## Facts

- The Crown treated mute swans as “royal fowl,” claiming prerogative rights over unmarked wild swans at liberty in open and common rivers.
- The Exchequer issued a writ to the Sheriff of Dorset to seize approximately 400–500 wild unmarked (“loose”) swans for the Queen’s use.
- Dame Joan Young and Thomas Saunger, private landholders, resisted the seizure and claimed an exclusive right to all wild unmarked swans nesting, breeding, and frequenting a defined creek or estuary adjoining their Dorset estate.
- The defendants asserted their right by alleged immemorial usage (prescription) by local abbots before the Dissolution of the Monasteries and by later conveyances tracing through a Crown grant of the former monastic estate to a predecessor in title.
- The dispute was heard in the Exchequer of Pleas to determine whether the claimed private right could defeat the Crown’s prerogative seizure.

## Issues

1. Whether a subject may acquire by prescription a right to “all wild unmarked swans” (ferae naturae) breeding and frequenting within a particular creek.
2. Whether rights connected to royal swans can be transferred through private conveyances to confer general property in wild unmarked swans, beyond any limited royal privilege.
3. Whether unmarked swans at liberty on open and common rivers remain subject to seizure by the Crown notwithstanding adjacent private ownership claims.

## Decision

- The court ruled for the Crown and upheld the Exchequer writ directing seizure of the unmarked wild swans.
- A prescription claiming “all wild unmarked swans” within a particular creek was held invalid.
- The court treated wild swans as ferae naturae, for which any private property claim is qualified and cannot support the sweeping prescriptive right asserted.
- Unmarked swans that have gained natural liberty and swim in open and common rivers may be seized to the monarch’s use by prerogative.

## Legal Principles

- A private prescription to have “all wild swans” that are unmarked and ferae naturae within a defined area is not legally good.
- Unmarked swans at liberty in open and common rivers are subject to Crown prerogative seizure.
- Property interests in wild animals are limited and arise only upon lawful possession; such interests do not support an absolute, area-wide claim to all wild animals of a kind.
- Because swans are “royal fowl,” a subject’s interest in swans, if any, exists only by royal privilege (ratione privilegii) and cannot be expanded into general ownership by prescription or broad private transfer.

## Conclusion

The court rejected an asserted exclusive prescriptive and derivative title to all wild unmarked swans in a creek and confirmed that unmarked swans at liberty in common rivers fall within the Crown’s prerogative and may be seized for the sovereign’s use.


Case of Swans, 77 Eng. Rep. 435, 7 Co. Rep. 15b (Exch. 1592)