RSPB campaigners are calling for the public to take part in their garden bird survey - Nestwatch UK - during the society's Wake Up To Birds Week, which runs from May 25 to May 31.

For details ring 0870 601 0215 or write to Wake Up to Birds Week, RSPB, Somers House, Somers Road, Reigate, Surrey RH2 9DU.

The survey form will be available on the RSPB website at: www.rspb.org.uk/nestwatch

It said one in every four pairs of song thrushes nest in gardens, which are also a hugely important haven for other birds that are rapidly declining in numbers, such as the house sparrow, starling and spotted flycatcher.

Dr Andre Farrar, organiser of the RSPB Nestwatch UK project, said: "By telling us about their gardens and what birds are nesting in them, Nestwatch UK participants can greatly increase the understanding of what these birds need and how we can help to protect them in future."

The song thrush population during the period from 1988 to 1991 was thought to be 990,000 pairs in Britain. But between 1970 and 1998 the population fell by 59 per cent in the UK.

For more details ring 0870 601 0215 or write to Wake Up to Birds Week, RSPB, Somers House, Somers Road, Reigate, Surrey RH2 9DU.

The survey form will be available on the RSPB website at: www.rspb.org.uk/nestwatch