King Charles’ annual swan census begins on the River Thames

Swan uppers hold mute swans during the ancient tradition of Swan Upping, the annual census of the mute swan population on the River Thames in London, Monday, July 14, 2025.(AP Photo/Thomas Krych)

LONDON — Scarlet uniforms flashed against the riverbank. Wooden skiffs glided in formation. A young swan, gently lifted from the water, was measured, inspected and released.

The annual five-day census of swans belonging to King Charles III – known as Swan Upping -- began Monday on the River Thames to assess their health.

One of the British monarch’s less-known titles is Seigneur of the Swans — Lord of the Swans — and according to ancient lore, he or she owns all members of the mute swan species found in Britain’s open waters.

Every year, a team of carefully selected oarsmen, known as Swan Uppers, are tasked with finding the swans on a stretch of the Thames.

When a family is spotted, they shout, “All up!” and the boats quickly surround the birds, marking them and checking for signs of disease or injury.

“It gives us an indication of what’s going on throughout the country,” said David Barber, who wears a scarlet jacket and a white swan feather in his cap and bears the title of King’s Swan Marker. “It’s a tradition, but I think it’s serving a very useful purpose as well.”

Barber has been leading the event for more than 30 years. He is accompanied by a vet and oarsmen dressed in three colours: red for the king, white for the Worshipful Company of Vintners and blue stripes for the Worshipful Company of Dyers. The last two are medieval London trade guilds that were granted ownership of some Thames swans in the 15th century.

The census tradition dates to the 12th century, when swans were considered an important food for royal banquets and feasts.

While swans are now legally protected from hunting, they face threats from disease, pollution, vandalism and cruelty, Barber said.

Their numbers have declined over the last two years, primarily due to outbreaks of avian flu across Britain, he said, adding that only 86 young swans were found during last year’s Swan Upping, which was 45% fewer than the year before that.

But Barber appeared positive at the end of the event’s first day, with a total of 16 young swans recorded.

The census continues until Friday, traveling from Sunbury, on the outskirts of London, to Abingdon, 80 miles (130 kilometres) upstream.

Lydia Doye, The Associated Press