species were observed. The island is a protected area, and seasonal visitor numbers are modest, leaving the birds little disturbed. Between 2016 and the previous major survey the population of three species of seabird had increased sharply, and others modestly, a couple were stable, and two had declined a little. As of the most recent multi-month study, in 2016, there are more than 4,000 guillemots and 1,000 razorbills, and hundreds of pairs of kittiwakes, cormorants and European herring gulls. Smaller numbers of fulmars, shag and great black-backed gull are also found, as well as some lesser black-backed gulls. There were observations of black guillemot and Manx shearwater, but these species have not been observed to breed on the island. Ireland's fifth gannet colony became established on the Stack around 1989, and there were subsequently more than 100 pairs breeding there each year. There are also up to a dozen breeding pairs of puffins, which used to be common; the Eye remains the best site to see these birds in Dublin. A limited number of peregrine falcons are found. In the 18th and early 19th century, goshawks were noted as building their nests here, but they are not listed in modern bird surveys covering Ireland's Eye. Among non-passerine species, a few shelduck and oystercatcher are routinely observed, as well as ringed plover. At least 17 passerine species have been counted, 8 definitely breeding on the island; examples include the hooded crow, rock pipit, stonechat, wren, blackbird and reed bunting. In 2016, for the first time, robins were observed to be breeding. Two breeds of goose overwinter on the island, greylag and pale-bellied Brent geese. Other visiting or winter-passage species include the short-eared owl and the sandwich tern. Other fauna Grey seals are abundant in the sea around the island, and haul out on rocks, as well as living in sea caves on the northern face and around the northeast. It is believed that a colony of 270 to around 350 seals exists on and between the Eye and Lambay Island. Harbour seals are also seen, though in much smaller numbers. Harbour porpoise are also present in the waters off the island in material numbers. There is also a population of brown rats, against which control measures are supposed to be carried out annually, and there are rabbits, burrowing primarily in dry grassland areas. A previous population of foxes, noted in the