Movements of ringed Mute Swans Cygnus olor across the Irish Sea

The majority of British Mute Swans Cygnus olor do not migrate large distances. Of 119 Mute Swans ringed on the Isle of Man, 23 (19%) were subsequently sighted away from the island, ten of which subsequently returned to the island. Approximately half of these were cygnets when ringed and most were first recorded away from the island within their first two years of life. In contrast, only c0.1% of Mute Swans ringed on the mainland of north-west England were recorded crossing the Irish Sea. The results suggest that movements across the Irish Sea from the Isle of Man are regular in both directions, with many birds returning.