Part 52

This Tern still nests in small numbers round our shores, but it is extremely scarce and somewhat erratic in its choice of breeding-quarters, which often vary from year to year. It arrives very late in May, and leaves our shores as soon as the young can fly, so that it is not often met with on migration. It breeds sparingly on the coast of France, but its chief breeding-quarters are along the Atlantic coast of the United States.

In general habits it resembles its congeners, but it is an exclusively sea Tern, obtaining most of its food some distance out at sea.

In plumage it is almost indistinguishable from the two following species, but it may be recognised at all ages by the white inner margins to the primaries reaching the tip and even some little way up the outer web. The bill in the breeding season is black; legs and feet red. Length 15·5 in.; wing 9 in.

THE COMMON TERN Sterna fluviatilis, Naumann

This species arrives in May and nests in colonies round the whole of the coast as well as on some inland waters. In England it is the commonest Tern, but in Scotland and Ireland the Arctic Tern is almost if not quite as numerous, and both species may often be found nesting on the same island or beach.

Its food consists of small fish and crustacea, which it catches after the manner of all Terns by dropping down on them with closed wings from a moderate height.

They nest in colonies on rocks, shingle beaches, or near the margins of large inland waters, and very little attempt at a nest is made, though this species almost invariably gathers a few bents together. The eggs are usually three in number, often only two, and are very variable in colour, being as a rule greenish or stone buff, with brown and grey spots and markings.

The note is a sharp "kik-kik," but during the nesting season they utter a loud "ee-arre," which is rather characteristic of this species.

The young are covered with pale brown down mottled with black, and leave the nest as soon as they are hatched, but they remain near the spot until they are fully fledged and well able to fly, as they are during that period entirely dependent on their parents for food.

Soon after the young can fly, old and young gradually disperse along the coast, slowly working southwards till by the beginning of October the last straggler has left for its winter quarters in Africa.

In summer the adult has the crown of the head and nape black, the rest of the back pearl-grey; rump white; tail feathers white with greyish outer webs. Under parts white tinged with grey. Bill orange red with horn-coloured tip; legs coral red. The sexes are alike. In winter the forehead is sprinkled with white and the under parts nearly pure white. The young in its first plumage has the head white; spotted with blackish brown, the feathers of the back pale pearl-grey barred with buff or brown and tipped with white; by late autumn, however, the back is pure grey with the exception of a dark band along the carpal joint. Bill and legs yellowish. Length 14·25 in.; bill 1·7 in.; tail 6·5 in.; wing 10·5 in.

THE ARCTIC TERN Sterna macrura, Naumann

Except in a few minor points of plumage and in its distribution this species is the counterpart of the preceding one. In England it is only met with on migration, though a few pairs may nest in the north, but in Scotland it is the commonest Tern, breeding in increasing numbers northwards. In Ireland it breeds commonly, especially on the wind-swept islets of the north and west. Elsewhere it breeds in circumpolar regions, and has been met with in winter in Antarctic seas, so that it has a latitudinal range of from 82° N. to 74° S., probably the largest range recorded for any one species.

Its nesting habits are similar to those of the Common Tern, and as a rule it collects absolutely no materials for a lining, but lays its eggs in a shallow "scrape" or even on the bare rock. The eggs are indistinguishable in colour from those of the Common Tern, but are on the average slightly smaller. To the experienced ear the note is also rather different, but that difference is too slight to be expressed on paper.

This species may be distinguished from the preceding species by its blood-red bill, which is not darker at the tip, and the shorter tarsi. The under parts, especially in summer, are much darker, and the stripe on the inner web of the flight feathers is narrower and darker than in S. fluviatilis. In other respects these species are almost indistinguishable. Length 14·5 in.; bill 1·6 in.; tail 7·5 in.; wing 10 in.

THE LITTLE TERN Sterna minuta, Linnæus

This is the smallest of our Terns and is a summer visitor, breeding in fair numbers on shingle beaches round the coast but becoming scarcer in the north.

It may often be seen fishing in small parties at the tidal mouth of some small stream, especially when the tide is flowing. At such times it flies slowly towards the sea till it sees a fish, when it stops, hovers for a moment, and then drops on its prey, rising immediately from the water to resume its search; after progressing a short distance it will wheel back and return to its starting-point.

The eggs are laid on the bare sand or shingle without any attempt at a nest; they are usually three in number and of a pale stone colour spotted with grey and brown. The note is a sharp "kik."

In summer the head and nape are black, except for the forehead, which is white. Upper parts grey, tail and under parts white. Bill yellow with a black tip. Legs orange.

The young have the head white, streaked with blackish brown, mantle grey with buffish tips, under parts white. In their first autumn plumage they are very similar to the young of the Sandwich Tern, the feathers of the back being marked with black, brown, and white. Length 9 in.; wing 6·75 in.

THE SOOTY TERN Sterna fuliginosa, J. F. Gmelin

Stragglers of this tropical species have on two or three occasions been met with on our coasts.

There is a white band across the forehead, which extends backwards over the eye on each side; rest of the upper parts deep sooty black; under parts white; outer web of outer tail feathers white. Bill and legs black. Length 17 in.; bill 2·1 in.; tail 7·5 in.; wing 11·75 in.

THE NODDY Anous stolidus (Linnæus)

Like the former, this is a tropical species, which has on two occasions wandered to our shores.

The general colour is a dark chocolate brown all over except for the head, forehead, and crown, which are lavender grey. Length 16 in.; wing 10·5 in.

SABINE'S GULL Xema sabinii (Joseph Sabine)