fly from their breeding ground in the Arctic tundra to Britain to rest and feed over winter, before they head back ahead of spring.
The pressure on Whooper and particularly Bewick's swans
is mounting all the time.
However, experts at Gloucestershire wildfowl sanctuary were stunned to discover that a pair of Bewick's swans
returned to winter at the Wildfowl and Wetlands Trust centre at Slimbridge - with new partners.
Mr Madge said it was possible that mute swans could have been in contact with whooper and Bewick's swans
during their winter stay in the UK as well as other migrating birds.
And further west, near Berkeley Castle, is Slimbridge Wildfowl and Wetlands Trust, home to thousands of birds, including flamingos and Bewick's Swans
which journey 2,600 miles from Russia every year.
Winter really wouldn't be winter without the hundreds of majestic Bewick's Swans
that fly in from arctic Russia to spend the festive season in the relative warmth of Gloucestershire.
About 500 migratory Bewick's swans
at a park in Yonago, Tottori Prefecture, were apparently terrified by millennium fireworks on New Year's Day and flew off, park officials said Monday.
FLOCKS of Whooper and Bewick's Swans
have been arriving to spend the winter roosting on deep, open water alongside our resident Mute Swans.
Toshitaka Koseki, head of Yonago park, said, "Even the small number of Bewick's swans
remaining in the park on Saturday evening left.
Spotted Redshanks and Twite remain at the nearby nature reserve, with Bewick's Swans
near Shotwick boating lake, Flintshire.
THREATENED Bewick's swans
are arriving in the UK from their Russian breeding grounds with larger numbers of youngsters than experts have seen for more than a decade.
There will also be an update on the migrating Bewick's swans
that return to Slimbridge every year, and Welsh wildlife expert Iolo Williams takes to the seas in search of the fin whale.
UNTIL FEBRUARY 24 See up to 9,000 whooper and bewick's swans
at the Welney Wetland Centre near Wisbech, Cambridgeshire.
The Two Swans Bitter label features Bewick's swans
in flight and resembles a painting by the artist and naturalist Sir Peter Scott who founded the first WWT conservation site at Slim-bridge, Gloucestershire in 1946.
A large flock of Whooper and Bewick's Swans
remains by Shotwick Lake, while downriver more than 100 Twite are still at Connah's Quay nature reserve.