A guy was jailed for some months in 1993 for shooting swans. Noone can eat them - all belong to the Queen, except interestingly in Orkney where Norse Udal law applies...."Under Udal Law, the ancient Norse system of inheritance and law, which the Viking settlers brought to Orkney, the swan is the property of the people, rather than the Crown.
The case was proven in 1910 by a Kirkwall lawyer who, accompanied by his friend, the Procurator-Fiscal, went out to Harray Loch and shot a swan. The case went to the High Court and the Crown lost.
Nowadays, Orcadians do not shoot swans, but the principles of the old Norse Udal Law still stand.
The swan is protected across the entire Great Britain by law under the Wildlife and Countryside Act." (quotation from Wild about Britain)