DO you love the BBC’s Winterwatch and Springwatch programmes? And have you ever fancied yourself as a bit of a naturalist?

Well, now is your chance to take part in what is said to be the world’s biggest wildlife survey.

And you can do it without ever leaving your garden...

This weekend (in fact, for three days from Saturday to Monday) almost half a million people across the country are expected to take part in the RSPB’s annual Big Garden Birdwatch.

You don’t need to spend all three days monitoring the wild birds which come to your garden - or even one day.

All that is needed is for you to make a note of the birds which visit your garden (or your local park, if you’d prefer) in one particular hour over the course of the three days, then send your count to the RSPB.

The results of all those observations will then be gathered together to give an unrivalled picture of just what is happening to Britain’s wild birds.

This will be the 39th Big Garden Birdwatch.

And surveys in previous years have enabled us to understand the ways in which bird populations are changing, says Chris Collett, the RSPB spokesman for the north of England.

Some of our common wild bird species are doing very well - birds like the blue tit, blackbird, chaffinch, goldfinch and wood pigeon.

Others, however, have seen their numbers collapse since the first Big garden Birdwatch in 1979.

The number of starlings has dropped by almost 80 per cent since the first Garden Birdwatch in 1979, Chris says - while greenfinch numbers have fallen by almost 60 per cent.

We still don’t fully understand why - although scientists at the University of York found evidence that Prozac and other antidepressants which make their way into the water supply could be affecting starlings.

The drugs are taken up by earthworms which live in sewage. The worms are then eaten by starlings - and the drugs build up in the birds’ blood, affecting their appetite and their libido, the researchers found.

Whatever the reasons, the first step in being able to do something about falling wild bird numbers is establishing that there is a problem, says Chris.

By establishing which birds are increasing and which are decreasing in numbers, the Big Garden Birdwatch helps us do exactly that. “It is extremely valuable information,” Chris says.

So how do you take part?

Set aside one hour this coming weekend to keep a watch out in your garden or local park.

Make a note only of birds which land in your garden or in the park, Chris says. Don’t count individual birds - the same bird might come, fly away, then return, so you could end up counting the same bird over and over again.

Instead, make a note of the maximum number of each type of bird which lands in your garden during your hour of observing, then send your observations to the RSPB.

You can get a free Big Garden Birdwatch pack which will enable you to do this from the RSPB at

If you’re not confident in your ability to recognise different species of birds, the RSPB website has a handy bird identifier which should help you.

And if you’re really not sure what a bird is, you can always take a photo and tweet it to the RSPB at @natures_voice, where someone will be able to identify it.

“You never know, it may be something that’s very rare, in which case we want to know,” say Chris.

For those in York, there will be a special event in the Museum Gardens this Saturday and Sunday, where RSPB staff will be on hand to give advice on how to take part.

There will be tick-sheets available for anyone who wants to go off and birdwatch by themselves, and garden guides to give tips on where to find different species.

The sightings will be recorded on a board at ‘basecamp’ - but the event will also be great training for anyone who wants to do a birdwatch in their own garden.

For more information visit yorkmuseums