The great black-backed gull is one of the handsomest birds of the gull family, but owing to its destructive propensities amongst small birds, rabbits, and occasionally young lambs, a continual warfare has been waged against it for years by farmers and gamekeepers, until now it is almost entirely banished to the outlying parts of the country. Before the lighthouse was erected on Sule Skerry, large numbers of this species frequented the island; but the lightkeepers found them such arrant thieves that they reduced their numbers considerably. There are still about twenty pairs resident on the island all the year round, and they seem to find plenty of food either on land or at sea. Their breeding-time is in May, and sometimes as late as June. When the young are hatched the parents are continually on the lookout for food, and I have often seen them swoop down and seize young rabbits. Frequently they make desperate efforts to capture the old rabbits, but never successfully. They lay three eggs in a nest composed of withered grass, and the process of incubation lasts about four weeks. [Illustration: _Herring gull._] A small colony of herring gulls stays on the island all the year round, but in summer vast flocks of them are in evidence when the herrings are on the coast. Only the residents remain to breed, and about a dozen pairs annually rear their young and spend their whole time in the vicinity. Some of the young must emigrate to a more genial climate, for although rarely disturbed their numbers are not increasing. They lay three eggs early in May, and sit about four weeks. When hatched, the young immediately leave the nest, and are so like the surrounding rocks in colour that when they lie close it is almost impossible to discover them. When hunting for food for their offspring, these gulls are almost as great a pest as their cousins, the great black-backed, and are more audacious thieves.