Black Tern

The Black Tern begins to arrive from the Mexican territories over the waters of the Western Country about the middle of April, and continues to pass for about a month. At that season I have observed it ascending the Mississippi from New Orleans to the head waters of the Ohio, then cutting over the land, and arriving at the Great Lakes, beyond which many proceed still farther northward. But I have rarely met with them along our Atlantic shores until autumn, when the young, which, like those of all other Terns with which I am acquainted, mostly keep by themselves until spring, make their appearance there. Nor did I see a single individual when on my way to Labrador, or during my visit to that country. They re-appear in the Western Country, in the course of their southern migration, in the months of September and October; but many pairs breed in the intermediate range. 

When residing at Louisville in Kentucky, I found the Black Tern abundant in the neighbourhood, breeding on the margins of ponds at a short distance from the Ohio. I also found them with nests and eggs on a pond near Vincennes, in the State of Indiana. Now, however, they have abandoned those places, and merely pass over the country on their way to and from the northern regions. 

Often have I watched their graceful, light and rapid flight, as they advanced and passed over in groups of twenty, thirty or more, from the delightful residence of my worthy friend and kind relative NICHOLAS BERTHOUD, Esq. of Shippingport, during the month of May, when Nature, opening her stores anew, benignly smiled upon the favoured land of Kentucky. The gay birds were seen ranging from the basin at the foot of the rapids to the lower part of the narrow channel which separates Sandy Island from the shore, up the clear stream and down again, plunging at short intervals into the water to seize their prey, and continuing their pleasing occupations through the whole day. When the period of reproduction arrived, they would all betake themselves to the ponds, and search along their moist shores for tufts of rank grass such as might form suitable places for their nests. One of their favourite ponds still remains in part, although a great portion of it has been drained. It is now known by the name of Hope-Distillery Pond, and lies a few hundred yards from the Ohio, but is nearly surrounded with buildings of various kinds. ALEXANDER WILSON, to whom I shewed the old nests of the Black Tern at this place, did not seem to be acquainted with the bird, and thought that they were those of some species of Rail. 

The nest is usually placed on the top of a broken tussock of the rankest grasses, of which it is itself composed, it being of a flattish form, and about two inches thick. It is enlarged or renewed every year, some nests being found to be from four to six inches in height. In some instances the water surrounds the foot of the tussock on which it is placed. They begin to lay on the first days of June. The eggs, of which the full number is four, greatly resemble in colour those of the Sandwich and Arctic Terns. When disturbed at this season, these birds are as noisy as any of the tribe; but they remain close over the place, and go to the river only at intervals to procure food. Both sexes incubate by turns, and the eggs are kept constantly covered. They average in length one inch and three-eighths, by one inch across, and are nearly of an elliptical form, being but slightly pointed at one end; their ground-colour is greenish-buff, spotted and dashed with reddish umber and black, more abundantly toward the middle. I took the trouble of counting the number of nests around the pond, and found it more than seventy. About the middle of August the young fly well, and are able to seek food for themselves. I have seen the parent birds feed them on wing in the manner of Swallows. 

They alight less frequently on the water than the larger species. On shore they walk like Swallows. During autumn they hunt for food over the wet prairies, passing low, and picking up the insects as they proceed without alighting. At this season, both old and young have become more silent. They are at all times less shy than most others of the tribe. Their principal food consists of aquatic insects and small fry, and their flesh is tolerably good. 

Since I wrote the above notice, I have been informed by my youngest son that this species was still seen about the Falls of the Ohio, in considerable numbers, a few years ago; but that, although he observed them there in spring, summer, and early autumn, he did not discover their breeding grounds, which are perhaps now farther inland than formerly. 

STERNA NIGRA, Bonap. Syn., p. 355. 
STERNA NIGRA, Black Tern, Swains. and Rich. F. Bor. Amer., vol. ii. p. 415. 
BLACK TERN or STERN, Nutt. Man., vol. ii. p. 282. 
BLACK TERN, Sterna nigra, Aud. Orn. Biog., vol. iii. p. 535; vol. v.p. 642. 

Adult, 9, 24. Young, in autumn, 7 3/4; wing, 9 8/12. 

