There has never been a keener eye than Audubon's, though there have been more discriminative ears. Nuttall, for instance is far more happy in his descriptions of the songs and notes of birds, and more to be relied upon. Audubon thinks the song of the Louisiana water-thrush equal to that of the European nightingale, and, as he had heard both birds, one would think was prepared to judge. Yet he has, no doubt, overrated the one and underrated the other. The song of the water-thrush is very brief, compared with the philomel's, and its quality is brightness and vivacity, while that of the latter bird, if the books are to be credited, is melody and harmony. Again, he says the song of the blue grosbeak resembles the bobolink's, which it does about as much as the two birds resemble each other in color; one is black and white and the other is blue. The song of the wood-wagtail, he says, consists of a "short succession of simple notes beginning with emphasis and gradually falling." The truth is, they run up the scale instead of down, beginning low and ending in a shriek.
Yet considering the extent of Audubon's work, the wonder is the errors are so few. I can at this moment recall but one observation of his, the contrary of which I have proved to be true. In his account of the bobolink he makes a point of the fact that, in returning south in the fall, they do not travel by night as they do when moving north in the spring. In Washington I have heard their calls as they flew over at night for four successive autumns. As he devoted the whole of a long life to the subject, and figured and described over four hundred species, one feels a real triumph on finding in our common woods a bird not described in his work. I have seen but two. Walking in the woods one day in early fall, in the vicinity of West Point, I started up a thrush that was sitting on the ground. It alighted on a branch a few yards off, and looked new to me. I thought I had never before seen so long-legged a thrush. I shot it, and saw that it was a new acquaintance. Its peculiarities were its broad, square tail; the length of its legs, which were three and three quarters inches from the end of the middle toe to the hip-joint; and the deep uniform olive-brown of the upper parts, and the gray of the lower. It proved to be the gray-cheeked thrush, named and first described by Professor Baird. But little seems to be known concerning it, except that it breeds in the far north, even on the shores of the Arctic Ocean. I would go a good way to hear its song.
The present season I met with a pair of them near Washington, as mentioned above. In size this bird approaches the wood thrush, being larger than either the hermit or the veery; unlike all other species, no part of its plumage has a tawny or yellowish tinge. The other specimen was the northern or small water-thrush, cousin-german to the oven-bird and the half-brother to the Louisiana water-thrush or wagtail. I found it at the head of the Delaware, where it evidently had a nest. It usually breeds much further north. It has a strong, clear warble, which at once suggests the song of its congener. I have not been able to find any account of this particular species in the books, though it seems to be well known.
More recent writers and explorers have added to Audubon's list over three hundred new species, the greater number of which belong to the northern and western parts of the continent. Audubon's observations were confined mainly to the Atlantic and Gulf States and the adjacent islands; hence the Western or Pacific birds were but little known to him, and are only briefly mentioned in his works.
It is, by the way, a little remarkable how many of the Western birds seem merely duplicates of the Eastern. Thus, the varied thrush of the West is our robin, a little differently marked; and the red-shafted woodpecker is our golden-wing, or high-hole, colored red instead of yellow. There is also a Western chickadee, a Western chewink, a Western blue jay, a Western bluebird, a Western song sparrow, Western grouse, quail, hen-hawk, etc.
One of the most remarkable birds of the West seems to be a species of skylark, met with on the plains of Dakota, which mounts to the height of three or four hundred feet, and showers down its ecstatic notes. It is evidently akin to several of our Eastern species.
A correspondent, writing to me from the country one September, said: "I have observed recently a new species of bird here. They alight upon the buildings and fences as well as upon the ground. They are walkers." In a few days he obtained one and sent me the skin. It proved to be what I had anticipated, namely the American pipit, or titlark, a slender brown bird, about the size of the sparrow, which passes through the States in the fall and spring, to and from its breeding haunts in the far north. They generally appear by twos and threes, or in small loose flocks, searching for food on banks and plowed ground. As they fly up, they show two or three white quills in the tail, like the vesper sparrow. Flying over, they utter a single chirp or cry every few rods. They breed in the bleak, moss-covered rocks of Labrador. It is reported that their eggs have also been found in Vermont, and I feel quite certain that I saw this bird in the Adirondack Mountains in the month of August. The male launches into the air, and gives forth a brief but melodious song, after the manner of all larks. They are walkers. This is a characteristic of but few of our land-birds. By far the greater number are hoppers. Note the track of the common snowbird; the feet are not placed one in front of the other, as in the track of the crow or partridge, but side and side. The sparrows, thrushes, warblers, woodpeckers, buntings, etc., are all hoppers. On the other hand, all aquatic or semi-aquatic birds are walkers. The plovers and sandpipers and snips run rapidly. Among the land-birds, the grouse, pigeons, quails, larks and various blackbirds walk. The swallows walk, also, whenever they use their feet at all, but very awkwardly. The larks walk with ease and grace. Note the meadowlarks strutting about all day in the meadows.
Besides being walkers, the larks, or birds allied to the larks, all sing upon the wing, usually poised or circling in the air, with a hovering, tremulous flight. The meadowlark occasionally does this in the early part of the season. At such times its long-drawn note or whistle becomes a rich, amorous warble.
The bobolink, also, has both characteristics, and, notwithstanding the difference of form and build, etc., is very suggestive of the English skylark, as it figures in the books, and is, no doubt, fully its equal as a songster.
Of our small wood-birds we have three varieties east of the Mississippi, closely related to each other, which I have already spoken of, and which walk, and sing, more or less, on the wing, namely the two species of water-thrush or wagtails, and the oven-bird or wood-wagtail. The latter is the most common, and few observers of the birds can have failed to notice its easy, gliding walk. Its other lark trait, namely singing in the air, seems not to have been observed by any other naturalist. Yet it is a well-established characteristic, and may be verified by any person who will spend a half hour in the woods where this bird abounds on some June afternoon or evening. I hear it very frequently after sundown, when the ecstatic singer can hardly be distinguished against the sky. I know of a high, bald-top mountain where I have sat late in the afternoon and heard them as often as one every minute. Sometimes the bird would be far below me, sometimes near at hand; and very frequently the singer would be hovering a hundred feet above the summit. He would start from the trees on one side of the open space, reach his climax in the air, and plunge down on the other side. His descent after the song is finished is very rapid, and precisely like that of the titlark when it sweeps down from its course to alight on the ground.