STAINES, England (Reuters) - Dressed in a traditional scarlet coat and with a feather in his hat, Queen Swan Marker David Barber led six wooden rowing skiffs up the River Thames on Monday as bird counters began the old English tradition of Swan Upping.
The five-day census goes back to the 12th century when the Crown claimed ownership of all mute swans and the birds were often destined for the royal dining table.
Today, it is a way of collecting data and assessing young cygnets for injury or disease.
"Swan Upping is the way of monitoring the welfare of the Thames swans," Barber, who lead the so-called Swan Uppers, told Reuters.
"It dates right back to the 12th century when swans then were eaten, they were an important food; but of course today it is all about conservation and education."
From their boats, each flying flags and pennants, the teams round up the swans on the Thames, shouting "All Up!" when a brood of cygnets is spotted.
They bring the birds ashore -- sometimes flapping -- where adult swans are counted and cygnets are weighed, measured and examined before being released.
After the five-day journey that takes the Swan Uppers from Sunbury near London to Abingdon near Oxford, the Queen's Swan Marker will write a report. Last year, markers ringed 120 cygnets.
Reporting By Georgina Cooper and Will Russell; Editing by Angus MacSwan