Part 54

THE HERRING GULL Larus argentatus, J. F. Gmelin

This is the commonest of all our Gulls, and may be found abundantly throughout the year, round all our coasts. It nests in colonies, usually on the ledges of precipitous cliffs, although small low islets are occasionally resorted to. The nest is composed of grass, seaweed, and other vegetable débris, and the eggs, three in number, are greenish brown with brown and grey markings, but they are not infrequently of a uniform pale blue. Incubation is undertaken by both sexes. The young as a rule remain in or near the nest till fully fledged, but when the nest is low down near the shore they leave it much sooner. The Herring Gull is practically omnivorous; fish, rats, crustacea, and garbage thrown up by the tide are all equally appreciated, and when nesting near colonies of Guillemots and Cormorants it systematically hunts the ledges and devours any uncovered eggs it can find. During the nesting season it is very noisy and utters a variety of cries; at times the head is bent right down and suddenly thrown up in the air with a loud "ollick, ollick," which cry is taken and repeated all over the colony. Young Gulls first commence to utter this note, which is not peculiar to the nesting season or to this species, at about three months old. If the colony be approached the birds utter a short "ow-ow"; the pairing note is a deep "mau," not unlike a cat's "miau," and a soft purring "ououou," the latter note being uttered while the bird sits down and toys with grass or other material at hand.

The adult in summer has the mantle French grey, secondaries grey tipped with white, outer primaries black with white tips and large subapical "mirrors." The rest of the plumage is white. Bill yellow with a red patch at the basal angle. Legs flesh-coloured. The female is said to be smaller than the male, but the difference is not always very apparent. In winter the head and neck are streaked with brownish.

The young in the first autumn are mottled all over with pale brown. They do not become fully adult until their fourth year, though they may sometimes breed in their third year. The adult plumage is assumed gradually, and there is much individual variation both as regards the time and method in which it is assumed. As a rule, however, some grey feathers appear on the back during the first summer; after the second autumn moult the under parts are chiefly white flecked with brown, but the back is chiefly brown. In their second summer much of the brown on the head and under parts is lost, the mantle becomes very grey, and the bill begins to show signs of yellow. The wing coverts and tail are, however, still very mottled.

After the third autumn moult the under parts, head, and neck are much as in the adult birds but more thickly mottled, the back chiefly grey, but the wing coverts, wings, and tail are still very brownish. In their third summer they are practically in adult plumage except for the wings and tail and a remnant of black on the bill. After the fourth autumn moult they are in full adult plumage except that the bill may still show some traces of black and occasionally the tail has some brown flecks, but by the time their fourth summer comes round they are in full adult plumage and breed.

Immature birds are seldom seen among colonies of adults during the summer, and it is still somewhat doubtful where they spend the summer; possibly round some islets out at sea where food is plentiful. Length 24 in.; wing 17 in.

THE LESSER BLACK-BACKED GULL Larus fuscus, Linnæus

Very closely allied to the Herring Gull, this species is tolerably common everywhere, but is rather more local in the breeding season. In England it nests but sparingly and only in the west, but in Scotland it becomes much more abundant, and in some districts commits considerable havoc among the game-birds on the moors.

It chooses for its breeding-quarters some grassy slope on the top of the cliffs or on an islet in one of the numerous firths in the west of Scotland. In Ireland it is generally distributed and nests sparingly round the coast. In all its habits this species so closely resembles the Herring Gull that further description is unnecessary.

The adult only differs from the preceding species in being black on the mantle and wing coverts, and in the colour of the legs, which are yellow. Length 22 in.; wing 16 in.

It is almost impossible to distinguish the young of this species in their first autumn.

THE GREATER BLACK-BACKED GULL Larus marinus, Linnæus

This species may be found during the winter on almost any part of our shores, but it is by no means so abundant as the Herring Gull.

As a breeding species in England it is rather scarce, chiefly owing to lack of suitable places, but in Scotland it is abundant. It is a bold and majestic species, with a fine soaring flight, but we must acknowledge that it is terribly destructive to weakly lambs and young water-fowl. Practically omnivorous, nothing comes amiss to this rapacious bird, and its food consists largely of carrion and other refuse of the shore. Although it has often been denied, this and other species of Gulls can completely immerse themselves and pick up food from the bottom in at least three feet of water, and we have repeatedly observed them do so in captivity. Having marked some food at the bottom of the water, they rise to a height of about four feet and forcibly precipitate themselves into the water with half-open wings; they are nevertheless extremely buoyant, and occasionally bob up on to the surface again before they have attained their object.

An isolated "stack" or islet in a loch is commandeered by a pair of these birds for their summer home. The nest, composed of grass and rubbish, is usually placed on the highest point. They lay two or three eggs, which are stone buff in colour, blotched and spotted with light brown and grey.

The most usual note is a deep "ow, ow, ow." In plumage the adult is almost the counterpart of the preceding, but the legs are flesh-coloured. Length 23 in.; wing 19 in.

The young are mottled and barred with various shades of brown and buff, but are rather lighter in colour than those of the Herring Gull. The adult plumage is assumed by precisely the same stages as in the other species, and they may occasionally become fully adult in their third summer.

THE GLAUCOUS GULL Larus glaucus, O. Fabricius

This large white-winged Gull is an annual visitor to the north of Scotland, but southwards it becomes scarcer, and it is only in very severe weather that it visits the south of England. Its breeding range is circumpolar, its nearest breeding-place to our shores being in Iceland.

The mantle and wings are pearl-grey, with white tips to the secondaries and outermost webs of the quills. Orbital ring vermilion. Legs pink. Immature birds are whitish uniformly and thickly mottled with ash grey. Length 29 in.; wing 18 in.

THE ICELAND GULL Larus leucopterus, Faber

This species is very closely allied in plumage and habits to the preceding. It is a winter visitor to the shores of Scotland, only coming south in severe weather. It breeds on Jan Mayen Islands and Greenland, and is only a winter visitor to the island whose name it bears.

Except in size it is almost a counterpart of the Glaucous Gull, but the orbital ring is flesh-coloured, and the legs yellowish. Length 22 in.; wing 16 in.

THE KITTIWAKE GULL Rissa tridactyla (Linnæus)

With the Kittiwake we come to a species of Gull which differs in its general build from those we have hitherto dealt with. It is rather shorter in the leg, which gives it a somewhat "squat" appearance, and it does not run about on land with the same facility. In correlation with this we find it to be a much more pelagic species, and though found commonly round our shores, it gets most of its food on the water and is rarely to be found among the large flocks of other Gulls that spend much of their time on the shore itself. Its food consists almost entirely of fish, in pursuit of which it dives and swims under water with ease.

It nests on the ledges of precipitous cliffs in immense colonies, and in some cases the population of these colonies must amount to very many thousands. The nest is built of seaweed and other flotsam, and is often larger than the narrow ledge on which it is placed. The eggs, two or three in number, are usually pale greyish white, blotched and zoned with ash grey and brown; the shell is rougher in texture than in the other species. They are laid very late in the season, so that it is generally July before the young are hatched. Both sexes take part in the incubation, and the young are entirely nidicolous, not leaving the nest till they are well able to fly.

In summer the adults very closely resemble the common Gull, but it is a smaller bird, and the black legs, on which the hind toe is absent, form an unfailing characteristic. In winter the nape and hind neck are grey like the mantle. Length 15·5 in.; wing 12 in.

The young bird in its first autumn has the nape greyish but darker than in the adult, and the wing coverts and inner secondaries are thickly spotted with brownish black.