Part 14

They say further: “Two of the nest cavities we found were in such unusual sites as to call forth comment. One at Hazel Green was in a slanting upright limb on a prostrate dead black oak trunk lying in a grassy meadow, fully 150 feet from the margin of the forest. The hole was excavated on the lower side of the stub. The other nest was at Tamarack Flat, in the butt end of an old log, lifted above the ground when the tree fell over a granite outcrop. This hole was about 7½ feet above the ground, and as with the other there were piles of chips immediately beneath it.”

Grinnell, Dixon, and Linsdale (1930) mention a nest they found in the Lassen Peak region that was “four meters up in the trunk of a dead-topped aspen.” Bendire (1895) mentions a nest found near Camp Harney, Oreg., that was about 25 feet from the ground in a dead limb of a pine; this nest seems to be at about the limit as to height above ground. A set in my collection was taken from a nest 10 feet up in a dead aspen.

_Eggs._--The white-headed woodpecker lays three to seven eggs, four being the commonest number, and five rather often. These vary in shape from ovate to short-ovate. They are pure white and moderately or quite glossy. Grinnell and Storer (1924) say: “The eggs in one set had a wrinkled appearance at the smaller end as though that end had been compressed before the shells had hardened. Eggs which are advanced in incubation are apt to be soiled by pitch; this is doubtless brought in by the parent birds on their bills, feet, or plumage.” Sometimes the eggs show tiny black dots, or are profusely smeared with black from the same cause. The measurements of 50 eggs average 24.26 by 18.11 millimeters; the eggs showing the four extremes measure =26.40= by 18.29, 25.40 by =19.50=, =21.84= by 17.78, and 22.86 by =16.76= millimeters.

_Young._--Incubation is said to last for 14 days and to be shared by both sexes. Both parents also assist in the care and feeding of the young. Clarence F. Smith tells me that “the female at one nest made trips about twice as frequently as the male; her visits were about two minutes apart, while the visits of the male were about five minutes.” Grinnell, Dixon, and Linsdale (1930) write:

On July 1, the young woodpeckers, by this time half-grown, were being fed by the parents, mostly by the female. Food was brought at intervals averaging fifteen minutes each. The birds foraged at distances up to a quarter of a mile away from the nest. The female carried away the feces.

On July 11 the female seemed to be coaxing the young from this nest. When the young woodpeckers stuck their heads out of the cavity, the parent would move away from the entrance and call, although it remained on the tree trunk. When a person shook the stub two of the young birds flew out and went thirty meters before coming to the ground. When placed on a tree trunk the birds could move freely upward or downward. Within a few minutes one of the young birds could fly so well that it successfully evaded capture by the observer.

_Plumages._--As with other woodpeckers, the young are hatched naked and blind, but the juvenal plumage is acquired before the young bird leaves the nest. The juvenal plumage is much like that of the adult but duller, and the bill is shorter and weaker; the contour plumage is softer and looser; the lower parts are brownish black instead of clear black, and the back is only a little darker; the white in the primaries is more restricted. In the young male, the posterior half of the crown is largely “vermilion” or “salmon orange”; these reddish colors are much reduced or entirely absent in the young female. Ridgway (1914) says that the feathers of the hind neck and underparts are sometimes, perhaps on younger birds than I have seen, “indistinctly and narrowly margined at tip with grayish, and the hindneck sometimes indistinctly spotted with whitish.” By the middle of September this juvenal plumage, including the wings and tail, has been replaced by the first winter plumage, which is like that of the adult, except for somewhat less white in the primaries. Adults have a complete annual molt, which begins in July and is generally completed before the end of September.

_Food._--The white-headed woodpecker forages for its food mainly, if not entirely, on the trunks and branches of coniferous trees, living or dead. Mr. Skinner writes to me that he has seen it feeding on the trunks of sequoias, sugar pines, and Douglas firs, searching most diligently and thoroughly in the crevices in the bark for insects and their eggs; it generally begins low down on the tree and progresses upward, working pretty well up to the top of the tree before flying off; occasionally, one has worked horizontally around a tree trunk, but not downward. Dr. J. C. Merrill (1888) describes its method of feeding very well, as follows:

So far as I have observed, and during the winter I watched it carefully, its principal supply of food is obtained in the bark, most of the pines having a very rough bark, scaly and deeply fissured. The bird uses its bill as a crowbar rather than as a hammer or chisel, _prying_ off the successive scales and layers of bark in a very characteristic way. This explains the fact of its being such a quiet worker, and as would be expected it is most often seen near the base of the tree where the bark is thickest and roughest.

