Breeding swans on the River Thames are facing the double threat of dog attacks and the invasive American mink, the Queen’s Swan Marker has said.
David Barber said the number of cygnets on the river were down on last year as he and his team began the annual week-long survey of their numbers, an ancient ceremony known as Swan Upping.
It dates back to the 12th century when the ownership of all unmarked mute swans in Britain was claimed by the Crown in order to ensure a ready supply for feasts.
Today, the Queen’s Swan Marker has the duty of counting the number of young cygnets each year on certain stretches of the River Thames and its surrounding tributaries, and to ensure that the swan population is maintained.
Mr Barber said: “So far it’s only the first day and it’s less cygnets then last year.
“We’ve had a pretty rough time with nesting swans and dog attacks, all sorts of things – like mink.
“They’re not indigenous to this country and they’re breeding like mad on the river here, and they do take a lot of young cygnets.
“And with all the other birds of prey and as I mentioned dogs – we’ve been trying to encourage people to keep their dogs on a lead in the nesting season – it’s been very difficult for them.”
American mink are thought to have escaped into the wild from mink farms decades ago and have had an enormous impact on Britain’s wildlife, with the decline in the numbers of water voles partly attributed to them.
Swan Upping is normally held on the third Monday of July and begins with teams in rowing boats, known as Thames Skiffs, taking to the water to access the number of young swans.
It also serves as an annual health check with swans and cygnets weighed and checked for signs of disease or injury.