Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.
CERTHIA FAMILIARIS AMERICANA Bonaparte
CONTRIBUTED BY WINSOR MARRETT TYLER
The brown creeper, as he hitches along the bole of a tree, looks like a fragment of detached bark that is defying the law of gravitation by moving upward over the trunk, and as he flies off to another tree he resembles a little dry leaf blown about by the wind. As he climbs up the tree, he is feeding, picking up tiny bits of food that lie finds half-hidden in the crevices of bark along his path. In his search he does not work like the woodpeckers, those skilled mechanics whose work requires the use of carpenter's tools, the drill and chisel. The creeper's success depends on painstaking scrutiny, thoroughness, and almost, it seems, conscientiousness. Edmund Selous (1901), speaking of the European tree-creeper, a bird close to ours in habit, uses the exact word to show us the creeper at work. "His head," he says, "which is as the sentient handle to a very delicate instrument, is moved with such science, such dentistry, that one feels and appreciates each turn of it."
Spring: The creeper is rather a solitary bird as we see it in its winter quarters and in spring on the way northward to its summer home. We often find it, to be sure, feeding near chickadees, nuthatches, and golden-crowned kinglets, but there seems to be no close association between it and the other members of the gathering. The creeper pays little or no attention to the birds about him and by no means always follows them in their wanderings.
There is little change in his behavior as spring advances; he is the same calm, preoccupied searcher he has been all through the winter, but before the close of March he may, on rare occasions, sing his delicate song. When we hear it—a strangely wild song for so prosaic a character—we, who live not too far from the creeper's northern forests, suspect that the singer may have a mate, or is attempting to acquire one, and if the song continues into May, and if the bird frequents a locality where the trees are broken, burned, or dying, we shall do well to look about for a nest, or the preparation for one, because the bird often breeds well to the south of its normal range, provided that the surroundings are favorable for nesting.
Ordinarily we meet but one creeper, or at most two, in a woodland of moderate extent, but Dayton Stoner (1932) states: "During May 1929 season, when the brown creeper was unusually common in several districts on the south side of Oneida Lake [New York], I often came upon small groups of three to six individuals in the woods, all within a few yards of one another. Perhaps not another individual would be seen for an hour or even during the entire morning. This apparent concentration of birds within localized areas led me to believe that a more or less concerted movement was taking place and that the species traveled in loose groups, not close enough to be termed flocks."
Courtship: The creeper's courtship appears to consist of a display of agility in the air. Once in a while we see a bird launch out from a tree and at top speed twine around it close to the bark, then dart away and twist around another tree, or weave in and out among the surrounding trees and branches. He has thrown off his staid creeper habits and has become for the time a care-free aerial sprite, giving himself up, it seems, to an orgy of speed, wild dashes, and twists and turns in the air. But after a round or two, back on the bark again, he resumes his conventional routine and becomes once more a brown creeper.
Chreswell S. Hunt (1907) describes a somewhat similar excursion through the air, associated with the pursuit of another creeper. He says:
It was on March 9, 1904, * * * that I saw two Brown Creepers engaged in this game of tag. In my experience the Brown Creeper always alights near the base of a tree trunk and then works upward, his course being a spiral one—he travels round and round as he climbs upward. In the pursuit I speak of this same program was carried out, only instead of climbing up the trunk the birds would fly up. They alighted near each other upon the tree, then number one would take wing and fly upward, describing one or two complete spirals about the trunk and again alight upon It with number two following in close pursuit. To travel in a spiral course seemed to be such a well formed habit that they could not get away from it. It was not simply a chance flight, for I saw it repeated again and again.
Nesting: There is a bit of interesting history in regard to the nesting of the brown creeper. Alexander Wilson (Wilson and Bonaparte, 1832) says: "The brown creeper builds his nest in the hollow trunk or branch of a tree, where the tree has been shivered, or a limb broken off, or where squirrels or woodpeckers have wrought out an entrance, for nature has not provided him with the means of excavating one for himself." He says nothing, however, about the nest itself. Thomas Nuttall's (1832) remarks on the situation of the nest consist, as usual, in a rephrasing of Wilson's report, but Audubon (1841a), while obviously copying Wilson iii speaking of the situation of the nest, adds that he himself has found nests, saying: "All the nests which I have seen were loosely formed of grasses and lichens of various sorts, and warmly lined with feathers, among which I in one instance found some from the abdomen of Tetrao Umbellus."
Many years later, with the idea of setting right a long-standing error of the older ornithologists as to the situation of the creeper's nest, Dr. Thomas M. Brewer (1879) published an article in the spring of 1879 in which he says:
In “North American Birds" [i.e., Baird, Brewer, and Ridgway, 1874] it is said to breed in hollow trees, in the deserted holes of Woodpeckers, and in decayed stumps and branches of trees. This statement is rather legendary than positively ascertained, and I am now inclined to somewhat modify this opinion the more so that I learn from Mr. Dresser that the European C. farniiiari8 usually places Its nest between the detached bark and the trunk of a large tree. This exactly describes the situation of the nest found in Grand Menan, and of six or seven other nests since Identified and described to me. All of these nests have been in just such situations and in no other. Instead of this being exceptional, it is probable that this is our Creeper's most usual mode of nesting, and that this is one of several reasons that unite to make this nest one so rarely discovered.
The hint contained in this article aroused the interest of William Brewster (1879), who, in the following spring, searched the region of Lake Umbagog, Maine, for creepers' nests and in the fall published an account of his investigations. "During former seasons," he says, "I had wasted much valuable time in sounding old Woodpecker's holes and natural cavities about places where the birds were evidently nesting; but, with the right clew at last in my possession, I succeeded on this occasion in finding quite a number of nests." The following description of a nest is a good example of those he found:
The tree selected was a tall dead fir that stood in the shallow water just outside the edge of the living forest, but surrounded by numbers of its equally unfortunate companions. Originally killed by Inundation, its branches had long ago yielded to the fury of the winter storms, and the various destroying agents of time had stripped off the greater part of the bark until only a few persistent scales remained to chequer the otherwise smooth, mast-like stem. One of these, In process of detachment, had started away from the trunk below, while its upper edges still retained a comparatively firm hold, and within the space thus formed the cunning little architect had constructed her nest. The whole width of the opening had first been filled with a mass of tough but slender twigs (many of them at least 6 inches in length), and upon this foundation the nest proper had been constructed. It was mainly composed of the fine inner bark of various trees, with an admixture of a little Usnea moss and a number of spiders' cocoons. The whole mass was firmly but rather loosely put together, the different particles retaining their proper position more from the adhesion of their rough surfaces than by reason of any special arrangement or Interweaving. The general shape of the structure necessarily conformed nearly with that of the space within which It was placed, but a remarkable feature was presented by the disposition of the lateral extremities. These were carried upward to a height of several inches above the middle of the nest, ending in long narrow points or horns, which gave to the whole somewhat the shape of a well-filled crescent. In the centre or lowest part of the sag thus formed was the depression for the reception of the eggs: an exceedingly neat, cup-shaped hollow, bordered by strips of soft, flesh-colored bark and lined with feathers from Ducks and other wild birds. The whole was fastened to the concave inner surface of the bark-scale rather than to the tree Itself, so that when the former was detached It readily came off with it.
