Dozens of swans have been found dead in the Grand Union Canal in London along with geese and other wild birds, prompting an investigation by the government’s Animal and Plant Health Agency (Apha).
Environment groups say they are “concerned” by the unusual cluster of deaths, the cause of which has not yet been confirmed.
Wendy Hermon, operations director at rescue organisation Swan Support, said the charity has collected more than 25 swans since the end of September, from locations including Paddington Arm, Alperton, Greenford, Hayes, Southall, and Northolt.
“We’ve collected over 25 swans but [the number found dead has] been a lot more than that, and we’ve just had a report of more this morning so it’s still ongoing,” she told The Standard on Wednesday.
“They’re just everywhere. It’s all round the London area.”
She said the charity has also collected around 15 dead geese, as well as moorhens, coots and ducks, and has had a report of a dead heron.
“This time of year especially with the cold weather, it is normal sometimes for the weaker ones to die anyway,” said Ms Hermon, who has worked for Swan Support for around 30 years.
“But we’re picking up really healthy, heavy, good-condition birds, that wouldn’t otherwise die. It’s not common just to walk along the canal and to just see two or three swans in a small area just floating dead.”
Tests carried out on the birds have reportedly come back negative for avian flu, but Ms Hermon says Apha has not yet ruled out the virus.
Apha carries out year-round surveillance of dead wild birds, and tests them to monitor outbreaks of avian flu.
Ms Hermon said it is “frustrating” that no cause of death has yet been confirmed, as it means Swan Support is unable to treat birds they find unwell for fear they have bird flu.
“I’m concerned obviously,” she said. “We can’t bring [unwell birds] back to our rescue centre and give them fluids or anything like that, until we know what it is. It’s quite frustrating for us, because we’re seeing swans poorly.”
The Grand Union Canal is the longest canal in the UK and connects London and the Midlands. Beginning in the capital, one arm of the waterway runs to Leicester while another, stretches for 137 miles to Birmingham.
The Canal and River Trust, which looks after the waterway and others across the UK, said it too is “concerned” by the reports of dead swans.
As the trust’s specialists have not found other dead animals or fish where the dead birds have been found - as they would expect to if it was a pollution incident - it believes an avian disease is the most likely explanation.
An Apha spokesperson said: “We are aware of a number of wild birds deaths in the Uxbridge area in West London and are investigating these deaths as part of our wild bird surveillance programme.
“We are working closely with local organisations to understand the extent and cause of this incident.”
Amid a major bird flu outbreak two years ago, in October 2022, a number of swans and geese were found dead in the Grand Union and Regents canals in central London. They were thought to have died as a result of the virus.
A Canal and River Trust spokesperson added: “Members of the public should not touch or pick up any dead or visibly sick birds they find, but instead immediately call the Defra helpline on 03459 33 55 77, giving as accurate a location as possible.
“We would also encourage people to report any suspected wildlife crime to the police.”
