Puffinus griseus – ADERYN –DRYCIN DU – Regular autumn passage migrant. Has not been recorded in February, June or November.
This bird was not mentioned by Mathew (1894), but Lockley et al. (1949) regarded it as fairly regular during the early part of September, and Saunders (1976) assessed it as annual in its occurrence off the coast in extremely small numbers. The records for the 1950s to 1970s are predominantly from the Skokholm area and average three birds per autumn, with a maximum of six in 1970 and 1971.
Regular and frequent observation from Strumble Head during the 1980s has shown that far more than this pass southwards each autumn, an average of 81 per year being seen between 1983 and 1987. This figure excludes sharp daily peaks in passage occurring after southwest gales, when Sooty Shearwaters were presumably diverted downwind into Cardigan Bay but beat back out to sea in procession when the wind veered to north of west. Greater numbers pass Strumble Head in such circumstances, 237 on 1 September 1985 and 397 on 3 September 1983 being the largest counts. The passage period extends between 3 July and 30 October, but single birds have been seen off the Smalls on 22 March 1984 and off Strumble Head on 2 January 1988, 3 May 1982 and 23 December 1983, suggesting a few remain to winter in the northern hemisphere.
SAUNDERS, D.R. 1976. A brief guide to the birds of Pembrokeshire. Five Arches Press.