Cambridgeshire residents are being urged to fill up their feeders and get involved in the world’s largest wildlife survey this weekend.

It is the RSPB Big Garden Birdwatch, now in its 38th year, which takes place on 28, 29 and 30 January.

The public are being asked to spend an hour watching and recording the birds in their garden or local public space, then send their results to the national charity.

An RSPB spokesman said: “The Big Garden Birdwatch provides valuable information about the wildlife using our gardens in winter, enabling us to monitor trends and declines. It is also a chance to take time to enjoy the nature on our doorsteps.”

The top three birds seen in gardens in Cambridgeshire during last year’s watch were house sparrow, starling and blackbird.

Daniel Hayhow, RSPB conservation scientist, said: “With results from so many gardens, we are able to create a ‘snapshot’ of the birds visiting at this time of year across the UK.

“Even if you see nothing during your Big Garden Birdwatch hour, that’s important information too, so please let us know.”

“This year, if the cold snap persists, we could see some more unusual birds appearing in UK gardens.

“Look out for Scandinavian visitors such as redwings, fieldfares and waxwings in search of berries.

“While redwings and fieldfares come to the UK every winter, waxwings come in large numbers only in some years when food supplies are scarce at home.”