This wren is well named, for his home is among the rocks, in the crannies and niches of which his mate hides her nest so effectually that you must look long for it, and even after the most painstaking search you may not be able to find it. The little husband helps to lead you astray. He will leap upon a rock and send forth his bell-like peal, as if he were saying, "Right here, right here, here is our nest!" but when you go to the spot, he flits off to another rock and sounds the same challenge. And so you can form no idea of the nest site. My nearest approach to finding a nest was among the rocks and cliffs on the summit of a mountain a few miles from Golden, where an adult bird was seen to feed a youngster that had already flown from the nursery. It was interesting to know that the rock wrens breed at so high an alt.i.tude.

However, they are not an alpine species, none having been seen by the writer over eight thousand feet above sea-level, although they have been known to ascend to an alt.i.tude of twelve thousand feet.

The fourth member of our feathered quartette was the oddest of all. On the thirtieth of June my companion and I were riding slowly down the mountain side a few miles below Gray's Peak, which we had scaled two days before. My ear was struck by a flicker's call above us, so I dismounted from my burro, and began to clamber up the hillside.

Presently I heard a song that seemed one moment to be near at hand, the next far away, now to the right, now to the left, and anon directly above me. To my ear it was a new kind of bird minstrelsy. I climbed higher and higher, and yet the song seemed to be no nearer. It had a grosbeak-like quality, I fancied, and I hoped to find either the pine or the evening grosbeak, for both of which I had been making anxious search. The shifting of the song from point to point struck me as odd, and it was very mystifying.

Higher and higher I climbed, the mountain side being so steep that my breath came in gasps, and I was often compelled to throw myself on the ground to recover strength. At length a bird darted out from the pines several hundred feet above me, rose high into the air, circled and swung this way and that for a long time, breaking at intervals into a song which sifted down to me faintly through the blue distance. How long it remained on the wing I do not know, but it was too long for my eyes to endure the strain of watching it. Through my gla.s.s a large part of the wings showed white or yellowish-white, and seemed to be almost translucent in the blaze of the sunlight. What could this wonderful haunter of the sky be? It was scarcely possible that so roly-poly a bird as a grosbeak could perform so marvellous an exploit on the wing.

I never worked harder to earn my salary than I did to climb that steep and rugged mountain side; but at last I reached and penetrated the zone of pines, and finally, in an area covered with dead timber, standing and fallen, two feathered strangers sprang in sight, now flitting among the lower branches and now sweeping to the ground. They were not grosbeaks, that was sure; their bills were quite slender, their bodies lithe and graceful, and their tails of well-proportioned length. Save in color, they presented a decidedly thrush-like appearance, and their manners were also thrush-like.

Indeed, the colors and markings puzzled me not a little. The upper parts were brownish-gray of various shades, the wings and tail for the most part dusky, the wing-coverts, tertials, and some of the quills bordered and tipped with white, also the tail. The white of both wings and tail became quite conspicuous when they were spread. This was the feathered conundrum that flitted about before me. The birds were about the size of the hermit thrushes, but lither and suppler. They ambled about gracefully, and did not seem to be very shy, and presently one of them broke into a song--the song that I had previously heard, only it was loud and ringing and well articulated, now that I was near the singer.

Again and again they lifted their rich voices in song. When they wandered a little distance from each other, they called in affectionate tones, giving their "All's well."

Then one of them, no doubt the male, darted from a pine branch obliquely into the air, and mounted up and up and up, in a series of graceful leaps, until he was a mere speck against the blue dome, gyrating to and fro in zigzag lines, or wheeling in graceful circles, his song dribbling faintly down to me at frequent intervals. A thing of buoyancy and grace, more angel than bird, that wonderful winged creature floated about in the cerulean sky; how long I do not know, whether five minutes, or ten, or twenty, but so long that at last I flung myself upon my back and watched him until my eyes ached. He kept his wings in constant motion, the white portions making them appear filmy as the sun shone upon them.

Suddenly he bent his head, partly folded his wings, and swept down almost vertically like an arrow, alighting safe somewhere among the pines. I have seen other birds performing aerial evolutions accompanied with song, but have never known one to continue so long on the wing.

