Sorry about the thread-drift, but since it was mentioned.

Bass, I think you'll find it's only swans on the Thames that belong to the Queen.

Swans on the upper Thames can be owned by the Queen, The Guild of Dyers, and the Guild of Vintners. Swan-Upping takes place once a year to mark cygnets belonging to the guilds with notches on the bill - all unmarked swans on the river are the property of the queen. The ownership of cygnets depends on the ownership of the parents. If these are owned by different parties, the cygnets are shared out half and half, according to a set of rules. If one parent is owned by the queen, her swan-keeper chooses which ones and also has any odd ones left. The Guilds have alternate days on which they have similiar preference over each other.

A publican friend of mine used to be part of the vintner's boat crew, so I used to accompany them up the river on my boat. We had some wonderful song sessions in the pubs at lunchtime and evenings.