With respect to their general plan of construction, all of the eight nests which I have examined were essentially similar. Indeed, the uniform character of the nesting-sites chosen by the different pairs of birds was not a little remarkable. Thus, in every single instance that came under my observation, the nest was placed on a balsam fir, though spruce, birch, or elm stubs were often much more numerous, and frequently presented equally good accommodations. Again, in no instance did the tree resorted to retain more than three or four pieces of bark, while oftentimes the scale that sheltered the nest was the only one that remained. The height varied from 5 to 15 feet, but this particular was perhaps sometimes determined more by necessity than by any individual preference, as I noticed that when several equally suitable bark-scales occurred on the same tree, the lowest was invariably the one taken. In one such case the nest was so low that I could easily look into it by standing up in my boat As before indicated, the size and shape of the different structures varied with that of the cavities in which they were placed. When the space between the bark and trunk was very narrow, the foundation of sticks was entirely dispensed with, the nest being then entirely composed of bark. Of the five examples now before me, only two are feather-lined, the remaining three being simply finished with shreds of the reddish inner fir-bark of a somewhat finer quality than those which make up the outer part of the structure. The most striking feature of all is the prolongation of the upper corners, already described. In one extreme specimen these horns rise four inches above the central cup that contains the eggs. They are, perhaps, designed to act as stays or supports, as they are firmly attached to the rough inner surface of the bark which sustains the nest.
The experience of Dr. Brewer and Mr. Brewster proved satisfactorily that creepers build their nests behind bits of loosened bark, yet there remained a good record by Professor Aughey, who in 1865 had found a nest in a knothole. Brewster (loc. cit.) investigated this record and explains it in this way:
Were it not for Professor Aughey's testimony we might fairly be inclined to suspect that all our earlier accounts of this Creeper's nesting were either founded upon hearsay or were purely fictitious. But we have this gentleman's satisfactory assurance that in Nebraska the Creeper does sometimes nest in holes in trees. Being desirous of obtaining further particulars regarding the nest mentioned by him in his paper on "The Nature of the Food of the Birds of Nebraska," and referred to by Dr. Brewer in the April Bulletin, I wrote to Professor Aughey on the subject, and the following is an extract from his very courteous reply: "In reference to Certhia familiaris, it is certain that in Nebraska, where its favorite position for nesting under scales of loose bark is in some localities difficult to obtain, it makes a nest in knot-holes. I have found two other nests in such places—one in June 1877, between Bellevue and Omaha, on the Missouri Bluffs, in a box-elder tree; another in June of the present season on Middle Creek, 4 miles from Lincoln, also in a box-elder. I have also found several in the ordinary positions where old cottonwoods or elms abounded. It is therefore my conviction that this method of nesting in knot-holes was inaugurated because of the scarcity of the ordinary positions. I could not find any tree near by where a nesting-place under bark could have been obtained In these instances of nesting in knot-holes."
The records of Macoun and Macoun (1900) may perhaps be accounted for in the same way. They say: "Have taken several nests at Ottawa, always in deserted woodpecker's holes."
A creeper's nest presents an odd appearance when it and the bark to which it adheres firmly are removed from the tree. In shape it is like a loosely hung hammock or a new moon, the horns built high up at the sides of the nest, which seems to hang suspended between them. The structure bears a striking resemblance to those little windrows that we see on a forest path after the passing of a summer shower when the flowing water has pushed along the loose twigs, leaves, and pine needles and has left them lying in long, curved heaps, crescent-shaped like the creeper's nest.
The nest is apparently built entirely by the female bird, but her mate often brings in nesting material and delivers it to her. I quote from my notes (Winsor M. Tyler, 1914) taken as I watched a pair building a nest in Lexington, Mass., in 1913:
When we first came upon the pair, the female was making long flights from the nest. She brought in hits of hark and sonic fuzzy material (fern down or caterpillar webbing). We saw her collect also hits of bark from nearby trees. Twice at least the male brought material and delivered It (bark or dead wood) to the female who was in the nest cavity. The female made half a dozen long flights, returning every 2 minutes. Then she flew eight times in the next 10 minutes to a very small dead white pine a few yards away and returned each time with one or more fine twigs. Often after returning with a twig 6 Inches long, she bad some difficulty in forcing it through the entrance hole. She was wise enough, however, to turn her head so that the twig might slip in end first. Once, when she brought in a beakful of fern down, the material kept catching on the rough bark and tripping her up, but by bending her neck backward she was able to hold the stuff clear of the mark. In her trips to the little dead pine, the Creeper always alighted on the slender trunk, but in order to reach the terminal twigs she had to hop out on the smaller branches. Sometimes, when these were very small, she perched crosswise upon them; often she crawled around them,: her hack to the earth. When perched, her tail hung straight downward, like a Phoebe's or a Brown Thrasher's when he sings. She broke off the twigs by tugging at them while perched or while fluttering in the air. * * *
The use of both the fern down and the webbing is, I believe, to bind the twigs together and to hold the nest to the bark, against which it rests. In the first nest site, If it had not been for this adhesion, the nest would have fallen to the ground of Its own weight, for its base was unsupported. * * *
The female flew to the nest with a bit of bark (2½ x ¼ Inches) then pulled from the protruding base of the nest a piece of fuzz and took It into the cavity. Five minutes later she (or her mate) crept again to the base and pulled off a bit of bark which she carried within. The economical habit of using material twice (first for the foundation and later for building the nest proper) is apparently a common practice. We saw it again and again.
Verdi Burtch (MS.) points out that the extensive killing of trees furnishes brown creepers with many sites suitable for nesting. He says: "In the very cold winter of 1903 or 1904, with water 2 to 3 feet deep in Potter Swamp, New York, the ice froze to such a depth that hundreds of trees were killed. A few years later, the bark below the water line came off, and the bark higher up split and, curling inward, made ideal nesting sites for the creepers. This was the condition in 1906 and 1907, and the creepers were quick to take advantage of it."
A similar condition prevailed in eastern Massachusetts about 1913, following an invasion of gypsy moths.
In addition to such fortuitous nesting sites as those mentioned above, there are other stations far to the south of the creeper's normal breeding range where the bird finds surroundings adapted to its nesting requirements. For example, Kennard and McKechnie (1905) found several nests in inundated white cedar swamps near the town of Canton, Massachusetts, and Dr. Arthur P. Chadbourne (1905) found a nest containing young in a similar swamp in Plymouth County, Mass. He remarks: "The conditions which determine the distribution of the Creeper in this region, are apparently a very moist, humid atmosphere, dense evergreen growth, through which the sun penetrates with difficulty, and considerable extent of wild woodland which is not disturbed by man throughout the nesting season."
Arthur Loveridge (MS.) found two deserted nests, each holding three eggs, behind the shutters of a cabin on an island in the Belgrade Lakes, Maine.
Eggs: [AUTHOR'S NOTE: The brown creeper lays four to eight eggs to a set, most commonly five or six. They are usually ovate in shape, with variations toward short-ovate, or more often toward elliptical-ovate. The ground color is generally pure white but sometimes creamy white. They are usually more or less sparingly marked with small spots, fine dots, or mere pin points; the larger spots are often concentrated in a ring about the larger end, in which case the rest of the egg has only a few fine markings; some eggs are nearly immaculate. Shades of reddish brown predominate in the markings, such as "hazel" or other bright browns, but darker browns, such as "Kaiser brown" or "liver brown," are not rare. I have seen one unusual set that was heavily marked with these darker browns in large blotches three-sixteenth of an inch long.
