Passage migrant and occasional winter visitor
This former common resident had by the late 1800s become only a rare visitor (Mathew 1894). Lockley et al. (1949) noted records from the Preseli Mountains and Dowrog. Since then, Marsh Harriers have been recorded in 25 of the 37 years from 1950 to 1987. Single birds wintered near St David's in 1954/55 and at Dowrog in 1982/83, all other records referring to passage birds, with singles occurring from 3 April to 14 June and from 3 August to 28 November. Most records are from coastal areas such as Freshwater East, Marloes Mere, Skokholm, Skomer, Ramsey, Trefeiddan, Llanwnda and Teifi Marshes, but they have been seen inland at Thornton, Jordanston and Loveston. One seen departing from Marloes Mere in May 1987 flew eastwards, steadily climbing, and at a great height was lost to telescope view.