Sterna dougallii – Môr-wennol Wridog – Scarce passage migrant; former breeder.
The Roseate Tern breeds in colonies dotted along the shores of the Atlantic, Indian and Pacific Oceans, stretching from Europe in the north to Australia in the south. The European population migrates to winter off the coast of West Africa.
E. Lort-Phillips visited Grassholm in 1883 to inspect the nesting place of a small colony of Roseate Terns which then frequented the island. Lockley et al (1949) referred to recorded breeding at Grassholm in c.1885. Mathew (1894) stated that the Roseate Tern formerly nested on Skokholm stack. No other breeding records have been traced.
There were three further recorded occurrences in the 19th century, one at Caldey in April 1875, one obtained at Pembroke in May 1887 and housed in the collection of a Dr Mills and one picked up dead near Pembroke in 1885. First recorded in the 20th century on the 10th September 1958 when three were seen off St Ann’s Head. Thereafter an average of four birds per annum were recorded in 32 years between 1963 and 2008, with nine in 2004, 11 in 1989 and 17 in 1990.These were presumed to be mostly coming or going to Ireland where the bulk of the European population nests.
The majority of Roseate Terns have been noted between the 1st July and the 28th September.
Distribution of total birds 1963-2008, July – September in six day periods.
The graph was compiled from records of two at Amroth on the 14th August 1973, two at Penally on the 16th August 1973, two at Ramsey on the 19th September 1973, one in the Cleddau Estuary at Llangwm on the 13th September 1976, one in the Nevern Estuary on the 17th July 1980, one at Cwm yr Eglwys on the 5th July 1990, a total of 17 at Skokholm and a total of 77 at Strumble Head. Most have involved sightings of one or two birds per occasion but there were four at Skokholm on the 31st July 1990 and again on the 24th August 1992, one to five per occasion were involved in the Strumble Head series but eight on the 9th July 1988 and again on the 25th August 2004, with 11 on the 29th July 1990.
Additionally one was noted at Strumble Head on the 2nd October 2000 and one at Cwm yr Eglwys in mid October 1971.
All records involved adult birds save for two juveniles at Skokholm on the 31st July and the 5th August 1990.
Very few were recorded in spring. They were: one at Caldey in April 1975, two at Poppit on the 20th April 1998, one at Fishguard Harbour on the 24th April 2007, one at Skomer on the 23rd May 1995 and one at Strumble Head on the 27th May 1985.
June records were: two at the Gann on the 30th 1995, one at Strumble Head on the 12th 1998 with two there on the 19th in 1983 and the 23rd in 1984.