The measurements of 40 eggs in the United States National Museum average 15.1 by 11.8 millimeters; the eggs showing the four extremes measure 15.8 by 12.2, 15.5 by 12.7, and 1327 by 10.7 millimeters.]
Young: The nestling creeper has not far to go to reach his native bark, and in 13 or 14 days after hatching he is ready to undertake the short journey. The following note tells of a brood that I (1914) watched on their first day after leaving the nest:
The young birds left the Concord nest early on June 4 (possibly June 3). At 8 a. in., two were clinging, 30 feet from the ground, to the trunk of a living white pine tree which stood not far from the nest. One or two more were on another pine trunk. The little birds were extremely difficult to find by reason of their small size, their distance from the ground, their inconspicuous color and especially because each took a station in the dark shadow immediately below a horizontal limb. Here they remained motionless for many minutes. Later, two young birds, one following the other, moved upward by feeble hitches and perched or squatted close to the trunk in the right angle formed by the limb. In hitching over the bark, they moved almost straight upward and whenever I saw them as a silhouette against the sky, and could thus determine the point, they did not use their tails for support. The shortness of the young Creeper's tails gave to their bodies a rounded, unbird-like outline and, with their short, stubby bills of wide gape and their squatting position on the upright bark they suggested tree-toads in no small degree. Like most young birds after they leave the nest, the fledgling Creepers were more noisy than they had been the day before. They announced their whereabouts to their parents with a note not previously heard: a high sibilant call, "tssssi," or sometimes clearly divided into two syllables thus: "ts-tssi." The voice was very slightly tremulous and, although the pitch and delivery of the notes were decidedly Creeper-like, they suggested to Mr. Faxon and me a flock of Cedarbirds.
William Brewster (1938) states that the young birds "when held against the trunk of a tree instantly crept upwards using the short tail precisely in the manner of the old bird." Dayton Stoner (1932) speaks of the young creepers thus:
Below the nest, the bark clung firmly to the tree, but above, it bulged out so that it formed a canopy for the nest beneath which the young birds might have taken their first lessons in climbing.
As I stood viewing the situation in general and the young birds in particular four of them climbed into this covered space and, as I attempted to capture them, made a short flight into the surrounding vegetation. A little later I saw an adult feeding one of the youngsters clinging to the side of a tree. The young one did fairly well In its first attempts at climbing in the open, but seemed to have some difficulty in clinging to the smooth bark of the maples and moved about on these trees until it came to a little ledge of bark where it appeared more comfortable.
Cordelia J. Stanwood (MS.) estimates the incubation period as about 11 or 12 days.
Plumages: [AUTHOR'S NOTE: The young nestling is sparsely covered on feather tracts of the upper parts with dark gray down, which later adheres to the tips of the juvenal plumage. This first plumage is much like that of the adult, but the colors are paler and duller and the plumage is softer and looser; the streaks on the head and back are broader and less sharply defined and tinged brownish; the rump is paler russet, and the wing coverts are edged with pale buff; the under parts are buffy white, flecked on the chin, throat, and sides with dusky.
A partial postjuvenal molt, beginning early in August and involving all the contour plumage, wing coverts, and tail, but not the rest of the wings, produces a first winter plumage which is practically indistinguishable from that of the adult. Dr. Dwight (1900) says of this plumage: "Similar to previous plumage. Above darker, the rump much rustier, the crown and back with white shaft streaks, wing covert edgings whiter. Below, silky white, the crissum faintly cinnamon; tail olive-brown on the inner webs, Isabella color externally, a faint barring discernible, the middle pair of rectrices more broadly and less distinctly barred than in the juvenal plumage."
Adults have a complete postnuptial molt in August. Fall birds are usually darker, more suffused with buffy, especially on the flanks and under tail coverts, and the white wing markings are tinged with buffy white. Spring birds are somewhat faded above and dingy white below.]
Food: Speaking of the food of the brown creeper, W. L. MoAtee (1926a) says:
The bird must have a close and important relation with forest insects, but unfortunately studies have not yet been made that disclose the details of its food habits. However, we know that It devours weevils, leaf beetles, flat-bugs, jumping plant lice, leaf hoppers, scale insects, eggs of katydids, ants, and other small hymenoptera, sawflies, moths, caterpillars, cocoons of the leaf skeletonizers (Bucculatrix), pupae of the codling moth, spiders, and pseudoscorplons. It takes only a little vegetable food, chiefly mast. Most of the Insects the Brown Creeper is known to feed upon are Injurious to trees and we may safely reckon this small but very close associate of trees as one of their good friends.
Dayton Stoner (1932) remarks: "Most of the insects taken are highly destructive; and many of them and their eggs, and immature stages as well, are so small as to be overlooked by the majority of arborial birds. That this bird is a valuable ally of the forester and horticulturist cannot be doubted."
Francis H. Allen sends us the following note: "When feeding on the ground or on hard snow, as it occasionally does, it hops with the legs far apart and the body resting back on the tail, or apparently so. The bird in this rather pert attitude looks very different from the demure and rather humdrum creeper we usually see on the tree-trunk."
Behavior: We think of the creeper as always climbing upward over the bark in a straight or spiral course until, after reaching a fair height on the trunk, he drops to the base of another tree to ascend it in like manner. This is his ordinary way of feeding, but he often varies it. We may sometimes see him take a short hop backward to reinvestigate a crevice in the bark, or take a hop sideways to broaden the field of his research, and, as we have noted under "Nesting," a bird may visit a slender branch and even perch on it, and he may also hitch along the underside of a horizontal branch, his back to the ground. Dr. Arthur P. Chadbourne (1905) speaks of a bird making "a horizontal run sideways and most decidedly crablike," and A. Dawes DuBois (MS.) notes the action of a creeper thus: "He proceeded up the tree for a while, but soon began to search the branches, usually working outward from the trunk to the tip, and then flying back to the base of another branch. He seemed more at home on the under side of a limb than on top of it, for he went over the top only occasionally; evidently most of his food is to be found on the under side."
O. A. Stevens, of Fargo, N. Dak., in a letter to Mr. Bent, describes the behavior of creepers at his feeding station. He says: "From all our observations we feel that they are slow to change their habits. In the early winter of 1941-42, three birds appeared in the tree near our window shelf and repeatedly worked up the tree past suet, nuts, and doughnuts where other birds were feeding, but rarely paid any attention to the food. After a time they came to the window shelf and ate the chopped peanuts regularly. It was amusing to see them swallow pieces as large as a millet seed. Once I saw a creeper pound a larger piece of suet against the tree.
"Dr. W. J. Breckenridge of Minnesota told me that the creepers were fond of peanut butter put in holes of a stick. I prepared such a stick and hung it in the tree. The first results were disappointing. Once a bird sampled it and went on up the tree wiping his bill every few hops. A week or two later they were seen to visit it frequent]y, remaining for some little time. One day when I took it down, they looked for it repeatedly. The tree stands some 10 feet from the window shelf. In coming to the shelf, the birds always work up the tree to the level of the shelf or higher watch to see if the coast is clear, then drop as if to reach the side of the house below, but rising to alight on the shelf. They never come down to the shelf as most birds do. Frequently they eat a little snow from the tree; occasionally they walk out from the base of the tree on the ground. When they drop to a lower part of the tree, they always seem to fall off their perch and flutter, insectlike for a few moments."
