Experts at the Wildfowl and Wetlands Trust centre at Slimbridge, Gloucestershire, have witnessed a rare "divorce" between two Bewick's swans – with both parties bringing their new partners to the site.
It is only the second time in 40 years that such a separation has been recorded at the centre.
Julia Newth, its wildlife health research officer, said: "With swans, as long as they are both still alive, they will try to stay together. In this case, however, both swans and their new partners are now over-wintering on the lake at Slimbridge and things are a little awkward."
She said the original pair had not acknowledged each other with any signs of recognition.