137 AMERICAN DIPPER
|The specimens from which the figures here given have been taken,
were procured on the Rocky Mountains, on the 15th of June, when they
were supposed to be breeding, so that they were probably adults in full
plumage. Having little taste for critical discussions, I shall refrain
from inflicting on the reader a long and elaborate review of all that
has been said on the subject of this interesting but little-known bird,
which was figured by the Prince of MUSIGNANO from a specimen obtained
near the sources of the Athabasca river, under the name of Cinclus
Pallasii; and has been described by Mr. SWAINSON, first as C. Mexicanus,
and again, in the Fauna Boreali-Americana, as C. Americanus.
Unfortunately very little is known respecting the habits of the American
Dipper, which, however, being in form and size so very similar to that
of Europe, probably resembles it in its mode of life. I will therefore
endeavour to supply the deficiency by presenting you with some extracts
from the history of the latter, as given by my friend WILLIAM
MACGILLIVRAY, of Edinburgh, who, among the wild hills of his native
country, has studied its habits with a zeal and acuteness certainly not
exceeded by those of any ornithologist.
"This bird having in a particular manner engaged my attention in the course of my many rambles, I have been enabled to trace its history in a satisfactory degree, so that the account here presented of it I consider as amongst the most accurate of those which I have written.
"It frequents the sides of rivers and streams of inferior magnitude, especially such as are clear and rapid, with pebbly or rocky margins. I have met with it in every part of Scotland, as well as in the hilly parts of Cumberland and Westmoreland, and it is said by MONTAGU to occur in Wales and Devonshire. In Scotland it is not peculiar to the mountainous regions, being found in the lowest parts of the Lothians, as well as on the alpine rills of the Grampians, and other elevated tracts, but it is generally more abundant in hilly ground, and, although never common in any district, is nowhere more plentiful than on the Tweed and its tributaries, in the pastoral counties of Peebles and Selkirk. It is also a well-known inhabitant of all the larger Hebrides. It is not only a permanent resident, but seldom shifts its station to any great extent, excepting during continued frosts, when it descends along the streams, and is seen flitting about by the rapids and falls. Mill-dams are also favourite resorts, especially in winter and spring. On lakes having a muddy or peaty bottom I have never observed it; but it may sometimes be seen on those which are shallow and pebbly at the margins, as on St. Mary's Loch in Yarrow, where I have shot it.
"The flight of the Dipper is steady, direct, and rapid, like that of the Kingfisher, being effected by regularly timed and quick beats of the wings, without intermissions or sailings. It perches on stones or projecting crags by the sides of streams, or in the water, where it may be seen frequently inclining the breast downwards, and jerking up the tail, much in the manner of the Wheatear and Stonechat, and still more of the Wren; its legs bent, its neck retracted, and its wings slightly drooping. It plunges into the water, not dreading the force of the current, dives, and makes its way beneath the surface, generally moving against the stream, and often with surprising speed. It does not, however, immerse itself head foremost from on high like the Kingfisher, the Tern, or the Gannet; but either walks out into the water, or alights upon its surface, and then plunges like an Auk or a Guillemot, slightly opening its wings, and disappearing with an agility and dexterity that indicate its proficiency in diving. I have seen it moving under water in situations where I could observe it with certainty, and I readily perceived that its actions were precisely similar to those of the Divers, Mergansers, and Cormorants, which I have often watched from an eminence, as they pursued the shoals of sand-eels along the sandy shores of the Hebrides. It in fact flew, not merely using the wing, from the carpal joint, but extending it considerably and employing its whole extent, just as if advancing in the air. The general direction of the body in these circumstances is obliquely downwards; and great force is evidently used to counteract the effects of gravity, the bird finding it difficult to keep itself at the bottom, and when it relaxes its efforts coming to the surface like a cork. MONTAGU has well described the appearance which it presents under such circumstances:--"In one or two instances, where we have been able to perceive it under water, it appeared to tumble about in a very extraordinary manner, with its head downwards, as if picking something; and at the same time great exertion was used, both by the wings and legs." This tumbling, however, is observed only when it is engaged in a strong current, and its appearance is greatly magnified by the unequal refraction caused by the varying inequalities of the surface of the water. When searching for food, it does not proceed to great distances under water; but, alighting on some spot, sinks, and soon reappears in the immediate neighbourhood, when it either dives again, or rises on wing to drop somewhere else on the stream, or settle on a stone. Often from a shelving crag or large stone it may be seen making short incursions into the water, running out with quiet activity, and presently bobbing up to the surface, and regaining its perch by swimming or wading. The assertion of its walking in the water, on the bottom, which some persons have ventured, is not made good by observation, nor countenanced by reason and the nature of things. The Dipper is by no means a walking bird: even on land I have never seen it move more than a few steps, which it accomplished by a kind of leaping motion. Its short legs and curved claws are very ill adapted for running, but admirably calculated for securing a steady footing on slippery stones, whether above or beneath the surface of the water. Like the Kingfisher, it often remains a long time perched on a stone, but in most other respects its habits are very dissimilar.