What was this wonderful bird? It was Townsend's solitaire (_Myadestes townsendii_)--a bird which is peculiar to the West, especially to the Rocky Mountains, and which belongs to the same family as the thrushes and bluebirds. No literature in my possession contains any reference to this bird's astonishing aerial flight and song, and I cannot help wondering whether other bird-students have witnessed the interesting exploit.

Subsequently I found a pair of solitaires on the plains near Arvada. The male was a powerful singer. Many of his outbursts were worthy of the mocking-bird, to some of whose runs they bore a close resemblance. He sang almost incessantly during the half day I spent in the neighborhood, my presence seeming to inspire him to the most prodigious lyrical efforts of which he was master. Sometimes he would sit on the top of a bush or a fence-post, but his favorite perches were several ridges of sand and gravel. His flight was the picture of grace, and he had a habit of lifting his wings, now one, now the other, and often both, after the manner of the mocking-bird on a chimney-top. He and his mate did not utter a chirp, but made a great to-do by singing, and finally I discovered that all the fuss was not about a nest, but about a hulking youngster that had outgrown his kilts and looked very like a brown thrasher. Neither of this second pair of solitaires performed any evolutions in the upper air; nor did another pair that I found far up a snow-clad mountain near Breckenridge, on the other side of the Continental Divide.

The scientific status of this unique bird is interesting. He is a species of the genus _Myadestes_, which belongs to the family _t.u.r.didae_, including the thrushes, stone-chats, and bluebirds, as well as the solitaires. He is therefore not a thrush, but is closely related to the genus _t.u.r.dus_, occupying the same relative position in the avi-faunal system. According to Doctor Coues the genus includes about twenty species, only one of which--the one just described--is native to the United States, the rest being found in the West Indies and Central and South America. Formerly the solitaires comprised a subfamily among the chatterers, but a later and more scientific cla.s.sification places them in a genus under the head of _t.u.r.didae_.

[Ill.u.s.tration: PLATE VIII

BROWN-CAPPED LEUCOSTICTE--_Leucosticte australis_ (Lower figure, male; upper, female)]

The range of Townsend's solitaire is from the plains of Colorado to the Pacific coast and north to British Columbia. According to Robert Ridgway, he has even been met with "casually" in Illinois. In Colorado many of the solitaires are permanent residents in the mountains, remaining there throughout the winter. Some of them, however, visit the plains during the fall, winter, and spring. In the winter they may be found from the lower valleys to an elevation of ten thousand feet, while they are known to breed as high as twelve thousand feet. The nests are placed on the ground among rocks, fallen branches and logs, and are loosely constructed of sticks and gra.s.s. From three to six eggs compose a set, the ground color being white, speckled with reddish brown. Doctor Coues says the birds feed on insects and berries, and are "capable of musical expression in an exalted degree." With this verdict the writer is in full accord.

CHECK-LIST OF COLORADO BIRDS

The following list includes all the species and varieties, so far as known to naturalists, occurring in the State of Colorado. Of course, these birds as families are not restricted to that State, and therefore the catalogue comprehends many of the species to be found in adjacent and even more remote parts of the country. Aside from the author's own observations, he is indebted for a large part of the matter comprised in this list to Professor Wells W. Cooke's pamphlet, ent.i.tled, "The Birds of Colorado," with the several appendixes, and to the invaluable manuals of Mr. Ridgway and Dr. Coues.

According to the latest information accessible to the writer, 389 species and varieties occur in Colorado, of which 243 are known to breed. This is a superb record, and is excelled by only two other States in the Union, namely, Texas and California. Colorado's splendid list is to be explained on the ground of its wonderful variety of climate, alt.i.tude, soil, and topographical features, such as its plains, foothills, lower mountains, and towering peaks and ranges, bringing within its boundaries many eastern, boreal, middle western, and far western forms.

The author's preference would have been to begin the roll with the most interesting birds, those to which he gave the largest share of his attention, namely, the oscines, but he has decided to follow the order and nomenclature of the Check-List of North American birds as arranged by the American Ornithologists' Union. In deference to the general reader, however, he has placed the English name of each bird first, then the scientific designation. The numbers correspond to the American Check-List. By noting those omitted, the reader will readily discover what species have not been found in Colorado.