It must destroy immense numbers of Scolytidae, whose larvae tunnel the bark so extensively, and of other insects that crawl beneath the scales of bark for shelter during winter. I have several times imitated the work of this bird by prying off the successive layers of bark, and have been astonished at the great numbers of insects, and especially of spiders, so exposed.

Prof. F. E. L. Beal (1911) examined only 14 stomachs, but says that “half of the animal food of the white-headed woodpecker (_Xenopicus albolarvatus_) is ants, but the most pronounced characteristic of this bird is its fondness for the seeds of pines, which constitute more than half of the food.”

Grinnell and Storer (1924) say: “Stomachs of two adult birds, obtained at Merced Grove Big Trees on June 10, 1915, and at East Fork of Indian Cañon, June 24, 1915, both held ants, some of which were large carpenter ants. The stomach of one of the young birds from the nest mentioned above contained remains of 2 large spiders, a large ant, 2 boring beetles, and a whole fly larva.”

Major Bendire (1895) quotes Rollo H. Beck as saying: “I noticed one of these birds on some fallen logs near the road, busily engaged in catching spiders, searching for grubs, and frequently flying after passing insects, catching them in mid-air in the manner of the California Woodpecker.”

_Behavior._--Dr. Merrill (1888) writes: “Though not shy, and with care generally approachable to within a short distance, it is watchful and suspicious, and seems to know very well what is going on even if it does not see fit to fly away, though it is more apt to do this than to dodge around the trunk. The flight is direct, and rather slow and heavy.” Dr. Merrill noted that the skull of the white-headed woodpecker is “noticeably less hard and dense” than the skulls of other woodpeckers; this is probably due to the fact that its method of feeding requires less heavy drilling into hard wood.

Mrs. Florence M. Bailey (1902) says: “_Xenopicus_ works with apparent indifference on trunks or branches. Like the Nuttall woodpecker he often lights upside down. In hunting over the bark he easily backs down the trunk, or if he takes the notion will fly, or perhaps drop backwards, a foot or so. He will also light sidewise on a branch and grasp the limb with his tail as if afraid of falling off. It is interesting to see him explore cracks in the bark. Standing on the edge he pokes his head into the dark cavern, turning it from one side to the other inquiringly.”

Grinnell and Storer (1924) write:

At Tamarack Flat, on May 26, 1919, a female white-headed woodpecker was seen to flush from her nest about ten feet above ground in a dead pine stub. Tapping by one of us on a nearby hole had caused her to leave, but she returned to the vicinity almost immediately. Then, for fully 25 minutes, while the observer remained within watching distance the bird foraged, preened, and flew about from one to another of the circle of 8 or 10 trees within a 50-foot radius of the nest, but always kept the nest tree in her sight. About every 5 minutes she would fly to the nest. In approaching it, she would swoop below its level and then glide up to the site with decreasing speed so as to end her flight with little or no momentum. Then, having gained claw-hold, she would poke the fore part of her body into the hole, withdraw it at once and repeat this performance four or five times before flying away again. Finally, after fully half an hour had elapsed, and her suspicions had been allayed, she went in, to remain. During this entire time the male kept out of sight and was heard only twice.

Van Rossem and Pierce (1915) noted its manner of drinking, thus: “White-headed woodpeckers were often observed to drink at a small stream near our camp at Bear Lake, where a pine sapling grew from the edge of a small pool. On this sapling the birds would alight, usually about three feet from the base, ‘hitch’ quickly backwards down the trunk to the water, and, leaning sharply to one side, drink by quick, nervous dips.”

Another method of drinking is described by Grinnell, Dixon, and Linsdale (1930), as follows: “In mid-afternoon one flew down from a yellow pine to some shallow, running water in an open roadside near Mineral. It alighted in a horizontal position on the ground and dipped its bill into the water six times. After each dip the bird raised its bill skyward at an angle of fully eighty degrees from the horizontal. After drinking, the bird flew to a prostrate log, and foraged horizontally along its lower curvature.”

