Thanks to its simplicity and the small time it takes to do, the Big Garden Birdwatch has always had great support, providing us with a vital snapshot of the UK's birds each winter.
In 2007, over 400,000 people took part by counting the birds in their garden for an hour. Together they spotted 6 million birds across 236,000 gardens, helping reveal the winners and losers in the garden bird world.
Over the past three decades participants have made a significant contribution to monitoring garden bird numbers and helped highlight that some garden birds are in need of help.
The survey has recorded the huge declines in some of our most familiar birds. Since 1979, the number of house sparrows counted has fallen by 52% and the number of starlings by 76%.
However, it isn't all bad news - chaffinchs and great tits have both seen their numbers increase since 1979 by 36 and 52 per cent respectively.
To find out how you can take part, visit http://www.rspb.org.uk/birdwatch/index.asp or click the logo above.