The tern has been called a sea-swallow, and he is certainly swallow-like in his slender figure, sharply forked tail, and aërial habits; but he is built on more graceful lines, with proportionately longer wings, and in his white and pearl-grey plumage is the more beautiful bird. The blood-red hue of the beak in the arctic tern gives that touch of bright colour which adds so much to the beauty of a species otherwise wholly black or white; it intensifies a black plumage, as we see in the blackbird and chough, and makes the white plumage seem more immaculate in its whiteness. The flight of the tern is unlike that of any other bird, whether of the sea or land: it is more airy, and suited to the pale, slender, aërial figure; buoyant and slightly wavering, it reminds one a little of the high, apparently uncertain, flight of some large-winged butterfly; and it is in perfect harmony, not only with the slimmer form, but with the idea of a being whose life is passed amid wind and mist and fluctuating wave. It is a rare pleasure to watch a number of these terns feeding in an inlet or bay, where the spectator can sit or lie on a cliff or jutting rock near to and on a level with the birds. They are not concerned at his presence, but, intent on their prey, pass and re-pass before him so near that their round, brilliant eyes may be distinctly seen. The blood-red, dagger-like beak is pointed downwards almost constantly as the bird gazes on the water thirty or forty yards below. All at once the buoyant flight is arrested, the bird hangs motionless in mid-air, the snow-white, forked tail expanded and depressed, the slow-moving, wavering wings rapidly vibrated. In such an attitude he reminds you less of a windhover than of the humming-bird, when that little feathered fairy is seen hovering motionless above the flowers on which its eyes are fixed. Suddenly the wings partly close, and the white figure drops plumb down, with such force as to send up a shower of foam and spray as it strikes on and disappears into the water, to emerge in a moment or two with a small fish in its bill.
The terns, of which there are five breeding-species in the British Islands, are all migrants, and come to us in spring. The arctic tern ranges farthest north: it is the most common species on the coasts of Scotland and its islands; its most southern breeding-station is at the Farnes, off the coast of Northumberland. It breeds in communities sometimes numbering thousands of birds. The nests are placed very near each other, often within half a yard, among scanty grass and herbage, or on the shingle and sand of the beach, and sometimes on the bare rock. Two or three eggs are laid, greatly varying in their ground-colour, olive, buff, greyish brown, stone, and other tints being found; and the spots and blotches of blackish brown and grey may be few or many. The young birds are at first covered with a yellowish down with dark brown spots, and are very active. When the nesting-ground is entered the birds rise up, and hover in a dense cloud above the intruder’s head, their united powerful screams producing an extraordinary noise, like that of the sea on a shingled beach when the withdrawing wave drags back the pebbles with shrill and grating sounds.
In September and October the arctic tern migrates to warmer regions.
Common Tern.
Sterna fluviatilis.
Fig. 107.—Common Tern. ⅐ natural size.
Bill, legs, and feet orange-red; entire plumage as in the arctic tern, except the lower parts, which are more nearly pure white. Length, fourteen and a quarter inches.
So nearly alike are the arctic and common terns that it is hard, well-nigh impossible, in fact, to distinguish them when they are observed flying about in company. In size, manner of flight, language, and general appearance, they are identical. On a close examination the common tern is found to be slightly less slender in build, its under parts dull white instead of pale grey, its beak tipped with black and coral-red, instead of blood-red. It is doubtless owing to their similarity that the two species associate freely together at all times, and are often to be found breeding side by side. But while the arctic tern is most common in the north, from the Shetlands, Orkneys, and Hebrides, to the coast of Northumberland on the one side of the country, and of Lancashire on the other, the common tern is common only on the coasts south of these two points. The nest is a slight depression, sometimes with a little dry grass for lining, placed on the shingle of the beach; the three eggs are yellowish stone, grey, or olive colour, spotted and blotched with dark brown and grey.