It is an offence to intentionally injure, take or kill a wild swan in the UK.

(As native wild birds, swans enjoy statutory protection under the Wildlife and Countryside Act 1981 It is an offence to take or possess the egg of a wild mute swan, or to damage or destroy the nest of a mute swan whilst in use or being built. 
I am writing this because one of my visitors asked me if the Queen really ate swan, and yes it seems there is an internet myth that all swans belong to the Queen, this is not true, however it is true that certain swans in certain areas are her majesty’s property.  Every July a head-count of all the mute swans on the Thames is taken, this is called the Swan Upping ceremony.  They are then marked for ownership either by the Crown or by the Vintners’ and Dyers’ Livery Companies, which were granted their rights of ownership by the Crown in the fifteenth century.)