The Storm Petrel — Procellaria Pelagica, Linnæus
This is the commonest of the Petrels which come to our shores to breed, for as a rule these birds live far out at sea and only visit the shore to breed or when driven inland by stress of weather or on migration. About their migrations little or nothing is known, but in October and November this species regularly strikes many of our lighthouses and lightships, being attracted by the light. It is found along the whole of the countries fringing the Atlantic, and nests from the Faroes southwards, and also along the shores of the western end of the Mediterranean.
The single white egg is deposited during the latter half of June down holes in heaps of stones, in rabbit-burrows, or in any other spot affording suitable concealment. Incubation, which is probably undertaken by both sexes, lasts about thirty-five days, the nestling when hatched being covered with long black down. Their food consists of crustaceans, small fish, and fatty matter of any kind. They are nocturnal, during the breeding season at all events, only leaving their retreat after dark and returning before dawn, so that it is very difficult to detect their presence. The sitting bird, however, utters a curious note while sitting, and a strong musky odour pervades the burrow, so that by this means the nest may frequently be found. If handled, the bird emits a greenish oil.
In England it only nests sparingly on the coast of Wales and in the Scilly Islands, but in Scotland and Ireland its breeding places are numerous.
The adult is sooty black all over, but the bases of the tail coverts are white and the edges of the wing coverts are slightly edged with white. Length 6·5 in.; wing 4·7 in.