BIRDWATCHERS in Hampshire will be out in their numbers this weekend as the county prepares for the largest Big Garden Bird-watch ever.

The event is run by the Royal Society for the Protection of Birds (RSPB), and Hampshire last year had the highest number of participants in the country with 15,000 people responding.

This year, for the first time, the survey will be able to isolate the Southampton results.

Besides being a lot of fun, the Big Garden Birdwatch also has a serious side and hopes to find out why populations of sparrows and starlings are decreasing in the county.

RSPB spokesman Adrian Thomas said: "This is a great way for everyone to learn about the birds in their own back gardens and help us find out how well those birds are doing both locally and nationally.

"In the past, Big Garden Birdwatch has highlighted declines in birds like house sparrows, song thrushes and starlings and enabled us to begin more detailed research to discover what the problems are."

He added: "We're really keen to get as many people as possible to take part in Hampshire. It's easy to join in and the more results we get, the more useful the information will be."

In Hampshire as a whole, house sparrows, starlings and blue tits have been consistently in the top three birds most commonly spotted.

Blue tit numbers have stayed stable since the early 1990s.

But the number of house sparrows and starlings has fallen dramatically and in 2004, for the first time ever, starlings slipped into fourth place behind blackbirds.

To take part in the Big Garden Birdwatch all you have to do is spend an hour in the garden this weekend watching the birds.

Then tell the RSPB the largest number of species you see at any one time, along with the total number you see during the hour.

More instructions are available at the RSPB website, www.rspb .org.uk/birdwatch - or you can call 01273 775333.