Sparrows and starlings in decline

Sparrows and starlings are increasingly rare in gardens

Two of the UK's best-known birds - house sparrows and starlings - are in serious decline with millions of birds lost, according to government-commissioned research.

Cats, modern farming methods and new house designs are among the factors being blamed for the population falls.

Everyone loves the cockney sparrow

Humphrey Crick
Report co-author

The study by the British Trust for Ornithology (BTO) suggests more than 20 million birds have been lost in the last 25 years.

The population of house sparrows has dropped from 12 million pairs to seven million, a decline Environment Minister Michael Meacher said was very worrying.

The fall is worst in south-east England, Mr Meacher told BBC Radio 4's Today programme, while numbers have been rising in Scotland and Wales.

Falling food supplies

Starling numbers have dropped from 20 million to 8.5 million since the 1970s, says the survey.

"The major cause of decline in the case of starlings is the reduction of young starlings surviving the first year," he said.

That was probably a result of diminishing food supplies.

But numbers had fallen by two-thirds on farmland, said Mr Meacher.

"We have long suspected, and the research confirms, that the decline of starlings is closely related to changes in agricultural practice, such as the increased use of pesticides and the loss of pasture and unimproved grassland which has reduced food sources available to birds."

Causes of decline

Modern farming methods

Sealed roof cavities

Less loose grain

Growing cat numbers

The lack of hedgerows and unimproved pastures had hit birds in the countryside, while air pollution was causing problems in urban areas.

Mike Toms, from the BTO, said house sparrows in suburban areas had been hit by changes to house designs.

Birds could no longer get access to roof cavities to build their nests, Mr Toms told Today.

Feline threat?

The trust is now launching a house sparrow appeal.

Thursday's report says a study of a village in rural Bedfordshire suggested one of four pairs of sparrows in the village may have been hurt by cats.

"Cat predation is also likely to account for a large proportion of the juvenile mortality in the village," the report says.

An increase in the numbers of sparrowhawks, which were hit by pesticides in the 1970s, is another factor.

And in 2001, 16,000 house sparrows were killed legally by farmers.

Building on brownfield sites and cleaner streets are also identified in the report as other factors.

Wake-up call

In rural areas, farming methods and sealed grain barns are seen as the main factors.

Humphrey Crick, one of the report's authors, said he was not surprised the exact cause of the decline in towns had yet to be discovered.

"People have ignored towns as a habitat for so long," Dr Crick told the Independent.

"People are only just waking up to the fact that towns are an important place for wildlife as well as people.

"We should now be able to find the exact causes."

Dr Crick said sparrows were very popular - "everyone loves the cockney sparrow" - but their decline could point to other damage to the environment.

"It may be just the sparrow but it may not," he told BBC News. "It may be affecting a whole range of factors and possibly ultimately us."

The latest research follows concern about falls in numbers of garden song birds, such as song thrushes and blackbirds in recent years.