1. =Western grebe.= aeCHMOPHORUS OCCIDENTALIS. Rare migrant; western species, chiefly interior regions of North America.

2. =Holboell's grebe.= COLYMBUS HOLBOELLII. Rare migrant; breeds far north; range, all of North America.

3. =Horned grebe.= COLYMBUS AURITUS. Rare migrant; range, almost the same as the last.

4. =American eared grebe.= COLYMBUS NIGRICOLLIS CALIFORNICUS. Summer resident; rare in eastern, common in western Colorado; breeds from plains to 8,000 feet; partial to alkali lakes; western species.

6. =Pied-billed grebe.= PODILYMBUS PODICEPS. Summer resident, rare; common in migration; breeds in northern part of State; sometimes winters in southern part.

7. =Loon.= GAVIA IMBER. Migrant; occasionally winter resident; not known to breed in State.

8. =Yellow-billed loon.= GAVIA ADAMSII. Migrant; rare or accidental.

9. =Black-throated loon.= GAVIA ARCTICA. Rare fall and winter visitant.

37. =Parasitic jaeger.= STERCORARIUS PARASITICUS. Fall and winter resident; rare.

40. =Kittiwake.= RISSA TRIDACTYLA. Rare or accidental in winter.

49. =Western gull.= LARUS OCCIDENTALIS. Pacific Coast bird; accidental in Colorado; only one record.

51a. =American herring gull.= LARUS ARGENTATUS SMITHSONIa.n.u.s. Rare migrant; range, the whole of North America.

53. =California gull.= LARUS CALIFORNICUS. Western species; breeds abundantly in Utah; only three records for Colorado.

54. =Ring-billed gull.= LARUS DELAWARENSIS. Not uncommon summer resident; common in migration; breeds as high as 7,500 feet; range, whole of North America.

58. =Laughing gull.= LARUS ATRICILLA. Bird of South Atlantic and Gulf States; once accidental in Colorado.

59. =Franklin's gull.= LARUS FRANKLINII. Rare migrant; range, interior of North America.

60. =Bonaparte's gull.= LARUS PHILADELPHIA. Rare migrant; not uncommon in a few localities; range, whole of North America.

62. =Sabine's gull.= XEMA SABINII. Rare winter visitant; breeds in the arctic regions.

69. =Forster's tern.= STERNA FORSTERI. Rare summer resident; common migrant; habitat, temperate North America.

71. =Arctic tern.= STERNA PARADISaeA. Very rare migrant; but two records; breeding habitat, circ.u.mpolar regions.

77. =Black tern.= HYDROCHELIDON NIGRA SURINAMENSIS. Common summer resident; both sides of range; habitat, temperate North America; in winter south as far as Brazil and Chili.

120. =Double-crested cormorant.= PHALACROCORAX DILOPHUS. Perhaps breeds in Colorado, as it breeds abundantly in Utah; all present records from eastern foothills.

125. =American white pelican.= PELECa.n.u.s ERYTHRORHYNCHOS. Once a common migrant; a few remained to breed; now rare; still noted on both sides of the range.

129. =American merganser.= MERGANSER AMERICa.n.u.s. Resident; common migrant and winter sojourner; a few breed in mountains and parks; generally distributed in North America.

130. =Red-breasted merganser.= MERGANSER SERRATOR. Rare winter sojourner; common migrant; breeds far north.

131. =Hooded merganser.= LOPHODYTES CUCULLATUS. Rare resident both summer and winter; breeds in eastern part and in the mountains; general range, North America.

132. =Mallard.= ANAS BOSCHAS. Very common in migration; common in winter; breeds below 9,000 feet, on plains as well as in mountains; general range, whole northern hemisphere.

134a. =Mottled duck.= ANAS FULVIGULA MACULOSA. Rare migrant; an eastern species, sometimes wandering west to plains.

135. =Gadwall.= CHAULELASMUS STREPERUS. Summer resident; common in migration; breeds on plains; also in sloughs and small lakes at an elevation of 11,000 feet in southern part of State; breeds abundantly at San Luis Lakes.

137. =Baldpate.= MARECA AMERICANA. Summer resident; breeds from plains to 8,000 feet.