"On these occasions it is not difficult to approach it, provided due precaution be used; but in general it is shy and easily alarmed. I have several times shot at an individual which observed me as I was quietly walking up to it; but it is not often that one remains until you come within shot. A method which I have often successfully practised was to mark the position of the bird at a distance, taking note of an object on the bank opposite to it, then make a circuit, and suddenly come upon the spot. When one has been pursued either up or down a stream for a quarter of a mile or so, it usually turns, to regain its ordinary station, when it may be shot as it dashes past.
"On being wounded the Dipper commonly plunges into the water, flies beneath its surface to the shore, and conceals itself among the stones or under the bank. In fact, on all such occasions, if enough of life remains, it is sure to hide itself, so that one requires to look sharply after it. In this respect it greatly resembles the Common Gallinule.
"The food of the Dipper is said by authors to consist of small fishes, roe, and water-insects. I have opened a great number of individuals, at all seasons of the year, but have never found any other substances in the stomach than Lymneae, Ancyli, Coleoptera, and grains of gravel. As to the ova and fry of the salmon, there is no evidence whatever that the Dipper ever swallows them; and, therefore, the persecution to which this bird has been subjected in consequence of the mere suspicion, ought to cease until the fact be proved. That the mollusca above mentioned form a principal part of its food was never suspected, and therefore I was much pleased with making the discovery, which satisfactorily accounted to me for all the subaqueous excursions of the species."
The only original observations respecting the habits of the American Dipper that I have to present here are the following, with which I have been favoured by Mr. TOWNSEND:--"This bird inhabits the clear mountain streams in the vicinity of the Columbia river. When observed it was swimming among the rapids, occasionally flying for short distances over the surface of the water, and then diving into it, and reappearing after a long interval. Sometimes it will alight along the margin, and jerk its tail upwards like a Wren. I did not hear it utter any note. The stomach was found to contain fragments of fresh-water snails. I observed that this bird did not alight on the surface of the water, but dived immediately from the wing."
CINCLUS PALLASII, Bonap. Amer. Orn., vol. ii. p. 173.
AMERICAN DIPPER, Cinclus Americanus, Aud. Orn. Biog., vol. iv. p. 493;vol. v. p. 303.
Bill rather short, slender, slightly ascending, much compressed toward the end; upper mandible with its dorsal line slightly arched, the ridge rounded, the sides convex, the edges sharp and inflected, with an obscure notch close to the narrow slightly deflected tip; lower mandible slightly bent upwards, the angle medial and very narrow, the dorsal line ascending and slightly convex, the tip narrow and rather acute, the gape-line straight. Nostrils linear, direct, in the lower and fore part of the nasal membrane, which is covered with very short feathers. Eyes rather small; eyelids densely feathered.
The general form is short, full, and compact; the head oblong, compressed, rather small; the neck rather short; the body rather deeper than broad. Legs strong, of ordinary length; tarsus compressed, covered anteriorly with a long undivided plate and four inferior scutella, posteriorly with two long plates meeting at a very acute angle. Toes rather large and strong; the first, second, and fourth, nearly equal in length, but the first much stronger, the third much longer; the third and fourth united as far as the second joint of the latter. Claws rather long, arched, much compressed, that of the hind toe considerably larger.
Plumage very soft and blended, the feathers oblong and rounded; those about the base of the bill very short and velvety. No bristles at the base of the bill. Wings rather short, broad, convex, and rounded; the first quill very short and narrow, being about a third of the length of the second, which is shorter than the fourth, the third longest, and with the next three slightly cut out on the outer web towards the end; secondary quills long, broad, and rounded. Tail short, even, of twelve rather broad feathers, which are slightly decurved. Legs feathered to the joint, but the tarsus entirely bare.
Bill brownish-black; iris hazel; feet flesh-coloured, toes dusky towards the end; claws yellowish-grey. The general colour of the plumage is blackish-grey or deep bluish-grey; the head and neck chocolate-brown, that colour extending lower on the fore part of the neck than behind; the downy feathers of both eyelids white; the quills and tail-feathers dusky; the secondaries terminally margined with white.
Length to end of tail 7 1/2 inches; extent of wings 10 1/2; wing from flexure 3 3/4; tail 2 1/4; bill along the ridge 9/12, along the edge of lower mandible 11/12; tarsus 1 1/12; hind toe 5/12, its claw 4/12; middle toe 10/12, its claw 4/12.
The female is in all respects similar to the male.
In form, size, and proportion, the American Dipper is almost precisely similar to the European.