July 29, 2009—Once upon a time in England, swan was a delicacy, prompting expeditions to "brand" wild, unclaimed fowl as royal property. The queen's swan marker continues the tradition today, but the aim is protection not consumption.

© 2009 National Geographic (AP)

Unedited Transcript

It's July and the swans and their young cygnets seem to know what's coming. These men, known as Swan Uppers, spend five days cruising this waterway, constantly searching out the highly prized birds that flock here. They are led by Her Majesty the Queen's Swan Marker who is responsible for carrying out an inventory of all the unmarked, mute swans on the Thames between London and Oxfordshire. The Swan Uppers still wear their traditional uniforms and fly royal flags on their boats. Historically, this was a way to inventory swans in a manner that was similar to cow branding. Swans were a valuable medieval food and were served at banquets and feasts. However, the birds are no longer eaten. The Queen has the right to ownership of all unmarked mute swans in the UK swimming in open water. But today she only exercises her ownership on certain portions of the Thames and its surrounding tributaries. SOUNDBITE: (English) David Barber, The Queen's Swan Marker: "We are actually taking the young cygnets from the river and we are checking them over to make sure their health is maintained in the future." Once the crew successfully captures the swan it is taken on shore to be weighed, checked for injuries, given an ID number and released. SOUNDBITE: (English) David Barber, The Queen's Swan Marker: "It is quite a simple method. You are using six traditional rowing skiffs. You will actually go round the family of swans and the young cygnets. As you work the boats in closer and closer in a circle then you can lift the swans out by hand. Of course the swans do flap, you know they have large wings up to three metres and of course they weigh up to nearly fifteen kilos (33 lb ). So they're a very heavy bird." Often, the swans are injured due to a number of causes including encounters with fishing gear and dog attacks. In the 1980s, the number of swans on this stretch of water began declining due to lead poisoning by fishing weights. At the end of the swan census the Swan Marker releases a report identifying the number of broods and cygnets counted on the Thames. Swan Upping may seem like a quaint way to spend an afternoon, but this is a serious activity. This data will help the Swan Marker's office organize appropriate conservation methods.