THIS weekend you could make a huge contribution to wildlife by taking part in the Big Garden Birdwatch.

The Royal Society for the Protection of Birds (RSPB) are organising a national survey of birdlife and are hoping the results will help them find out who is top of the pecking order in UK gardens.

"The aim is for people to take part in this survey and send their results to us," says Fiona Hazleton, south Essex community project manager for the RSPB who is based at Wat Tyler in Pitsea.

"By having as many results as possible, it gives us an idea of what birds are doing well and what birds aren't."

The survey takes place this Saturday and Sunday and half a million people across the UK are being encouraged to spend an hour spying on their bird neighbours to help make the 2008 survey another record-breaking event.

In 2007, more than 400,000 people spotted six million birds across 236,000 gardens, helping reveal the winners and losers in the garden bird world.

Big Garden Birdwatch aims to find out which birds are the most common visitors to UK gardens in winter. It also keeps an eye on how others are faring and produces a snapshot of winter bird populations.

"For example, last year we found out that the house sparrow had declined in numbers considerably," says Fiona. "Without the survey, we would never have known that."

The house sparrow claimed the top position for the most birds seen in gardens in 2007 but the species has shown a rapid decrease since 1979, dropping from ten birds per garden to 4.4.

Sarah Kelly, Big Garden Birdwatch co-ordinator, said: "The survey is fun, easy and only takes an hour to complete. It's a great way for people to contribute to a significant piece of wildlife research without even having to leave the comfort of their homes."

"You really don't need to be an expert to take part. Whether you're young or old, an expert' or a beginner, there really is no better place to start than the RSPB's Big Garden Birdwatch."

Participants in Big Garden Birdwatch have made a significant contribution to monitoring garden bird numbers over the past three decades. The results highlight some garden birds are in need of help.

The starling, beaten to the top spot in 2007 by the house sparrow, has seen its numbers plummet from 15 per garden to an average of 3.7, a decline of 76 per cent.

However, the chaffinch and great tit have both seen their numbers increase since 1979 by 36 and 52 per cent respectively.

To take part, simply spend one hour sometime this weekend counting the birds in your garden or local park, and record the highest number of each bird species seen at any one time.

The morning is the best time to look, when the birds are out and about feeding after a cold winter night.

"Peoples' gardens are the best place for birds," says Fiona. "So it's really important that people lend us a hand this weekend. It gives us more peices in the jigsaw."

For further information and online resources to help you with your birdwatch, visit the RSPB website www.rspb.org.uk/birdwatch an online survey form will be available from this weekend until 18 February 2008.