Plate 346

Black-Throated Diver

One of the most remarkable circumstances relative to this beautiful bird, which is intermediate between the Red-throated Diver and the Loon, is the extraordinary extent to which the wanderings of the young are carried in autumn and winter. It breeds in the remote regions of the north, from which many of the old birds, it would seem, do not remove far, while the young, as soon as they are able to travel, take to wing and disperse, spreading not only over the greater part of the United States, but beyond their south-western limits. In Texas I saw individuals of this species as late as the middle of April 1837; and I find it enumerated in a list of the birds observed by Mr. J. K. TOWNSEND on the Columbia river, where he also met with Colymbus glacialis. Its ramblings over a considerable portion of northern and eastern Europe have equally been noted, and it has been found breeding in the extreme north of Scotland. 

For many years I knew the young of this bird only by the name "Imber Diver," applied by BEWICK to that of another species, and now have pleasure in looking upon a drawing of mine, made about thirty years ago, with that appellation attached to it. Very few old birds in full plumage have been procured within the limits of the United States, and none, in as far as I know, farther south than the Capes of Delaware. 

No sooner has the foliage of the trees that border our western waters begun to drop and float on the gentle current of the fair Ohio, than the Black-throated Diver makes its appearance there, moving slowly with the stream. The Mississippi, Missouri, and their tributaries, are at the same period supplied with these birds. Along our eastern and southern shores they are seen from the end of autumn until spring. 

Whilst in Labrador, I saw a few pairs courting on wing, much in the manner of the Red-throated Diver; but all our exertions failed to procure any of the nests, which I therefore think must have been placed farther inland than those of the Loon or Red-throated Diver. I observed however, that in their general habits they greatly resemble those species, for on alighting on the water, they at once immerse their bills, as if for the purpose of ascertaining whether it yields a supply of suitable food, and afterwards raise themselves and beat their wings. 

This species has almost as powerful a flight as the Great Northern Diver or Loon, and I think shoots through the air with even greater velocity. When flying it moves its wings rapidly and continuously, and has the neck and feet stretched out to their full length. I well recollect that while I was standing near the shore of a large inlet in South Carolina, one of these birds, being shot while passing over my head at full speed, did not, on account of the impetus, reach the ground until upwards of twenty yards beyond me. They are equally expert at diving, and fully as much so in eluding the pursuit of their enemies when wounded. I saw my friend Mr. HARRIS bring down one from on wing, on which NAPOLEON COSTE, and WILLIAM TAYLOR, captains of the revenue cutter and tender of which we had the use, paddled in pursuit of it in a light canoe; but, although they advanced with all the address of Indians, they proved unsuccessful, for after following it both in the Bay of Cayo Island, and in the Gulf of Mexico, for nearly an hour, they were obliged to return without it, having found it apparently not in the least fatigued, although it had dived sufficiently often to travel above two miles, shifting its course at each immersion. It is curious to observe how carefully these birds avoid the danger of sudden storms or heavy gales. On such occasions, I have seen Divers at once seek the lee of rocks, islands, or artificial embankments, where they could not only remain in security, but also procure their accustomed food. At other times, when striving against the tempest, they dive headlong from on wing, and are sure to reappear in the smooth parts which sailors term the trough. 

I once caught one of these birds on the Ohio, it having been incapacitated from diving by having swallowed a large mussel, which stuck in its throat. It was kept for several days, but refused food of every kind, exhibited much bad humour, struck with its bill, and died of inanition. The food of this species consists of fish, aquatic reptiles, testaceous mollusca, and all sorts of small crustaceous animals. Its flesh resembles that of the Loon, and is equally unfit to be eaten. 

The eggs, which are sometimes two, more frequently three, average three inches in length, by two in their greatest breadth, which is about a third of the whole length distant from the extremity. Their form is that of the Red-throated Diver, which however they exceed in size. The shell is rather thick, the surface roughish, the ground colour chocolate tinged with olive, sparingly spotted at the larger end with very dark umber and black, and sprinkled all over with very small dots of the same colour. 

I have represented an adult male, a female, and a young bird. 

COLYMBUS ARCTICUS, Bonap. Syn., p. 420. 
COLYMBUS ARCTICUS, Black-throated Diver, Swains. and Rich. F. Bor. Amer.,vol. ii. p. 475. 
BLACK-THROATED DIVER, Nutt. Man., vol. ii. p. 517. 
BLACK-THROATED DIVER, Colymbus arcticus, Aud. Orn. Biog., vol. iv. p. 345. 

Male, 29, 39 1/2. 

