The Skerries Islands are collectively of international importance because of their bird life.
Birds arrive and depart throughout the seasons from their Arctic breeding grounds and African wintering grounds. The Irish Government has designated these islands as Special Protection Areas (SPA) and Special Areas of Conservation (SAC) because of their importance for wildlife.
Rockabill (two islands) has the biggest breeding colony of Roseate Terns in North-western Europe. The birds stay on the island from April until September, when they return to their wintering grounds in Africa. Birdwatch Ireland provides special nest boxes and wardens to protect the birds and conduct research on their breeding and feeding habits.
St Patrick’s Island is one of the most important breeding sites in Ireland for Cormorants, with up to 1000 pairs breeding there in recent years. Cormorants and other seabirds can be seen hunting for Sprat, Sand Eel and Mackerel along the Fingal coast. Grey Seals breed on the islands during the winter months, with up to 80 individuals seen on the Island in early spring.
Colt Island, although the smallest of the islands plays an important part in the biodiversity of the group. It has an impressive range of bird species including Mallard, Shelduck, Eider Duck, and Ringed Plover all of which breed on the Island.
Shenick Island is the biggest of the four islands and the most important roosting site for birds in the area from autumn to spring. Every evening thousands of birds such as Brent Geese, Curlew, Oystercatcher, Ringed Plover and Turnstone gather on Shenick to roost and sleep, safe from predators.
Detailed documents: https://www.npws.ie/protected-sites/spa/004122
Skerries Islands: http://www.fingaldublin.ie/interior-pages/about-fingal/environment/islands/skerries-islands/
More info: http://www.fingalbiodiversity.ie/resources/interreg_living_coast/Skerries%20Islands%20Sign.pdf