The brown creeper is not a shy bird as we meet it during its migration; it doubtless sees few men on its breeding grounds in the northern forests. Clarence M. Arnold (1908) relates the following instance of the bird's disregard of man:
While walking along a wide wood-path I stopped to observe a mixed flock of winter birds in the trees nearby. There were Chickadees, Golden-crowned Kinglets, a Downy Woodpecker and a Brown Creeper, the latter being the first I had seen this season. For this reason, and also because tills species is much rarer than the others, I was watching It closely through my field glass, standing almost motionless in the center of the path; meanwhile, it flew to the base of a chestnut tree about 50 feet from me, and hitched its way up the rough hark. It had reached the lowest branches, about 20 feet from the ground, when suddenly it left the tree and darted straight at me, and, to my amazement, alighted on the left leg of my trousers, just above my shoe, in front, evidently mistaking the black and gray color for the bark of a tree.
Arthur C. Bent (MS.) gives another example of the fearlessness of a bird on her nest. He says: "Hersey and I had been watching a pair of creepers in a pine grove, mixed with a few other trees, partly swampy. Today we found the nest 17 feet up under a loose slab of bark on a large dead white pine. The female bird could not be driven off the nest by rapping the tree or shaking the loose slab; Hersey had to poke her off."
Mrs. A. L. Wheeler (1933) reports the roosting of creepers on the porch of her house. She says: "For the last two winters I have been having some Brown Creepers clinging to the rough stucco in the entrance of our front door. Last winter there were two of them. They came about 4 o'clock, seldom later; they would fly to the bottom, then climb to the top, and 'snuggle' close together in the corner. I put a protection near, to keep the cold wind off them, but they would not come near until I removed it. They paid no attention to persons passing through the door, although they were within easy reach."
One winter afternoon at dusk I saw a creeper settle, evidently for the night, about 6 feet from the ground on the rough bark of a big white-ash tree. A cat was watching the bird and started to climb up toward it. When I drove the cat away, the creeper moved farther up the tree and settled again on the bark.
Some years ago I spent many hours observing the breeding activities of a pair of creepers. I append a quotation from my notes taken at the time (Winsor M. Tyler, 1914)
In watching a pair of Brown Creepers about their nest, whether they are building, incubating their eggs, or feeding their young, one is soon impressed by an air of happiness and calm which pervades the active little birds. From the behavior of many birds, one comes to associate the finding of a nest with anxiety expressed in various ways—with the nervous panic of the Warblers, the Robin's hysterical apprehension, the noisy complaint of the Crow and even with the polite uneasiness of the gentle Field Sparrow. The Brown Creeper, however, although doubtless observant, does not seem to look upon man as a danger; he continues his work uninfluenced, I believe, by close scrutiny. Happy and calm, even under observation, the Creepers appear preoccupied in their work and the comradeship of a pair is very pretty to see. The male shares with the female her interest in the progress of the nest; even although he knows nothing of nest building he collects material and offers it to his mate. Ever ready to assist, he feeds the female while she builds and while she is sitting and, after the young are hatched, he is no less industrious than she In caring for their needs.
Francis Zirrer sends us the following note: "In April 1941, a farmer nearby called my attention to some little brown birds that climb trees coming nightly to a hollow beam, at the end of his barn, that protrudes about 2 yards from the building to within a few feet of several pine trees, part of a considerable grove of pines, into which the farm buildings are set. According to him the birds come every night, enter the opening at the end of the beam, and remain there for the night. With a long pole, and standing on a ladder, I was able to touch the beam, which has such small entrance that it is hardly noticeable from the ground, 25 feet lower. It was quite dark, but upon the touch with the pole, the birds at once began to come out, some flying to the trees nearby, others climbing around the beam or upon the walls of the barn. This, however, was enough, the birds were not molested further. We waited awhile, but it was too dark already, and we could not see whether the birds returned. Next evening, however, we were there earlier, and had the satisfaction to know that the disturbance of the previous night was apparently forgotten; altogether 11 birds entered the beam, but it took quite a while, and much moving in and out, flying back and forth, and climbing around the beam, nearby wall and trees before everybody was settled for the night."
Frederick V. Hebard writes: "This familiar creeper, so common in the Thomasville-Tallahassee region, is absent or extremely rare in southeastern Georgia, except in times of extremely dry weather. Its nearsightedness is nowhere better illustrated than in our tangled branches and river swamps where, instead of dropping to the base of a tree after having reached the top of a nearby one, it drops only to the point where the trunk emerges above the underbrush."
Voice: How seldom we should see the creeper if he did not sound his little note! Yet what a faint little note it is, the shortest, lightest pronunciation of the letters ts. He utters it as he climbs upward over the bark and as he flits downward to the base of the next tree. He often gives also a longer, more characteristic note, which may be suggested by the letters zi-i-i-it, a long, high, ringing note, but not loud, apparently broken into minute syllables so that it has a quavering effect. This note resembles the sound made by a small steel chain which, held by the end and let fall, tinkles into a little heap. A third note, more rarely heard, is a whistle, exquisitely pure, exceedingly high, and, if it were not so tiny, piercingly sharp. It may be given as a single long whistle or in a series of three or four shorter whistles. This note is clearly not a modification of the song, for it is used in the winter months and is not delivered with the cadence of the true song; it is, perhaps, a whistled form of the zi-i-i-it note.
The song of the creeper, heard rarely during migration, but commonly on the bird's nesting grounds, is one of the gems of bird music. Most often a phrase of five notes, a dactyl and a trochee, it is a simple, modest little strain, but it is delivered with such delicacy and daintiness and in a tone so pure and sweet that when he sings we feel we are listening to a delightful bit of verse.
Aretas A. Saunders (MS.) says of it: "The song of the brown creeper is rather rarely heard. I hear it once in several years in the spring migration in April. On the breeding grounds the song evidently continues till the middle of July or later. It is short, weak, and very high-pitched. The pitch varies from the A above the highest note on the piano to the E above that. Most of the songs begin with a rather long note followed by one or two shorter notes that are a third lower in pitch, and these notes are repeated immediately, the six notes constituting the entire song. This may be varied a little by dropping one or two of the short notes or varying the pitch, but a majority of creeper songs are built on this plan."
Frank Bolles (1891) gives a word of praise to the creeper's song. He says: "While watching and admiring these gay survivors of the winter [two butterflies and a moth], we heard a brown creeper sing. It was a rare treat. The song is singularly strong, full of meaning and charm, especially when the size of its tiny performer is remembered."
Field marks: The brown creeper is a tiny bird not much over 5 inches long and nearly half of his length is taken up by his long tail. He is brown on the back, faintly streaked with pale gray, and beneath he is pure white. His beak is long, needle-sharp, and bent downward in a long curve. His wings, rather long for so small a bird, make him appear larger when he opens them in flight.
Enemies: William Brewster (1936) describes the pursuit of a creeper by a northern shrike. He says:
When I first saw him he was in hot pursuit of one of the Brown Creepers and both birds were about over the middle of the river and scarce a yard apart. The Creeper made straight for the big elm which stands at the eastern end of the bridge. When he reached it, the Shrike's bill was within 6 inches of his tall, but he nevertheless escaped, for an instant after the two birds doubled around behind the trunk the Shrike rose to the topmost spray of the elm, where he sat for a minute or more, gazing intently downward, evidently watching for the Creeper. The latter, no doubt, had flattened himself against the bark after the usual practice of his kind when badly frightened and he had the nerve and good sense to remain perfectly still for at least 10 minutes. My eyes were no better than the Shrike's, for it was in vain that I scanned the trunk over and over with the greatest care. Feeling sure, however, that the Creeper was really there, I waited patiently until at the end of the period just named he began running up the trunk, starting at the very point where I had seen him disappear. it was one of the prettiest demonstrations of the effectiveness of protection coloration that I have ever witnessed.
