Rockabill

Rockabill comprises two tiny granite islets in the north Irish Sea 6.4 km east of the north Dublin town of Skerries. The land area is about 0.9 hectares but the majority is covered by the lighthouse and associated buildings.

Three BirdWatch Ireland wardens are based on the island for the breeding season spanning late April to mid August.

Rockabill is best known a tern colony supporting 80% of Northwest Europe’s Roseate Tern population, currently about 1,600 pairs. They nest with ca. 2,000 pairs of common Terns and smaller numbers of Arctic Terns. In addition, the low cliffs hold up to 200 pairs of black-legged kittiwakes and 60-80 pairs of black Guillemots. Virtually all seabird pulli are ringed every year and the majority of the breeding populations are thus of known age.

The foraging ranges of breeding kittiwakes have been assessed using GPS loggers and of Roseate Terns using boat-based visual tracking. Prior to becoming a SEATRACK site, GLS loggers have been deployed (and retrieved) on both Black Guillemots and Roseate Terns. In 2019 we deployed GLS loggers on the kittiwakes for the first time.