More than a third of Bewick swans – many of which will soon be flocking to Fenland’s Ouse Washes for the winter – have disappeared since 1995, when numbers peaked at 29,000.
New figures show that by 2010 the population had plummeted to just 18,000, as a result of a range of factors like illegal hunting, power lines, lead poisoning from buckshot and wind farms, according to the Wildfowl and Wetlands Trust (WWT).
WWT scientists now fear that the next census, due this winter, will reveal a further, more worrying decline.
The charity is currently raising money through its new Hope for Swans appeal in order to deliver the Bewick’s Swan International Action Plan, which aims to stabilise the population.
Eileen Rees, the trust’s head of UK waterbird conservation, said: “At this time each year the Bewick’s swan flocks start to return to the UK’s wetlands from their arctic breeding grounds. But recently they have been returning with too few young, and the numbers indicate that they aren’t producing enough offspring to replace all the swans that have died over the year.
“We have two possible solutions: to find out and address what’s hampering breeding, and to reduce the number of preventable deaths along their migration route. We have a plan in place to do both, and much work is under way already, but we need to do it all if we’re to change the fortune of our wildest and most beautiful swan.”
The Bewick’s swan was named in 1830 after Thomas Bewick, an engraver who specialised in illustrations of birds and animals. Less than half of its population breeds each year, and each pair that does produces just one or two young, so the population struggles to replenish itself.
The Ouse Washes are expected to receive between 25 and 33 per cent of the whole of the Northwest European Bewick’s Swan population this winter, making the site a hugely important wetland habitat for the species.
For more information on Bewick’s Swans, including where to see them in the UK, visit www.wwt.org.uk/swans