Arrives in Texas from the south early in spring, proceeds along the coast to the Mississippi, then ascends that river and its tributaries, breeding around ponds, or along the streams; and even advances to the Fur Countries, where it also breeds. Abundant. Migratory. Occasionally along the coasts of the Middle Atlantic Districts. 


Adult Male. 

Bill about the same length as the head, slender, tapering, compressed, nearly straight, very acute. Upper mandible with the dorsal line slightly arched, the ridge convex at the base, narrowed towards the end, the sides sloping at the base, slightly convex and nearly perpendicular towards the tip, the edges sharp, the tip acute. Nasal groove reaching nearly to the middle of the mandible; nostrils basal, linear, direct, pervious. Lower mandible with the angle very narrow, acute, extending beyond the middle, the dorsal line straight, the sides erect and slightly convex, the edges sharp and slightly inflected, the tip extremely acute. 

Head of moderate size, oblong; neck rather short; body slender. Feet small; tibia bare for a short space; tarsus very short, covered anteriorly with small scutella, laterally and behind with reticular scales; toes very slender, the first extremely small, the third longest, the fourth nearly as long, the second much shorter, all scutellate above, the anterior connected by short reticulate webs, having a concave margin, and not extending much beyond the middle of the toes. Claws long, slender, arched, compressed, acute, that of hind toe smallest, of middle toe largest, and having a thin dilated inner edge. 

Plumage soft, close, blended, on the head short, on the back somewhat compact. Wings very long, narrow and pointed; primary quills tapering, the outer slightly curved inwards at the end, the first longest, the rest rapidly graduated; secondary short, broad, incurved, rounded. Tail of moderate length, emarginate, of twelve rounded feathers. 

Bill brownish-black. Iris brown. Feet reddish-brown, claws black. Head, neck, breast, sides and abdomen, greyish-black; lower tail-coverts white, lower wing-coverts bluish-grey. The general colour of the upper parts is dark bluish-grey; the outer web of the first quill greyish-black. 

Length to end of tail 9 inches, to end of wings 11; extent of wings 24; wing from flexure 8 3/4; tail 3 1/2; bill along the back 1 1/12, along the edge of lower mandible 1 5/12; tarsus 8/12; middle toe 8/12, its claw (5 1/2)/12. Weight 3 oz. 


Young Male in autumn. 

The bill, iris, and feet, nearly as in the adult. The upper parts are greyish-blue, the feathers of the fore part of the back, and especially the scapulars, brown towards the end; the upper and hind part of the head greyish-black, of which there is a darker mark behind, and another before the eye; the forehead greyish-white, as are the sides of the head, the fore neck, the breast, and the abdomen; the sides dusky-grey; the lower wing-coverts greyish-white. The quills are darker towards the end, and the first primary is black along the outer web. 

Length to end of tail 7 3/4 inches, to end of wings 9 8/12; wing from flexure 7 3/4; tail 2 10/12; bill along the ridge 11/12, along the edge of lower mandible 1 2/12; tarsus (7 1/2)/12; middle toe 8/12, its claw 3/12. 

Tongue 1 inch in length, very slender, grooved above in its whole length, tapering to a very fine horny point, which is a little slit. OEsophagus 3 1/2 inches long, 1/2 inch wide, within the thorax dilated to a very large sac, 9 twelfths in breadth. Stomach of moderate size, roundish, 8 twelfths long, 7 twelfths broad; the lateral muscles moderate, the tendons large, the epithelium dense, with large longitudinal rugae. The proventricular belt 8 twelfths in breadth. Intestine 12 1/2 inches long, from 2 twelfths to 1 twelfth in width; coeca 1 1/2 twelfths long, 1/2 twelfth wide, 1 inch 2 twelfths from the extremity; cloaca globular, 7 twelfths in width. Liver very large, the left lobe 10 twelfths long, the right 1 inch 2 twelfths. Trachea 2 inches 7 twelfths long, 2 1/2 twelfths wide, tapering to 1 twelfth; the rings slender, unossified, 102 in number. Bronchi rather wide, of 20 half rings. Muscles as in the other Terns.

For more on this species, see its entry in the Birds of North America Field Guide.