As no account of this species exists in the Fauna Boreali-Americana, it is to be supposed that it is not met with beyond the western shores of Labrador, where however I found it in abundance and breeding, in the beginning of June 1833. On the 14th of August following I observed them at Newfoundland, moving southward in detached parties of old and young, against a strong breeze, and uttering their clamorous cries. Again, in the end of April 1837, hundreds of pairs were breeding on the islands of Galveston Bay in Texas, the numerous specimens which I then examined exhibiting no difference from those obtained in Labrador and in our Middle Districts. Nay, once, in the middle of June, while wading through the quick-sands of Bayou Sara in Louisiana, I came to a high and dry sand-bar where I picked up several eggs belonging to three pairs of birds of this species, although the distance was about two hundred miles from the sea in a direct line. I have at various times observed this Tern on the waters of the Ohio in autumn, and now and then in spring, at the latter period in company with the Short-tailed Tern, Sterna nigra, and have again met with it on the shores of Lake Erie. I have also found it in winter on the eastern coast of the Floridas, but in small numbers. Few birds indeed seem to me to be so irregular in their migratory movements, for they appear to stop at any convenient breeding place from Texas to Labrador.
This species in some of its habits resembles the Marsh Tern, of Wilson, which I feel certain is the Sterna anglica of Montagu. The resemblance is especially manifest in the peculiar manner in which it seizes insects while on wing over the pools of salt marshes and elsewhere, where it is fond of rambling whenever the weather is at all fine or pleasantly warm. It then plunges toward the ground or the water, and, like a true Flycatcher, snatches its prey unawares from the tops of the grasses, or whilst flying over the shallow green-mantled pools.
Few birds are more gentle than this delicate species is at times; for, apparently unaware of danger from the vicinity of man, it allows him to approach within a few yards, whether it be on wing or on the ground. Indeed, in the latter case, I have seen it when gorged so reluctant to fly off that I have more than once thought it was asleep, although on coming up I was always disappointed in my attempts to catch it. Nothing can exceed the lightness of the flight of this bird, which seems to me to be among water-fowls, the analogue of the Humming-bird. They move with great swiftness at times, at others balance themselves like hawks over their prey, then dart with the velocity of thought to procure the tiny fry beneath the surface of the waters. When you invade their breeding place, they will sometimes sweep far away, and suddenly return, coming so near as almost to strike you. While travelling, their light but firm flight is wonderfully sustained; and on hearing and seeing them on such occasions, one is tempted to believe them to be the happiest of the happy. They seem as if marshalled and proceeding to a merry-making, so gaily do they dance along, as if to the music of their own lively cries. Now you see the whole group suddenly check their onward speed, hover over a deep eddy supplied with numberless shrimps, and dash headlong on their prey. Up rises the little thing with the shrimp in its bill, and again down it plunges; and its movements are so light and graceful that you look on with pleasure, and are in no haste to depart. Should this scene be enacted while they have young in their company, the latter await in the air the rise of their parents, meet them, and receive the food from them. When all are satiated, they proceed on their journey, stopping at another similar but distant place.
Although along our Southern and Middle Districts, the Least Tern merely scoops a very slight hollow in which to deposit its eggs, doing this from the first of April to the first of June, according to the latitude of the place, those which I found breeding on the coast of Labrador had formed very snug nests, composed of short fragments of dry moss, well matted together, and nearly of the size of that of the American Robin, Turdus migratorius; while those met with on the islands near the Bay of Galveston, were observed to have laid their eggs upon the dry drifted weeds which appeared to have been gathered by them for the purpose. The nests are generally placed out of reach of the tides, but on some occasions I have known the hopes of a whole colony destroyed by the sudden overflow of their selected places caused by a severe gale, and have observed that, on such occasions, their clamour was as great as if they had been robbed of their eggs by man.
The number of eggs deposited by this species is more frequently three than four. Like those of most other Terns, they differ somewhat in size and markings, although I never found any so large as those described by Wilson, who states that they measure nearly an inch and three quarters in length, which would better agree with the eggs of the Common Tern. The average of a basketful was found to be one inch and two and a half eighths in length, by seven and a half eighths in breadth. They are rather pointed at the smaller end, and their ground colour is pale yellowish-white, blotched with irregular dark brown spots, intermixed with others of a dull purplish tint.
I have found this Tern breeding among Shearwaters along the Florida coast; and my friend the Reverend John Bachman has observed the same circumstance on the “Bird’s Banks,” on the coasts of South Carolina, where it is abundant, as well as on Sullivan Island.
The common note of our Least Tern resembles that of the Barn Swallow when disturbed about its nest, being as smartly and rapidly repeated at times. When it proves convenient for it to alight on the ground or on a sand-beach, after it has secured a prawn or small fish, it does so, and there devours its prey piecemeal, but it more usually swallows it on wing. On the ground it walks prettily, with short steps, keeping its tail somewhat raised.
Sterna minuta, Linn. Syst. Nat. vol. i. p. 228.—Lath. Ind. Ornith. vol. ii. p. 809.—Ch. Bonaparte, Synopsis of Birds of United States, p. 355.
Lesser Tern, Sterna minuta, Wils. Amer. Ornith. vol. vii. p. 80, pl. 60, fig. 2.
Silvery Tern, Nuttall, Manual, vol. ii. p. 280.