British Sea Birds

by Charles Dixon

SANDWICH TERN.

This fine species—the Sterna cantiaca of Gmelin, and the S. sandvicensis of Latham—is not only the largest of the indigenous British Terns, but one of the rarest. It was formerly much more widely dispersed along our coasts, but persecution has thinned its numbers, and the seaside holiday-maker has banished it from many of its old-time haunts. Special interest attaches to this bird, because it is one of the very few species that have been first made known to science from examples obtained in the British Islands. It was first discovered in 1784, at Sandwich, on the coast of Kent, and described by Latham three years later. Alas! no longer does this beautiful Tern breed in its early haunts on the Kentish coast; it has disappeared from there, as it has from many another locality, without hope of return. The most important breeding-place of this Tern, and certainly the most accessible to the majority of observers, is situated on the famous Farne Islands; even here the bird is much less common than it used to be. There are small colonies on Walney Island, in Cumberland, in the Solway district, on Loch Lomond, in the Firth of Tay, and on the coast of Elgin. Its only known breeding-station in Ireland is in Co. Mayo.

The Sandwich Tern reaches the British coasts in April or early in May. But little is seen of this species whilst on passage, for it evidently keeps some distance from shore as a rule, or passes quickly and unobserved. The smaller Terns, for instance, are commonly seen on the coast of South Devonshire in Spring and Autumn, but I cannot recall a single strong migration of the present species in that locality. This Tern is seldom or never seen at any distance from the sea. Most of its waking time is spent in the air, flying about with easy, graceful motion, in quest of its finny prey. The Sandwich Tern, however, is nothing near so graceful looking on the wing as its smaller relatives, the heavier body, broader wings, and much less acutely forked tail giving it a heavier, more cumbersome appearance. Most of its food is obtained whilst it hovers above the sea. The way in which all the Terns feed is very pretty. They poise and hover above their finny victims, and every now and then dart downwards like a stone into the water and capture a fish, fluttering up again, or remaining for a moment to swallow their capture. A flock of Terns (of any species) fishing is one of the prettiest sights imaginable. In addition to small fish the Sandwich Tern devours crustaceans of various kinds, whilst its young are fed largely upon sand-lice and beetles. The Terns are much cleaner feeders than the Gulls, and I have never known them touch carrion or refuse. I have, however, seen them pounce down upon scraps of food thrown from a vessel. The usual call-note of the Sandwich Tern is a somewhat shrill scream.

This Tern probably pairs for life, and returns regularly every season to its old-accustomed haunts to breed. These are by preference low, rocky, or sandy islands, covered with marine herbage, varied with barer patches, and with beaches of rough shingle. Similar conditions are sought on the mainland, in a secluded spot on the coast, but an island is always preferred. The Sandwich Tern is gregarious, but its colonies, with one exception, in our islands are nowhere very extensive. This one exception is at the Farne Islands, where it has been computed the birds number upwards of a thousand pairs. As the nesting-places are visited very regularly year by year this Tern probably pairs for life. I have noticed, however, that the birds shift their actual breeding ground from time to time, using several spots in succession. One year they will nest here, another year there, on the same small island perhaps, but sometimes removing en masse to another one of the group. The nests are always placed upon the ground, either amongst the sand shingle and drifted debris, a short distance from high water mark, or amongst the sea campion, thrift, and coarse grass further inland; sometimes a bare mound on the highest part of the island is selected. Many nests are made within a small area, sometimes so close together as to render walking amongst them without treading on their contents a difficult matter. The nests are slight enough, mere hollows lined with a few bits of withered herbage, and in some cases even this simple provision is neglected. The eggs, which are laid from about the middle of May to the middle of June, are generally two in number, but sometimes three. These vary from creamy-white to rich buff in ground colour, handsomely blotched and spotted with various shades of brown and gray. During the hot June days the eggs seem to require little incubation, but there are always plenty of birds about the spot, ready to rise fluttering and screaming into the air when their breeding grounds are invaded by man. But one brood is reared in the season, yet if the first clutches of eggs be lost they will be replaced.