to all Londoners.

"Their decline should worry us all - the sparrow's world is our world. If something is wrong with the sparrow, it is vital that we find out what's behind it."

More than 2,600 sparrows were counted in Kensington Gardens in 1925 but numbers dropped to 885 in 1948, 544 in 1975, 81 in 1995 and only eight in October 2000.

Theories on the cause have ranged from a lack of nesting sites to competition for food from other birds, but so far no-one has been able to say for sure.

Londoners took part in the survey between 18 June and 12 July 2002.