Part 51

In plumage it is very similar to the Curlew, but may always be distinguished by having the crown of a uniform dark brown with a pale stripe down the centre. It is also a much smaller species. Length 17·5 in.; bill 3·4 in.; wing 10 in.

THE ESKIMO CURLEW Numenius borealis (J. F. Forster)

The home of this bird is in Arctic America, and some eight or nine examples have been procured in this country.

In appearance it is rather like a small Whimbrel, but it may be recognised by the absence of barring on the primaries, no white on the rump, transverse arrow-head markings on the under parts, and the axillaries being chestnut barred with brown. Length 14 in.; wing 8·25 in.

THE BLACK TERN Hydrochelidon nigra (Linnæus)

Up till the middle of last century the Black Tern was a regular summer visitor to our shores, remaining to breed in the fens and marshes of England. For the last forty years, however, it has only occurred on passage, the adult birds passing through in April and May, and flocks in immature plumage being found along the east coast in the autumn. To the west of England and Scotland it is a very irregular visitor, and the same may be said of Ireland.

It nests in colonies on inland marshes, the nest being an accumulation of decaying vegetation floating on the surface of the water. The eggs, three in number, are olive green blotched with dark brown. Its food consists largely of aquatic insects and their larvæ, dragon-flies and such like, but it also feeds readily on small fish.

South of the Baltic it breeds in suitable localities throughout Europe, migrating from its more northerly summer quarters to Africa.

The adult in summer has the head, neck, and under parts dark greyish black, the rest of the plumage slate grey, except the vent and under tail coverts, which are white. Bill black. In winter the forehead, nape, chin, throat, and under parts are white. The young resemble the adults in winter, but the upper tail coverts are lighter and the back and wing coverts are greyish mottled with brown. Length 10 in.; wing 8·5 in.

THE WHITE-WINGED BLACK TERN Hydrochelidon leucoptera (Schinz)

This species, which is nearly allied to the preceding, breeds in the marshes of Central and South-eastern Europe. It is a very scarce and irregular visitor to our eastern and south-eastern shores, especially in spring.

In habits it resembles the Black Tern, from which it may be distinguished in summer by its red bill, white tail and tail coverts, and whitish wing coverts. The young may be distinguished from those of H. nigra by their longer toes and much paler rump and tail. Length 9·5 in.; wing 8·25 in.

THE WHISKERED TERN Hydrochelidon hybrida (Pallas)

This is a more southern species than its congeners, breeding in Spain, on the delta of the Rhone, and eastwards in Turkey, Greece, and South Russia. To our shores it is a very rare visitor, some half-a-dozen specimens only having been obtained.

In summer it is not unlike the Black Tern, but it may be recognised by the bill, which is stouter and red; the black of the head and nape is sharply contrasted with the grey of the back. A broad white stripe runs backwards from the base of the bill. Chin and throat grey, shading to black on the belly. In winter the forehead and under parts are white. Length 11·5 in.; wing 9·25 in.

THE GULL-BILLED TERN Sterna anglica, Montagu

With this species we come to the true Terns or Sea-Swallows, the preceding species being known as Marsh Terns. The Gull-billed Tern is only a very scarce straggler to our shores, being a southern European species though occurring yearly as far north as Denmark.

In habits there is nothing to distinguish it from our commoner species.

In summer the adult has the whole of the upper parts, including the tail, pearl grey; head and nape dense velvety black; primaries blackish. Under parts pure white; bill and legs black. In winter the head is white streaked with black. Length 15·5 in.; wing 13 in.

THE CASPIAN TERN Sterna caspia, Pallas

This large Tern is, like the preceding, only a rare straggler to our shores. It nests in Denmark and various islands on the Baltic, as well as in the Mediterranean basin eastwards to the Aralo-Caspian area.

Plumage much as in preceding species, but the tail nearly white. Bill vermilion red; legs black. Length 20 in.; wing 16 in.

THE SANDWICH TERN Sterna cantiaca, J. F. Gmelin

This species arrives on our coasts about the middle of April and at once repairs to its breeding-stations. In England these are very few in number and mostly in the north, but occurring equally on the east and west coasts. In Scotland the colonies are rather more numerous, while Ireland can only boast of one in the north.

It nests on the bare shingle, the nests being usually placed quite close to each other. Two or three eggs of a pale stone colour, spotted and blotched with reddish brown and black, form the clutch.

Like all Terns, this bird is a powerful flier, and seizes the fish on which it feeds by plunging into the water with considerable force. Its note is a loud and harsh "kirhitt," which may be heard some way off and often enables this species to be detected when among other Terns. It leaves our shores as soon as the young are well on the wing, and though a few stragglers may occur on the coast during the autumn it is by no means a common species, and needs all the protection it can get, if it is to remain an annual summer visitor to our shores.

The adult male in summer has the crown of the head black; the rest of the upper parts pearl grey; rump, tail, and under parts white, the breast being suffused with a delicate rose tint which soon fades after death. Bill black with a yellow tip. Legs black. The female is similar but slightly smaller. In autumn the back of the head and nape are white, the latter being lightly mottled. In the young the head is white mottled with black. The feathers of the back and wing coverts have black and brownish crescentic markings and white tips. The tail is also marked with angular lines of black, the outer feather being almost entirely greyish. Length 16 in.; bill 2·5 in.; wing 12 in.

THE ROSEATE TERN Sterna dougalli, Montagu