STERNA, Lin. &c. TERN.
Bill as long as, or longer than, the head, almost straight, compressed, slender, sharp-edged, and pointed; mandibles of equal length, and the upper slightly sloping towards the tip ; nostrils in the middle of the bill, longitudinally cleft, and pervious; legs small, naked above the knee, tar sus very short, the three anterior toes connected by a membrane, the hinder detached; tail more or less short ; wings very long and pointed.
The terns are almost constantly on wing, seldom repos ing on the land, or swimming on the water. In the course of their wheeling flights, they graze the surface of the sea, or pounce down abruptly in pursuit of small fish or insects. After the first or second month, the young do not differ from the adults. They moult twice a-year, namely, in au tumn and spring ; and they breed in numerous groups, so that the nests are often nearly in contact with one another. These birds, which have been not inaptly denominated sea swallows, seem to be seldom alarmed at the approach o man. In spring, they migrate to the sea shores and the interior of countries. Their cry is incessant, shrill, and disagreeably piercing; and they are particularly clamorous when they ascend aloft in fine weather, and during the breeding season.
S. Cantiaca, Gine!. &c. S. Boysii, Lath. Sand:vicli Tern. Bill long, black, yellowish at the tip, feet short and black, height of the tarsus one inch, tail long, much fork ed, shorter than the wings. Length from fifteen to eigh teen inches. Inhabits most quarters of the world, but pe netrates into inland situations more seldom than some of the other species. It breeds on the coasts of France, 112)1 land, &c. In Kent, it appears about Sandwich and Rom ney Marsh, in the middle of April, and departs in Sep tember. It has also been ascertained to breed on the Fern Island. The female lays two or three white, or whitish eggs, marked with large and small blackish spots, or mar bled with brown and black, on the sand, among the peb bles on the beach, or on the bare rock.
S. Dougallii, Mont. Tern. .11acdougallian, or Roseate Tern. Bill entirely black ; legs orange-coloured ; tarsus nine lines long, the middle toe, including the nail, shorter than the tarsus ; tail much longer than the wings. The late Dr. Macdougal, of Glasgow, procured some individu als of this species, on the Cumbray Islands, in the Frith of Clyde, on the 24th of July, 1312.
M. de Lamotte, of Abbeville, has observed it associat ed with, and breeding along with, the hirundo, with which, or with the preceding, it had been carelessly con founded.
S. hirundo, Lin. &c. Common, or Greater Tern, or Sea Swallow. In some districts it is called the Gull Teaser, in New England, Mackerel Gull, at Hudson's Bay, Black Head, among the common people in Scotland, Pictarnie, Picketarnie, Tarney,/mew, &c. In Orkney it is commonly called Rittoch or Rippoch, and sometimes nrrick or Tarrach, and in Wales, Spurre or Skraye. Bill middle sized, red, with the tip black ; legs red ; length of the tarsus ten lines ; tail much forked, of the sante length as the wings, or even shorter. The length of the full grown bird is from thirteen to fourteen inches ; ex panse of wing about two feet ; and weight between four and five ounces. It has been observed in almost every corner of the world, and is very common even as far north as the coast of Greenland. In spring it arrives on our own shores, and sometimes roams a considerable way into the inland parts of the country, hovering about lakes and rivers. They are seen by mariners during the whole pas sage from Britain to Aladeira; and immense flocks of them are said to nestle on the small islands adjacent to the Canaries. Thousands of them likewise breed in the uninhabited islets of Orkney and Shetland, and in the holmes of the lakes in high latitudes. They are common in the Isle of May, in the Frith of Forth, where, when split and broiled, they are reckoned a good relish, and their eggs, when boiled hard, and eaten cold, are deemed excellent. During the pairing season each female chooses
a warm bed of sand, on which she deposits three eggs, of a size far superior to what we should expect from a bird of her dimensions. It is also deserving of remark that these eggs are of different colours, some grey, others brown, and some of a greenish hue. Nor is the manner in they are hatched less singular; for it is, in a great measure, accomplished by the heat of the sun. If the weather be dry and warm, the female seldom sits by day, but regularly resumes her maternal functions about the time that the solar influence begins to decline. The young are not all protruded at the same time, but in the order in which the eggs were laid, and at the interval of a day between each of the three birds. If, however, during the period of laying, the weather should prove cold or rainy, the same consequence does not follow; for then the eggs that were first deposited have not been forwarded by the action of the sun-beams. The young terns are no sooner excluded from the shell than they leave the nest, and follow the parent birds, which supply them with small morsels of those fishes on which they themselves feed. As only one bird, however, appears the first day, it is led back in the evening to the nest, where the female sits to complete the hatching of the remaining two. There it shelters itself beneath her wings, and on the second even ing finds a new companion. On the third the whole fami ly is produced, and becomes, front that time, independent of further clutching ; for the birds, by creeping close to gether, communicate a sufficient degree of heat to one an other. During the whole period of incubation, the parents display great solicitude for the safety of their eggs and their young. Should a person then approach their nest, both parents tumble down from the air, and flutter about him, uttering, all the while, piercing screams, expressive of their fear, anxiety, or rage. These parental cares, how ever, soon cease, the young soon becoming capable of picking their food, when provided for them. For a few days at first they are fed by the mother's bill; but after wards, what food the parents provide, they bestow without ever alighting on the ground. Fond of indulging in their airy excursions, they drop the food down on the young that are waiting below, and ready to receive it. Even then, however, the ties of parental affection are not severed, for the old birds, far above, still continue to watch over their offspring, and to warn them of the approach of danger by their cries, on hearing which, the young instantly squat down on the sand, where they continue motionless, till, the silence of their parents, their apprehensions are re moved. Their colour so nearly resembles that of the sand that it would be difficult to find them were their pursuers not directed to the spot by those very cries by which the parents mean to protect them. The terns are provided with very large wings, from which circumstance the young are not soon able to fly, six weeks elapsing before their wings have attained sufficient length to accommodate them for flight ; and during this period of nonage and in capacity, the parents continue to shower down plentiful supplies of food to their young, who already begin to fight and dispute for their prey, betraying that insatiable glut tony which characterizes their race. The mature birds are the most active fishers of all the aquatic tribes, instan taneously darting on their victim, which they descry from a great height in the air. Having dived and caught the booty, they as suddenly rise again to their former eleva tion. The fish is so completely digested in about an hour that the bird is ready for a fresh meal. By persecuting the smaller gulls, the terns sometimes oblige them to dis gorge their food ; but they, in turn, are occasionally treat ed in the same unceremonious manner by the arctic gull.