Bradford Torrey (1885) tells thus of the defensive response of a creeper to the scream of a hawk:
It was the last day of my visit, and I had just taken my farewell look at the enchanting prospect from the summit, when I heard the lisp of a brown creeper. This was the first of his kind that I had seen here, and I stopped immediately to watch him, in hopes he would sing. Creeper-like he tried one tree after another in quick succession, till at last, while he was exploring a dead spruce which had toppled half-way to the ground, a hawk screamed loudly overhead. Instantly the little creature flattened himself against the trunk, spreading his wings to their very utmost and ducking his head until, though I had been all the while eying his motions through a glass at the distance of only a few rods, It was almost impossible to believe that yonder tiny brown fleck upon the bark was really a bird and not a lichen. He remained in this posture for perhaps a minute, only putting up his bead two or three times to peer cautiously round.
Fall and winter: The earliest brown creepers that come down into southern New England in fall find the woods almost silent and deserted. The jolly little summer residents have mostly begun their journey southward, and few migrants from the north have arrived thus early: only the vanguard of the blackpoll flight and the earliest juncos. It is sometimes in the first half of September when the first creepers quietly and almost unnoticed appear on their winter quarters, before the trees have dropped their leaves, and when the first frost may be a month away, yet they bring us long in advance the first hint of winter. During their migration, we often see the creepers on the trees bordering the streets of our towns, in our city parks, almost anywhere where there are large trees, but for the winter months they settle in woodlands or in the trees of large estates.
Speaking of the creeper on Mount Mitchell, N. C., Thomas D. Burleigh (1941) says: "Unlike the preceding [red-breasted nuthatch] this species, while it nests in the fir and spruce woods at the top of the mountain, invariably retreats to the valleys in late fall and has never been found above an altitude of approximately 4,500 feet during the winter months."
Mr. and Mrs. Arthur Argue had a very unusual experience on October 31, 1944, at Newburyport, Mass., near the seacoast. Mr. Argue writes: "Walking toward Pine Island [a wooded area in the marsh] we observed 20 brown creepers. The birds were climbing up the sides of buildings, up telephone poles, and fence posts as well as trees. Proceeding to Pine Island we found 30 more creepers. Here they were on trees and rocks and even on the ground. One bird alighted for a moment on my trouser leg."
Range: The greater part of the Northern Hemisphere; in America, from southern Alaska and southern Canada to Nicaragua.
Breeding range: In America the breeding range of the brown creeper extends north to southern Alaska (Tyonek and the Kenai Peninsula); northern British Columbia (Flood Glacier, Nine Mile Mountain, and Hazelton); central Alberta (Glenevis and Camrose); southern Manitoba (Winnipeg); central Ontario (Kapuskasing, Cobalt, and Ottawa); southern Quebec (Rouge River Valley and Grand Greve); and Newfoundland (Stephenville). East to Newfoundland (Stephenville and Makinsons Grove); New Brunswick (Bathurst); Nova Scotia (Advocate); Massachusetts (Essex County and Mount Graylock); and in the mountains south to North Carolina (Grandfather Mountain). South to western North Carolina (Grandfather Mountain); Tennessee (Mount Guyot); northern Michigan (Beaver Islands); Minnesota (St. Paul); eastern Nebraska (Omaha and Lincoln); Wyoming (Wheatland); south through the Rocky Mountains of Colorado (Estes Park and Fort Garland); New Mexico (Taos and Cloudcroft); the highlands of Mexico (Arroyo del Buey, Durango, and Tizayuca, Morelos); Guatemala (Volcán de Fuego and Tecpam); to Nicaragua (San Rafael del Norte); and southern California (Strawberry Valley and Mount Wilson). West to California (Strawberry Valley, Fort Tijon); principally in the mountains of California (Yosemite Valley and Mount Shasta); Oregon (Rogue River Valley and Portland); Washington (Mount Rainier and Bellingham); British Columbia (Queen Charlotte Islands); and Alaska (Tyonek).
Winter range: The winter range extends north to southeastern British Columbia (Comox, Chilliwack, and Okanagan Viilley) ; North Dakota (Grafton and Fargo); Minnesota (Minneapolis); Ontario (Ottawa) ; and Nova Scotia (Pictou). From this line brown creepers are found in winter south through all the States to the Gulf coast, northern Mexico (Chihuahua); and southern California (Victorville and Whittier).
The range as outlined refers to the entire species in America, which is broken up into seven Check-list races with additional races resident in Mexico, Guatemala, and Nicaragua.
The typical race (C. f. familiaris) is confined to the Old World. The eastern brown creeper (C. f. americana) occurs from the eastern edge of the Plains, Manitoba to Nebraska eastward, south to Pennsylvania. The southern creeper (C. f. nigrescens) is the bird of the southern Appalachians from West Virginia to North Carolina and Tennessee. The Rocky Mountain creeper (C. f. montana) occurs from southern Alaska (Cook Inlet), central British Columbia, and in the Rocky Mountains south to Arizona and New Mexico. The Mexican creeper (C. f. albescens) ranges from southern Arizona south to Nayarit and Zacatecas, Mexico. The Sierra creeper (C. f. zelotes) is found in the Cascades and Sierra Nevada from British Columbia and northern Idaho south to the San Jacinto Mountains of California. The Nevada creeper (C. f. leucosticta) is apparently confined to the Charleston and Sheep Ranges of southern Nevada. The California creeper (C. f. occidentalis) is found along the Pacific coast from Sitka, Alaska, to Monterey County, Calif.
Spring migration: L ate dates of spring departure from the winter home are: Florida: Pensacola, March 24. Georgia: Athens, April 1. South Carolina: Spartanburg, April 17. North Carolina-Charlotte, April 17. Virginia: Lynchburg, April 15. District of Columbia: Washington, April 24. Pennsylvania: Pittsburgh, May 8 New York: New York, May 10. Massachusetts: Boston, May 16 Arkansas: Tillar, April 4. Tennessee: Nashville, April 17. Kentucky: Danville. April 22. Missouri: Columbia, April 26. Illinois: Chicago, April 28. Indiana: Indianapolis, April 25. Ohio: Oberlin, May 9. Ontario: Toronto, May 24. Iowa: Sioux City, May 9. Wisconsin: Madison, May 10. Texas: Somerset, April 1. Oklahoma: Oklahoma City, March 18. Kansas: Onaga, April 28. Nebraska: Lincoln, May 8. South Dakota: Mellette, May 6. North Dakota: Fargo, May 7.
Early dates of spring arrival are: New York: Albany, March 16. Massachusetts: Boston, March 16. Vermont: Rutland, March 16. Maine: Ellsworth, March 19. New Brunswick: St. John, April 24. Quebec: Montreal, March 18. Illinois: Chicago, March 18. Indiana: Indianapolis, March 5. Ohio: Painesville, March 12. Michigan: Sault Ste. Marie, April 10. Ontario-Toronto, April 4. Iowa: Sioux City, March 18. Wisconsin: Madison, March 27. Minnesota: Minneapolis, March 28. South Dakota: Yankton. March 18. North Dakota: Fargo, March 29. Wyoming: Wheatland, April 1. Montana: Great Falls, April 28. Manitoba: Winnipeg, April 17. Alberta: Glenevis, April 4.
