Great Black-backed Gull
Status: Resident along all Irish coasts. Less frequently seen inland, usually only following storms.
Conservation Concern: Amber-listed due to a decline in the breeding population. The European population is regarded as Secure.
Identification: A large gull and the largest widespread gull to be seen in Ireland. In adult plumage has blackish upperwings showing a broad white margin and darker wing tips showing white 'mirrors ' (white at the very tips surrounded by black); the rest of the plumage is white. Has a bulky body, broad wings, dull pink legs, a very heavy bill and a thick neck. Has four age groups, like Herring Gull and Lesser Black-backed Gull, and attains adult plumage after three years when it moults into adult winter plumage. Juvenile, first year birds and second winter birds lack blackish adult like feathers on the upperparts, having instead strongly patterned upperparts which are barred or chequered. Birds at this age can be difficult to tell apart from other large immature gulls. The black develops in older immature birds, usually in the spring of its third year, initially in the mantle and back. Younger immature birds have a narrow tail-band which fades as the bird moves towards maturity.
Similar Species: Herring and Lesser Black-backed Gulls.
Call: Very deep and gruff and similar to other large gulls, such as Herring Gull.
Diet: Fish, waste from commercial fishing, offal, and other birds, for example auks at colonies in the breeding season. Will also rob other birds of food - kleptoparasitism.
Breeding: Breeds on the ground in colonies all around the coast of Ireland. Most colonies are on well-vegetated off-shore islands, or in other areas difficult of access, making the species to census. A few birds breed inland where they associate with freshwater lakes in Co. Mayo and Co. Galway.
Wintering: Resident birds are joined by immigrants in the winter. Found around the coast with some birds inland.
Where to See: Not difficult to see around the coast of Ireland. Larger colonies occur on islands, such as Lambay, County Dublin (nearly 200 nests) and Inishmurray, Co. Sligo (nearly 120 nests).
Monitored by: Wintering birds are monitored through the Irish Wetland Bird Survey. Breeding seabirds are monitored through surveys carried out every 15-20 years, the last was Seabird 2000, which was undertaken between 1998 & 2002.