Irish Name: Saidhbhéar
Scientific name: Rissa tridactyla
Bird Family: White-headed Gulls
Conservation status


Summer visitor to steep coastal cliffs along all Irish coasts. Disperses to the open ocean in winter and less frequently seen.


A small gull, slightly larger than Black-headed Gull, which is basically grey above and white below. Adults are easily told apart from other gull species by the solid black wing tips, showing no 'mirrors' (white at the wing tip), and two toned grey upperwing. Adult birds have a yellow bill and dark legs. Adults show white heads in the summer and a dark patch behind the eye in the winter. Juvenile and first year birds have a bold dark 'W-pattern' across the wing and a dark tail band, although these features can be much faded by the first summer/second winter. Second year birds are similar to adult birds but can show black fringes to outer primaries, black on the bill or winter head patterning in the summer months.


Noisy at colonies, giving a nasal call resembling its name. Can often be heard clearly over the sounds of other birds at seabird colonies.


Fish, waste from commercial fishing and invertebrates.


Forms colonies, sometimes thousands strong, often with other seabirds. Breeds on steep sea cliffs where it builds a nesting platform on the most vertical and sometimes improbably steep areas. Will occasionally use man-made structures such as old buildings, for example in Dunmore East, Co. Waterford.


Winters at sea.

Monitored by

Breeding seabirds are monitored through surveys carried out every 15-20 years, the last was Seabird 2000, which was undertaken between 1998 & 2002.

Blog posts about this bird


Rockabill 2019 - One week down, plenty to go!

Common Tern flying by the island at sunset, April 2019. (L.Gill)

We’ve finished our first week out here on Rockabill and it certainly did not disappoint. From Storm Hannah to the arrival of the Common Terns, it’s been an interesting week.

Waves breaking over the Bill during a bright spell in Storm Hannah (L.Gill)

Our bird species list is now at 21. Kittiwakes have started to occupy cliff ledges in KittiCity and KittiPoint along with in section 4C and out in the Bill.

Pair of Kittiwakes on a cliff ledge at 'KittiCity' on Rockabill Island. (L.Gill)

Black Guillemots have also started to spend more time on the island rather than rafting up around it. Every morning we go out to count them and our highest count so far has been 213!

Black Guillemots resting on the pier at Rockabill. (L.Gill)

Myself and Andrew have started to settle down into the routine of island life and getting stuck into our work. Emma, the third warden will be arriving tomorrow. All the study sites have now been cleared of tree mallow.

Removing the Tree Mallow vegetation from one of the Lighthouse gardens, to make space for nesting Terns. (L.Gill)
The same garden as above, after removal of all of the Tree Mallow vegetation - plenty of space for Common terns to nest on the ground now! (L.Gill)

We have taken out all the nest boxes from inside the house and sorted them in numerical order ready to go to their various parts of the island. Any nest boxes that were broken have been set aside to be repaired or replaced.

Sorting out some of the 900 nestboxes to be deployed around the island for nesting Roseate Terns! (L.Gill)

For birds that aren’t nesting in nest boxes, their nests will be marked with pegs. We took out all the pegs from last year and sorted them into Common Tern, Artic Tern and Roseate Tern piles. We then sorted all of the Common Tern pegs on bamboo sticks from number 1-250 and Roseate and Artic pegs will soon follow.

We use coded clothes pegs to mark nests on Rockabill - at the start of the season there are a couple of thousand to be sorted out! (L.Gill)

Last night we were treated to a beautiful sunset with Common Terns flying across making for some beautiful shots.

Common Tern silhouettes at sunset, from Rockabill Island. (L.Gill)

Common Tern silhouettes at sunset, from Rockabill Island. (L.Gill)
  • Lorna Gill & The Rockabill Team.

Similar Species

Black-headed Gull

Irish Name:
Scientific name:
Larus ridibundus
Bird Family:
Hooded Gulls