Fall migration: L ate dates of fall departure are: Alberta: Belvedere, October 22. Manitoba: Aweme, October 22. Wyoming: Wheatland, October 27. North Dakota: Fargo, November 6. South Dakota: Faulkton, November 15. Minnesota: St. Paul, October 22. Wisconsin: Racine, November 4. Michigan: Lansing, November 28. Ontario: Ottawa, October 25. lowa: Keokuk, October 26. Quebec: Quebec, November 23. New Brunswick: St. John, October 8. Maine: Portland, November 6. Vermont: St. Johnsbury, November 17. Massachusetts: Boston, November 20. New York: New York, November 14.
Early dates of fall arrival are: North Dakota: Fargo, September 29. South Dakota: Faulkton, September 18. Nebraska: Hastings, September 28. Kansas: Lawrence, October 1. Oklahoma: Norman, October 17. Texas: Commerce, October 30.
Casual records: A specimen was taken on Mount McKinley, Alaska. October 21, 1907; and there is a single breeding record for extreme southeastern Missouri. In the Bermuda Islands a specimen was taken from a group of three or four seen on November 24. 1870.
Egg dates: California: 33 records, April 16 to July 8; 17 records, May 19 to June 11, indicating the height of the season.
New York: 36 records, May 5 to July 18; 18 records, May 17 to May 26.
Ontario: 12 records, May 23 to June 11.
Washington: 39 records, March 27 to July 15; 20 records, May 5 to May 31.
CERTHIA FAMILIARIS NIGRESCENS Burleigh
In naming and describing this subspecies, Thomas D. Burleigh (1935) says that it is "similar to Certhia familiaris americana, but crown and upper half of back distinctly darker, the prevailing color being fuscous black rather than sepia; primaries darker and approaching clove brown; tail more grayish (hair brown); russet of rump darker; underparts grayer."
He gives the distribution as follows: "Breeds in the Canadian Zone of the southern Appalachians from Pocahontas County, W. Va. (Cranberry Glades), to the Great Smoky Mountains in western North Carolina and eastern Tennessee; winters at a lower altitude in this same region."
Burleigh says further: "This southern race of the brown creeper is easily distinguished in fresh winter plumage by the lack of brown on the crown and the upper half of the back. In worn breeding plumage this character is somewhat obscure, but the color of the tail, hair brown rather than pale brown as in Certhia familiaris americana, is readily diagnostic, as are the darker primaries. Breeding birds taken in June and July are so badly worn that accurate measurements could not be taken, but apparently there is no appreciable difference in size in the two eastern races."
This subspecies is based on the study of 13 specimens taken in the above-mentioned localities.
ROCKY MOUNTAIN CREEPER
CERTHIA FAMILIARIS MONTANA Ridgway
The Rocky Mountain creeper enjoys the widest distribution of any of the western races of the species. The 1931 Check-list states that it "breeds in boreal zones from central Alaska (Mt. McKinley), central British Columbia, and southern Alberta south in the Rocky Mountains to Arizona and New Mexico." Its summer range is at high altitudes in the mountains in the coniferous forests. In New Mexico, according to Mrs. Bailey (1928), it breeds mainly at altitudes ranging from 7,500 to 9,000 feet; after the breeding season the birds were noted as high as 12,000 feet on Pecos Baldy; but it evidently drifts down to much lower levels in fall and winter. Dr. Mearns (1800) found it no lower than 6,500 feet in the Arizona mountains, where he found it "an abundant summer resident of the spruce, fir and aspen woods of high altitude, ranging to the timber line; much less common in the pines, to which it descends, however, in winter, when it is also occasionally seen in the cedars and piñons of the foot-hills, or in the deciduous timber along the streams in the valleys." In Colorado, W. C. Bradbury (1919) found it breeding at an altitude of nearly 11,000 feet, almost up to timberline. Fred M. Packard writes to me from Estes Park, Colo.: "Pairs of these birds are scattered throughout the conifer forests of the park, the principal nesting habitat being in the Canadian and Hudsonian Zones. Between August and early October a number descend into the Transition Zone, some reaching the plains. Their upward migration is in April."
Nesting: The nesting habits, and apparently all other habits of the Rocky Mountain creeper, are similar to those of other races and need not be repeated here. Mr. Bradbury (1919) gives the following measurements of a nest that he found in Colorado: "The extreme dimensions of the nest, including foundation, are: Top to bottom, 7 inches; width, 5 inches. While the nest itself was 3 inches deep and 4 inches broad in one direction, the restrictions due to its location confined it to a breadth of 1½ inches in the other direction. In fact, so limited was the space that the bark itself comprised one side of the cup, the latter being 1½ by 2 inches at the rim and 1½ inches deep."
Eggs: The eggs of this creeper are indistinguishable from those of the other races. The measurements of 20 eggs average 15.9 by 12.3 millimeters; the eggs showing the four extremes measure 17.0 by 12.5, 16.5 by 13.0, 15.2 by 12.2, and 15.5 by 11.1 millimeters.
Winter: Frank L. Farley, of Camrose, Alberta, tells me that numbers of these creepers spend the winter in the spruce woods on the Battle River, south of Camrose. He has never seen them foraging on any trees but spruces, nor has he ever seen them there in summer, and on only one or two occasions as migrants.
CERTHIA FAMILIARIS ALBESCENS Berlepsch
This is a Mexican subspecies that extends its range into the United States for only a short distance into southern Arizona, with one record, probably of a straggler, into extreme southwestern New Mexico.
We found the Mexican creeper fairly common in the pine forests of the Huachuca Mountains, above 8,000 feet and near the summits. The keen ears of my companion, Frank C. Willard, frequently heard the faint wiry notes of the birds, but I could not hear them and they were not easy to see, except when they flew from one tree to another. Numerous dead pines in this region offered attractive nesting sites.
This subspecies differs from the other North American races in being darker above and pale brownish gray below, white only on the chin and throat, and with a chestnut, rather than a tawny, rump.
Nesting: On more than one occasion we spent considerable time following a Mexican creeper about among the dead and living pines near the summit of the Huachuca Mountains, for we knew that eventually the male would call the female off the nest to feed her. Twice the male came near what proved to be the nesting tree, and twice we saw him feed the female; but it was not until the second time that we were able to trace her path back to the nest. She went into a little hole in a big piece of loose bark that hung under a branch, about 35 feet from the ground and near the top of a scraggly dead pine.
The foundation of the nest, which was firmly attached to the bark, consisted of dry pine needles and a few fine twigs; the cup of the nest was well made of fine strips of inner bark and it was profusely lined with feathers. Mr. Willard made the difficult climb to this nest (p1. 17) and secured a set of five fresh eggs on May 15, 1922.
Another set of five eggs was taken, in the same locality on May 30, from a similar nest placed behind a big slab of loose bark on a large dead pine, but only 6 feet above the ground.
Eggs: I have seen as many as six eggs and as few as four in sets of the Mexican creeper. These are similar to the eggs of other creepers, though what few eggs I have seen are of the finely speckled type. The measurements of 26 eggs average 15.3 by 11.8 millimeters; the eggs showing the four extremes measure 16.4 by 11.4, 14.1 by 12.2, 13.9 by 11.4, and 14.7 by 10.9 millimeters.
