England's swans population counted in annual 'swan-upping' The Queen, along with one other family and two liveries, owns the birds.

GORING-ON-THAMES, England -- Among the most quirky of Britain’s historic traditions, the practice of counting swans, or "swan-upping," has a long history dating back hundreds of years.

The tradition is named after the officials who carry out the duties, swan uppers. The monarch claims ownership of all mute swans -- the species often represented in fairy tales and art -- in the U.K., as part of a tradition of royal entitlements thought to date back to 1186.

Swans, mostly their young cygnets, were considered a delicacy and served at banquets and feasts.

Each year, stocks of wild swans were rounded up and counted to ensure numbers and a healthy population. This usually took place in late July when the cygnets are typically born, but are not yet able to fly.

The tradition involves swan uppers catching swans with their bare hands, as they row down the various rivers in England where the birds most frequently gather.

The uppers wear formal dress and travel in traditional wooden boats known as skiffs. Uppers who count for the Crown fly the Queen’s flag.

The birds are caught, then weighed and checked for diseases. The data is stored for conservation efforts.

Swans in the U.K. are owned either by the Crown, by the Ilchester family or by two livery companies who have rights to own swans.

Uppers representing each will carry the appropriate flags on their skiffs and, alongside the royal Uppers, will sail 79 miles of the Thames over a week to count the swan population.