It may not have the dazzle of a royal wedding, but the annual "swan upping" is one of the oldest events in the British royal calendar.
Every English summer, men in red blazers and white trousers spend a week rowing up the River Thames, lifting the swans and counting them as locals and tourists look on.
"Each family of swans are taken out from the river," says David Barber, the Queen's swan marker. He leads the swan census every year. "They're weighed, they're measured and they're checked over."
Among her many ancient royal titles, the Queen of England is "Seigneur of the Swans" or Lord of the Swans. Since the 12th century, virtually all of England's native wild swans have been the property of the monarch. Whether because of that royal link or for their sheer beauty, they have long been among Britons' most cherished birds.
But all is not well among Her Majesty's swans.
In the 1980s, pollution and other pressures nearly killed them off. Since then, swan populations have recovered. But this year's swan upping returned some doleful news: Swans are increasingly the victims of human negligence — and even cruelty.
Many of the victims are brought to a swan sanctuary in Shepperton, on the banks of the Thames. Founder Dorothy Beeson has been helping swans for 35 years.
"That one's had a wing off," she says, indicating a nearby bird in the barn-like hospital, where dozens of swans convalesce in special straw-lined pens. "And the rest of them in here, I do believe are throat ops."
The commonest injury: throat lacerations, often caused by negligent fishermen. Beeson points out one swan that swallowed the baited hook of a fisherman too busy contemplating his beer can to watch his rod and reel.
"This one here had a 7-inch tear, which is like the inside of its throat being cut with a razor blade," Beeson says, pointing out an injured bird with a long line of stitches up its shaven neck.
Beeson has even seen swans who've had their eyes shot out with air rifles. But it gets worse.
"This is the carcass of the swan that we found, and as you can see, the carcass has been stripped," Ray Hallam, a member of the Friends of King's Mill Reservoir, says in the video. "You can actually see the cut marks on the feathers."
Locals say dozens of resident swans have vanished in the past couple of years, apparently bound for someone's dinner table.
This breaks one of Britain's most powerful taboos. Since Tudor times, only British monarchs and some venerable institutions granted royal assent have had the right to eat swans. For anyone else, killing a swan or eating a swan means a big fine or imprisonment.
"We are seeing a worrying increase in the number of these birds, which are being taken for food," says Grahame Madge of the Royal Society for the Protection of Birds.
Although these and other acts of cruelty form only a tiny minority of the British public's interactions with swans, he says, the trend is disturbing. "In the U.K., a lot of people love the birds," he says. "And many people cherish the sight of a swan as being something very special. But sadly, it seems that with their rise in number, we're actually seeing an increase in these incidents."
Back at the swan sanctuary in Shepperton, swans that are healthy enough to leave the hospital ward but too damaged to survive in the wild ever again are fed at a manmade lagoon.
A floating barrier cuts them off from the river — and from a world that brings new threats as old customs and beliefs die off.