Young: Referring to the Huachuca Mountains, Swarth (1904b) writes: "About the middle of July young birds began to appear, and they seemed more abundant at this time than at any other. As with many other species breeding in the higher parts of the range, a downward movement began about this time, and though never descending to the foothills, in the late summer Creepers were found scattered all through the upper part of the oak belt. The juveniles seem to be attended by their parents for a long time, for up to the first week in September, when young and old were practically indistinguishable in size and general appearance, the families still clung together, and the old birds were seen continually feeding their offspring."
This creeper seems to be only a summer resident in Arizona.
CERTHIA FAMILIARIS ZELOTES Osgood
Dr. Wilfred H. Osgood (1901) described this form from specimens collected in the southern Cascade Mountains of Oregon and the Sierra Nevada of California, but its range has since been extended northward to southern British Columbia and northern Idaho, and southward to the San Jacinto Mountains of California.
The characters given by the describer are: "Similar to Certhia f. occidentalis but colors more dusky and less rufescent; rump decidedly contrasted with rest of upper parts; similar to Certhia f. montana but much darker; light centers of feathers on head and back much reduced." In this race, the rump and upper tail coverts are between "chestnut" and "hazel," whereas in montana these parts are "cinnamon-rufous." In occidentalis the color of the rump blends into that of the back, while in zelotes and montana the colors of these parts arc sharply contrasted. Dr. Osgood says further: "This subspecies has generally been included under the name occidentalis but it seems to be more similar to montana and its characters might be considered intermediate between those of these two. They are perfectly constant throughout its range, however, so that the form is easily recognizable."
In the Lassen Peak region in summer Grinnell, Dixon, and Linsdale (1930) found the Sierra creeper above 3,300 feet, where it breeds. "The range of situations through which the brown creeper feeds is indicated by the following list of trees, on the trunks or limbs of which individuals were observed: valley oak, live oak, blue oak, digger pine, yellow pine, white fir, incense cedar, lodgepole pine. Deciduous trees predominate within the winter range of the creeper, while coniferous trees predominate in the territory occupied in summer."
In the San Bernardino Mountains, in southern California, Dr. Grinnell (1907) found the Sierra creeper more numerous than he had ever seen it elsewhere. "While observed from an altitude of 5,600 feet in the Santa Ana Canyon to as high as 9,500 feet, above Dry Lake, on the north base of San Gorgonio Peak, yet the creepers were most abundantly represented in the canyons from 6,000 to 7,500 feet. This belt of abundance was also the belt in the Transition Zone where the incense cedar (Libocedrus decurrens) is conspicuously represented."
Nesting: Referring to his experience in the San Bernardinos, Dr. Grinnell (1907) writes:
Although the majority of the nests found were on cedar trunks, one was on a Jeffrey pine, and at least five were on silver firs. In the latter cases the trees were dead and rotting, for it was only on dead trees that the bark had become loosened and separated enough from the trunk to afford the narrow sheltered spaces sought by the creepers for nesting sites. But the huge living cedar trunks furnished the ideal situations. For the bark on these is longitudinally ridged and fibrous, and it frequently becomes split into inner and outer layers, the latter hanging In broad loose strips. The narrow spaces behind these necessitate a very compressed style of nest. A typical nest closely studied by me may be described as follows:
The material employed externally was cedar bark strips one-eighth to one half inch in width. This material had been deposited behind the loosened hark until it packed tightly enough to afford support for the nest proper. The hark strips extended down fully a foot in the cavity, and some of them protruded thru the vertical slit which served the birds as an entrance., The main mass of the nest consisted of shredded weathered, inner bark strips of the willow, felted finest internally, where admixed with a few small down-feathers. This nest proper was (6 inches wide in the direction permitted by the space, and only 1¾ inches across the narrow way. The nest-cavity was 11/3 by 2¼ Inches, so that the sitting parent probably always occupied one position diametrically. * * *
Myself and companions examined fully 30 nests, easily discovered after we once learned how to find them, and of these I should judge the average height to have been 6 feet. In other words the majority could be at least touched by the hand as we stood on the ground. One nest was only 3 feet above ground.
Nests have been reported from other localities in similar situations, behind loose strips of bark on cedars and pines, which are the characteristic nesting sites of the species. Emerson A. Stoner (1938), however, reports a decided departure from the usual rule. He found a nest, in Solano County, Calif., in "the end of a badly decayed laurel stub, 4 feet high and 5 inches in diameter. * * * The nest was open to the sky in the hollow tip of the decayed stub about 6 inches down in the hole, the inside measurement of the cavity being approximately 3 inches in diameter. The nest was of fine, thread-like bark strips, matted with feathers and decaying wood dust. I recognized one of the feathers as that of a Steller Jay, and several were from a Horned Owl. The nesting stub was so badly decayed that it would have snapped off with very little pressure."
Eggs: As a rule, the eggs of all the western subspecies of the brown creeper are similar in number, shape, and coloration to those of the eastern race. Dr. Grinnell (1907) describes two sets of eggs, nine in all, taken in the San Bernardino Mountains, as follows: "The ground-color of the eggs is pure white. The markings are elongated in shape lengthwise of the egg. The brightest markings are burnt sienna, the tint varying from this towards vinaceous as the depth of the markings in the shell substance increases. The darkest markings average 1 millimeter in diameter, while the vinaceous ones vary down to mere points. The markings are most crowded around the large end of the egg-shells, and radiate from this pole in lesser numbers towards the opposite pole."
The measurements of 40 eggs average 15.1 by 11.4 millimeters; the eggs showing the four extremes measure 16.1 by 12.2, 14.7 by 12.2, 14.0 by 10.9, and 15.0 by 10.0 millimeters.
Young: Irene G. Wheelock (1904) writes:
Only 9  days are required to hatch the small eggs, and the naked nestlings squirm and wriggle like so many pink mice in the cosy nest. They are slow in feathering, not being fully covered until 15 days old, and even then the down shows through the feathers in hair-like patches. According to the best of my observations with a powerful field glass, they are fed by regurgitation until 4 days old. After that a visible supply of insect food is given them. Their first journey from home is a creeping about on the bark of the nest tree, to which they cling desperately, aided by their sharp little tails. Instinctively they pick at every crevice in the bark, and soon become so business-like about It that they are quite independent of the adults and of each other.
The plumage changes, food, behavior, and voice of the Sierra creeper are all, apparently, similar to those of the other western subspecies and not very different from those of the eastern race.
Winter: Although permanently resident throughout the year in the Transition Zone of the mountains, the Sierra creeper to some extent wanders down into the foothills and into somewhat different environments in winter. In the Lassen Peak region, Grinnell, Dixon, and Linsdale (1930) found it "present in winter on the western slope down to the lowest altitudes. * * * Although seen usually in rather thick woods, creepers sometimes were found, as at 7 miles east of Red Bluff on December 30, 1927, on the trunks of small, far-separated blue oaks. In winter single creepers were sometimes seen moving along with flocks of feeding bush-tits and kinglets."
John G. Tyler (1913) writes: "The winter of 1910: 11 was remarkable for the number of unusual visitants among our avian friends, that appeared in the vicinity of Fresno. By no means the least interesting of these were the little creepers, which occurred quite numerously in the willow trees that border some of the larger ditches, and doubtless elsewhere as well."
