This year the UK Wildfowl & Wetland Trust (WWT) and its partners in Iceland and Ireland are working together with new technology to gain insights into the migration patterns and problems faced by whooper swans.
The whooper swan tracking project has fitted seven swans with satellite transmitters in order to learn more about the bird’s behaviour as they travel from the summer breeding ground in northern Iceland to the winter waters of Caerlaverock on the Solway coast in Scotland.
Dr Kendrew Colhoun of the Irish Whooper Swan Study Group (IWSSG) said, “The purpose of the project is to find out exactly how the swans get to Britain and Ireland and what obstacles and difficulties they meet on their flight path.”
Because the whooper swans often migrate over 1,300 kilometres of sea in order to complete their seasonal migrations, their flight is considered one of the finest feats of bird aviation. The whooper is the largest of wild swans, weighing anywhere from 8 to 13 kilograms.
As the WWT’s reserve manager in Caerlaverock, Richard Hesketh, commented; “To carry such bulk for such a lengthy, uninterrupted flight over water is a magnificent achievement. Compare it with the smaller Bewick’s swan, which flies in from the Russian Arctic.” The Bewick swan migrates largely over land, giving it the option to touch down in bad weather. “The whooper doesn’t have that option.”
The journey is a dangerous one. One of the birds being tracked by satellite appears to have hit bad weather over the Atlantic. “I don’t think he (Merlin) is still with us,” says Hesketh sadly. “Despite getting very close to land, he didn’t quite make it. We had a pair a few years ago that took five days to make the sea crossing and still made it, but the birds don’t have a 100 per cent success rate, by any means.”
“Once they’ve made that first migration, the risks come down to power lines, wind turbines and lead poisoning or shooting,” he says. “Natural predators are few.”
Almost all of the 26,000 whooper swans which winter each year in Britain and Ireland come from Iceland.