Passage migrant, formerly bred. Not recorded from November to March
Sage (1956) concluded that the terns mentioned by Ray in 1662 as breeding at Caldey were “almost certainly Common Terns”. Mathew (1894) recorded a colony of about 20 pairs on Skokholm Stack which Lockley et al. (1949) believed had ceased to breed in 1916.
Mathew reported the Common Tern as “seen commonly on passage in spring and autumn” and Lockley et al. that it was “now by no means common on passage, when it is chiefly seen in September and October”. It has since proved to be sparse in spring, with up to 12 a day seen passing northwards off the west coast and islands between 12 April and 12 June. In the autumn it is more numerous, and has been recorded between 21 July and 28 October, principally off the north coast. The largest recorded count is of 182 passing Strumble Head on 26 August 1990.
SAGE, B.L. 1956. Notes on the birds of Caldey and St Margaret’s islands, Pembrokeshire. Nature in Wales 2: 333-340.