A SUDDEN cold snap could bring a late influx of wintering birds to a Severnside reserve, experts say.

Slimbridge Wetland Centre, near Berkeley, has seen fewer than usual migrating swans, geese and ducks arrive this winter.

The mild weather has also led to large flocks of waders choosing to stay in the UK in larger numbers than in recent colder winters.

But a change in the weather could lead to a delayed migration and a cold snap predicted over the weekend is likely to encourage them to complete the last leg of their migration.

Slimbridge reserve manager Dave Paynter said: "This warmer, wetter winter has been really interesting for birdwatching, contrasting with the past two winters, which have been cold and dry.

"This upcoming cold weather will act as a prompt for birds to move further south and the wind direction will create perfect flying conditions."

Mr Paynter said higher numbers of waders, such as lapwing, dunlin and golden plover, had stayed in the UK so far. But fewer of the 300 or so Bewick's swans which fly in to spend the winter at Slimbridge each year had so far arrived.