Calidris canutus – PIBYDD YR ABER – Winter visitor and passage migrant. Not recorded in June
Mathew (1894) considered Knots to be autumn and winter visitors, appearing at the end of August and beginning of September. He quoted Goodwick Sands and Pembroke as localities for them. Lockley et al. (1949) agreed that they were autumn and winter visitors, usually in small parties of under 20, but occasionally in larger flocks, for example 100 at Dale on 6 November 1938.
The Knot is now erratic in its occurrence in Pembrokeshire. Small numbers, usually 20 or less, may winter on the Cleddau Estuary in some years, and sometimes larger groups of 50-100 appear, but seldom stay for long. A count of 500 was made on the Pembroke River on 22 January 1972. Small influxes have also been noted during cold spells.
They are more widespread, but not numerous, during passage times, when they can occur on any of the estuaries, beaches, and offshore islands, and sometimes in coastal fields. Very few pass through in the spring between March and May; usually single birds can be seen, but occasionally groups of up to six birds occur. Knots are more frequently seen in the autumn, when there is a small but marked passage off Strumble Head, with flocks of up to 85 passing between August and October. These are evidently birds that do not stop off in Pembrokeshire, for no comparable numbers are seen elsewhere at that time. Knots were attracted to the lighthouse at Strumble Head on 25 September 1985 during nocturnal passage.