This gannet colony chooses an odd spot

IRELAND has a new gannet colony; the first to be established since 1988.

The birds have chosen a little promontory jutting like a large toe from the cliffs on the north side of Lambay, off the Dublin coast. The site is unusual in that it’s not a stack. Nor is it isolated from the rest of the island. Lambay seems an odd choice in another way; it’s inhabited.

Several hundred gannets took to resting on the promontory last year. This summer, eggs were laid; Steven Newton of BirdWatch Ireland recorded 57 nests on 27 June.

I visited the colony a month later and did some counts. There were 24 chicks on August 1, with a few birds still on eggs. Babies under parents are difficult to see, but I don’t think I missed many.

Getting a new colony up and running is difficult for gannets. At Great Saltee off the Wexford coast, for example, they took decades to get going. One or two pairs nested there in 1929 and every year after that, but by 1954 there were still only four nests. The following year, the number rose to 17 and the colony took off. In 1987, there were more than 700 pairs nesting on Saltee. This, Ireland’s third largest gannetry, was probably colonised from Grassholm, a low-lying island off the Pembrokeshire coast, which can be seen from the Rosslare to Pembroke ferry. Grassholm has the second-largest gannetry in the world, with about 30,000 nests each year. Lambay brings to six the number of colonies in Ireland, while Britain has 17, mostly in Scotland. For the species as a whole, there are 43, all in the North Atlantic.

Seabirds have come under increasing pressure in recent decades; terns have fared particularly badly and some species are in serious trouble. Gannets, true Celtic Tiger birds, appear to be thriving. Back in 1966, J B Nelson estimated the annual rate of population growth at 2% to 3%.

Gannets were persecuted by fishermen and their eggs and young harvested; in 1851, William Thompson, writing about Little Skellig, mentioned that people in Valencia used to “pay to kill young gannets for food”. The bird’s low-point occurred around 1880. There were only two colonies and the main one, on Little Skellig, had only 30 nests. Then numbers began to rise. In 1882, Skellig had between 150 and 200 nests. By 1908, there were almost as many as there are today; 20,000. This jagged rock has always been the flagship Irish colony. In 2004, Alyn Walsh of the Wildlife Service took a series of high-resolution photographs from an aircraft. These enabled Sarah Wanless and Stuart Murray to come up with an accurate total of nests; 29,683.

Gannets began visiting the Bull Rock, 4km off Dursey Head, in 1853 and bred there in 1858. With more than 1,500 nests, the Bull colony is really an extension of the one at Skellig. The two are within sight of each other and a mere 20km apart.

The tiny Clare Island colony dates from 1978. It’s on a jagged stack overlooked by cliffs, a remote and spectacular location; spending a week on Clare last year, it took me three days to find it.

The choice for Ireland’s next colony couldn’t be more different. Ireland’s Eye, off Howth, is a mere 14km from the centre of Dublin and seems an unlikely location for a colony. These birds like their privacy. They won’t nest close to human habitation although they don’t appear frightened of people.

During summer weekends, there is a constant stream of visitors to the adjoining cliffs. The Celtic Tiger has spawned a huge number of boats, many of which come right up to the stack for close-up views of the nests. The birds, however, seem to take this in their stride and the colony has prospered. Founded in 1989 when 17 well-grown chicks were recorded, the number had reached 188 by the year 2000. The new Lambay colony, a mere 10km away, is an offshoot.

That the gannet population continues to expand is remarkable, considering the pressure on the marine environment in recent decades. These members of the pelican family live mainly on shoal fish, such as herring mackerel and sand-eels, which they catch by plunge-diving from the air. Herring and mackerel are heavily exploited by the fishing industry and gannets, you might expect, should be feeling the pinch. Although they occasionally take fish from nets, they are less likely to become entangled in the meshes than are guillemots and razorbills. Nor are they as vulnerable to contamination from oil spillages as these species. The key to success for a seabird is to live long enough to produce viable offspring. Gannets don’t breed, on average, until they are about seven years old and lay only one egg each year from then on; it takes a long time for a gannet to produce an heir. We don’t really know how long gannets live; the metal rings we put on their legs, have a shorter life than the birds themselves. However, a gannet ringed in July 1961 at the Bass Rock, was at North Ronaldsay in December 1998, 37 years later.

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