CERTHIA FAMILIARIS OCCIDENTALIS Ridgway
The California creeper occupies the long coastal strip from Sitka, Alaska, to Monterey County, Calif., living in the Canadian and Transition Zones. Whereas the other western races of the brown creeper are mountain birds, during the breeding season at least, this coastal race seems to live and breed at much lower levels, even almost down to sea level. In California it breeds in the great redwood forests, end from there down as far as the Point Lobes Reserve, where Grinnell and Linsdale (1936) found it nesting in the pines. There "a slight preference was shown for the thicker stands of trees, especially where there were old trunks, but this bird followed other species even out among scattered young trees; probably the whole area of pines was covered."
D. E. Brown showed me some of his favorite collecting grounds near South Tacoma, Wash., in which the California creeper was breeding quite commonly, together with several other interesting birds such as Oregon and chestnut-backed chickadees, western golden-crowned kinglets, and Audubon's warblers. It was a large tract of smooth, level, prairielike country that supported a fine open growth of large cedars, two or three species of firs, and a few scattering oaks.
Ridgway (1904) called this the tawny creeper, an appropriate name, also used by others. He says that it is "similar to C. f. zelotes, but browner and more suffused with tawny above; wing-markings more pronouncedly buff; under parts more buffy (about as in C. f. americana)
Nesting: In the locality referred to above, near South Tacoma, Mr. Brown showed me a new nest of the California creeper, which he had found building; it was not over 3 feet from the ground, under a piece of hanging bark on a small, dead oak. This is the locality in which J. H. Bowles tried his interesting and successful experiment of providing artificial nesting sites for these birds. As he (1922) says, he "selected trees with very smooth bark, or else cut the bark down smooth, and nailed against them bark shelters 15 inches or more in length, and 3 or 4 inches in width, leaving a space inside of about 3 inches between the bark and the tree. This inside space will, of course, be tapering towards the bottom, but creepers require a considerable depth for their nests, which are started by a large foundation of twigs, on top of which is built the nestcup of soft bark, feathers, etc."
Prof. Gordon D. Alcorn (MS.) adds the following specifications: "This bark nailed at a convenient height against a vertical tree was furnished with a leaning bark roof and bark floor. With a pocket knife we carved an entrance on each side immediately beneath the roof. The creepers apparently did not care whether the site was natural or not, but they did appear to be rather particular about the entrances. They demanded two. If but one was present, the birds rejected our offering."
Dawson (1923) says that "from a line of, say, 35 or 40 traps he gathers an annual vintage of 5 or 6 sets of creepers' eggs. It is only fair to add that the birds profit in the long run by this arrangement for they are allowed to raise second broods undisturbed throughout an area which offers no other shelter."
Mr. Bowles writes elsewhere (1908)
Nest building commences about the third week in April, either an oak or a fir being selected for the purpose. The Only exception I have ever known to this was one bird that I bad watched until it disappeared under a strip of bark fully 60 feet up in a giant cedar * * *. The nest is placed, as a rule, from 2 to 20 feet above the ground, tho the majority that I have seen were under 10 feet. * * * In its composition the nest has a groundwork of twigs, the size of which depends entirely on the dimensions of the space between the bark and the main trunk of the tree. Sometimes only a scant handful is sufficient, while in one nest the twigs would have filled a quart measure to overflowing. Slender dead fir twigs, from 4 to 8 inches long, are almost invariably used, and this must frequently be a most arduous piece of business. Twigs have to be thrust into the crevice until the first dozen or so lodge firmly, then the rest is easy. In every nest quite a little mound of twigs is found on the ground below, showing how persevering the little architects must have been in the face of repeated failure. Probably they consider such twigs as unsuitable; at any rate it never seems to occur to them to pick up a twig when once it has fallen. Scattered amongst this network of twigs is always a little green moss and a considerable amount of down taken from ferns, willows and cotton-woods. What purpose these serve, beyond ornamentation, must be known only to the birds themselves. On top, and firmly embedded, is the egg cup of the nest, which is composed of a thick felting of fine strips from the inner hark of the cedar, with occasionally a few feathers.
Dawson (1910) tells of a nest that contained, in the cup alone, "cowhair (red and black and white), feathers, horsehair, moss, fine bark, macerated weed-stems, chips, fir needles, bits of white cloth, ravelings, string, cocoons, spider-egg cases, catkins, moth-wings, and vegetable fiber." This was a very unusual collection of material.
S. F. Rathbun sends me the following very good description of a nest of the California creeper, found near Tacoma, Wash., on June 2, 1912: "The base of the nest was entirely of bits of bark and rotten wood, this being merely a mass of material lying at the bottom of the space behind the bark. On this was very uniformly placed dry hemlock and fir twigs, these being of a length that conformed perfectly to the spaces remaining at each side of the nest proper, many of these twigs being bent to accomplish this; generally their ends projected upward with the tips curving somewhat beneath; and among these twigs were many flat, thin pieces of inner fir bark and a little rotten wood. What may be called the nest proper was entirely of plant fibres of a grayish color, finely shredded and very soft, this having the appearance of wool, as it was very elastic; and this material was firmly bound on its inner surface by a few horsehairs. It was not carelessly built in any way, but was neatly and carefully put together and, unlike some others of its kind, substantially built."
Eggs: Creepers' eggs are all about alike and show similar variations. Those of this subspecies are no exception to the rule. The measurements of 40 eggs of this race average 15.5 by 11.9 millimeters; the eggs showing the four extremes measure 16.7 by 12.4, 16.2 by 12.5, 14.0 by 11.2, and 14.6 by 11.1 millimeters.
Food: Professor Beal (1907) writes: "Only seven stomachs of the California creeper were available for examination, but they confirm the good opinion observers have formed of the habits of this bird. Like the titmice and nuthatches, the creeper is an indefatigable forager on the trunks and branches of trees, and the food it obtains there is of the same nature: that is, small beetles (many of them weevils), wasps, ants, bugs, caterpillars, and a few spiders.
"Of the seven stomachs examined, only one contained vegetable food, and this had only 19 percent of seed, too much digested for identification."
Grinnell and Linsdale (1936) saw one "fly out 12 to 15 inches and catch a flying insect."
Winter: All through the winter, California creepers wander about, mostly in pairs or singly, but often associated with the merry little bands of chickadees, titmice, nuthatches, and kinglets. But they always seem absorbed in their own affairs, diligently searching for their food on the tree trunks; their association with other species is probably due to a community of interest rather than to a desire for company, for creepers are not especially sociable.
CERTHIA FAMILIARIS LEUCOSTICTA van Rossem
In naming and describing this local race, Mr. van Rossem (1931) says: "Among the North American races of Certhia familiaris this is the palest and grayest. Dorsally the coloration resembles, in the absence of brown tones, Certhia familiaris albescens Berlepsch, but is much paler and the streaks are. pure white instead of pale gray. Ventrally leucosticta is clear pure white, tinged on the flanks with pale gray and on the under tail coverts with pale clay color.
Van Rossem gives the range as "Transition and Alpine Zones in the Sheep and Charleston Mountains, Clark County, Nevada."
"The five specimens," he says, "on which the new form is based are uniform in characters and bear little resemblance to Certhia familiaris zelotes Osgood of the Sierra Nevada, or to Certhia familiaris montana Ridgway of the Rocky Mountains, with good series of both of which races they have been compared. In the relative amount of white on the dorsal surface there is close agreement between leucosticta and montana, but while in montana light brown tones prevail, leucosticta is ashy and practically colorless dorsally except on the rump."
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