The young range throughout the interior and along the coast as far as Texas, in autumn and winter. Adult in full plumage very rare. Breeds in high latitudes. Columbia river. 

Adult Male. 

Bill as long as the head, straight, stout, higher than broad at the base, much compressed toward the end, and tapering to a point. Upper mandible with the dorsal line descending and considerably convex toward the end, the ridge convex, narrowed toward the point, the sides convex beyond the nostrils, the edges involute for half their length in the middle, direct at the base and toward the end, the tip narrow and sharpish. Nasal groove rather long and narrowed; nostrils sub-basal, linear, direct, pervious. Lower mandible with the angle extremely narrow, and very long, the dorsal line ascending and very slightly convex, the ridge convex and narrow, the edges sharp and involute, the tip attenuated. 

Head of moderate size, oblong, narrowed before. Neck rather long and thick. Eyes of moderate size. Body elongated, much depressed, of an elliptical form viewed from above. Wings small. Feet short, rather large, placed very far back; tibia almost entirely concealed; tarsus short, exceedingly compressed, sharp-edged before and behind, covered all over with reticulated angular scales, hind toe extremely small, externally marginate, connected with the second for half its length by a membrane, which extends, narrowing, to the end; the anterior toes connected by articulated membranes, the fourth or outer longest, the third a little shorter, the second considerably shorter than the third; all covered above with numerous narrow scutella; the second toe with a free two-lobed membrane, the claws very small, depressed, blunt. 

Plumage short and dense, of the head and neck very short, soft and blended; of the lower parts short, blended, stiffish, considerably glossed; of the upper compact, glossy; the feathers on the lower part of the sides of the neck much incurved, oblong, with the terminal barbs stiff; those of the fore part of the back and the scapulars straight, oblong, abrupt. Wings proportionally very small and narrow, curved; primaries strong, tapering, the first longest, the second slightly shorter, the rest rapidly graduated; secondaries very short, broad, and rounded. Tail extremely short, rounded, of eighteen feathers. 

Bill black. Iris deep bright red. Feet greyish-blue, their inner sides tinged with yellow; claws black, that of the inner toe yellowish at the base. The upper part of the head and the hind neck are light grey or hoary, the fore part and sides of the head darker. The upper parts are glossy black, tinged with green anteriorly, and shaded with brown behind. On the fore part of the back are two longitudinal bands of transverse white bars, the feathers being tipped with that colour; the scapulars, excepting the outer, are marked in the same manner with transverse rows of rather large square spots. Most of the wing-coverts have two roundish spots of white near the end. The quills are blackish-brown, tinged with grey externally, paler on the inner webs; the tail also blackish-brown. The fore neck, to the length of six and a half inches, is purplish-black, ending angularly below, and with a transverse interrupted band of linear white spots near the upper part; beyond which the sides of the neck are blackish-brown, with several longitudinal white streaks, formed by the edges of the feathers; on the lower part of the neck a broad space is occupied by these longitudinal, dusky, and white streaks, the former of which gradually become narrower. The lower parts are pure white, excepting a longitudinal band on the sides under the wing, which is dusky. 

Length to end of tail 29 inches, to end of wings 27 1/2, to end of claws 33; extent of wings 39 1/2; wing from flexure 12 3/4; tail 2 3/4; bill along the ridge 2 (5 1/2)/12, along the edge of lower mandible 3 (4 1/2)/12; tarsus 3 1/12; hind toe 8/12, its claw 2/12; second toe 3 2/12, its claw (5 1/2)/12; third toe 3 8/12, its claw 5 (5 1/2)/12; fourth toe 4 1/4, its claw (4 1/2)/12. 

Adult Female. 

The female is smaller than the male, but is similarly coloured. 

Young in winter. 

The texture of the plumage is less dense, the feathers on the neck being more downy, and those of the back oblong and rounded. The bill is light bluish-grey, dusky along the ridge; the iris brown; the feet more dusky. The upper part of the head and the hind neck are dark greyish-brown; the sides of the head greyish-white, minutely streaked with brown. The upper parts have a reticulated or scaly appearance, the feathers being brownish-black, with broad bluish-grey margins; the rump dull brownish-grey. The primaries and their coverts are brownish-black, the secondaries and tail-feathers dusky, margined with grey. The fore part of the neck is greyish-white, minutely and faintly dotted with brown, its sides below streaked with the same; the lower parts, including the under surface of the wing, pure white; the sides of the body and rump, with part of the lower tail-coverts, dusky, edged with bluish-grey. 

When in their first downy plumage, the young are of a uniform brownish-black colour. 

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