A unique wildlife project in which researchers recognise individual swans by their faces has reached its 50th anniversary today.
The Wildfowl and Wetlands Trust’s (WWT) Bewick’s swan study is one of the longest-running animal research projects in the world, examining how the smallest of the northern migratory swan species is faring, the charity said.
Bewick’s swans breed in the Russian Arctic and three populations head south each winter to central and eastern Asia and to north west Europe, where the population rose to a peak in the mid-’90s but has declined by a third in recent years.
The research has identified long-term threats to Bewick’s swans including habitat loss and climate change and has helped establish an internationally-binding “species action plan” to maintain numbers and statutory protection for sites in Russia and the UK, WWT said.
Researchers at WWT have also recorded the individual lives of Bewick’s swans, such as Casino who lived for 27 years and produced 34 cygnets, and Derek – named after a much-valued volunteer – who disappeared for five years before mysteriously reappearing.
And they have witnessed personal dramas, such as that of Sarindi and Saruni, a pair who got “divorced” but now co-exist at WWT’s reserve at Slimbridge, Gloucestershire, with their new partners.
New work this year will see transmitters attached to a small number of swans to track their exact route and flying height during their migration north, to inform plans for offshore wind farms, the WWT said.
The scheme, in which researchers tell individual birds apart by their features rather than by ringing them with identification tags, has spawned sister studies in five other countries since it was started by conservationist Sir Peter Scott.
They have produced data on the impact of factors such as weather, climate and disturbance on the swans’ breeding and survival rates, their choice of wintering sites and their behaviour.
The original study began on February 11, 1964, when Sir Peter was painting swans outside his window in Slimbridge and noticed each had a unique pattern on its bill.
His young daughter Dafila helped paint and name dozens of swans, and later formalised the work into a scientific research project.
Each new WWT researcher has to spend a winter learning the swans’ faces before taking over the scheme, with more than 9,000 individual swans now identified, the charity said.
Ms Scott said: “My father would have been very proud to see the scientific research still going strong, 50 years after we first started painting individual swans and giving them names.
“The study is everything my father set up WWT to be. Visitors and researchers watch the swans together, experiencing the magic of being close to them and following their loves, power struggles and tragedies from one generation to the next.
“Through this understanding, we’ve produced decades of high quality research which has led to statutory protections for important wetlands and hope for the species’ future.”