Some observers seem to think that the white-headed woodpecker rarely, if ever, drums on tree trunks, but seeks its food more quietly; but Alexander Sprunt, Jr., tells me that the birds he saw in Oregon “drummed and beat upon the tree trunks and telephone poles at the roadside, exactly as any other woodpecker.” Clarence F. Smith writes to me that “one male bird was a regular overnight guest, hanging to the ridgepole of our cabin, outside the wall, just beneath the eaves. He never made any attempt to drill the wood there.”

_Voice._--Grinnell and Storer (1924) say that “the usual call note of this woodpecker is a single _wiek_, but when excited, the female calls _cheep-eep-eep-eep_, very fast, and repeats the call every few seconds. The male, under similar circumstances calls _yip, yip, yip, yip_, in a much shriller tone, but in slower time.” Mr. Dawson (1923) once heard “a double or treble call-note, _chick-up_ or _chick-it-up_, which reminded me somewhat of the Cabanis’s cry.” Major Bendire (1895) heard it utter “a sharp, clear _witt-witt_” as it passed from one tree to another; he considered it a rather silent bird.

_Field marks._--The white-headed woodpecker could hardly be mistaken for any other bird. It is the only woodpecker with a wholly black body and a wholly white head; while perched it shows a long white stripe in the wing, and while flying a large white patch in the wing is conspicuous; the narrow red band on the nape is not conspicuous and can be seen only at short range and only in the adult male; young birds show more or less red in the crown. One would think that such a strikingly marked bird would be very conspicuous, but such is not the case; its coloration is, in fact, somewhat concealing in its chosen environment; its quiet behavior helps to make it less obvious. For example, Dr. Merrill (1888) writes: “On most of the pines in this vicinity there are many short stubs of small broken branches projecting an inch or two from the main trunk. When the sun is shining these projections are lighted up in such a manner as to appear quite white at a little distance, and they often cast a shadow exactly resembling the black body of the bird. In winter when a little snow has lodged on these stubs the resemblance is even greater, and almost daily I was misled by this deceptive appearance, either mistaking the stub for a bird or the reverse.”

Furthermore, Grinnell, Dixon, and Linsdale (1930) state that “it was further observed that in usual pose, either when foraging or when in digging or inspecting a nest hole, the whole back of a bird (either sex) appeared to a nearby observer solidly black, clear to the top of the head. The white showed only as a very narrow rim or border anteriorly around the black of the head. * * * At the same time the concealing black of the bird’s dorsal surface must cover all of the area of the bird exposed to the view of the potentially inimical observer at more or less distance.”

And again, Mrs. Bailey (1902) says:

Impossible as it would seem at first sight, I have found that the snow-white head often serves the bird as a disguise. It is the disguise of color pattern, for the black body seen against a tree trunk becomes one of the black streaks or shadows of the bark, and the white head is cut off as a detached white spot without bird-like suggestions. On the other hand, when the bird is exploring the light-barked young Shasta firs or gray, barkless tracts of old trees, the white of the head tones in with the gray and is lost, the headless back again becoming only a shadow or scar. But the most surprising thing of all is to see the sun streaming full on the white head and find that the bird form is lost. The white in this case is so glaring that it fills the eye and carries it over to the light streaks on the bark, making the black sink away as insignificant.

The activities of this and other woodpeckers play an important role in the welfare of the forests and the lives of the little furred and feathered denizens of the woods. It is a well-known fact that woodpeckers are most useful in guarding the living trees and destroying the insect pests that injure them; but Grinnell and Storer (1924) have called our attention to the fact that woodpeckers in general, and the white-headed woodpecker in particular, contribute, by their excessive drilling of nest holes, “rather directly toward bringing down the standing dead timber.” They continue:

Drilling by woodpeckers results in an increase in the number of entrances through which insects may get at the heart wood of a tree and thus hasten its ultimate disintegration. Water, also, is thus afforded an easier entrance and this hastens decay. Eventually each and every tree must yield its place in the forest to seedlings. The woodpeckers hasten this process of replacement, once the tree is dead.

Many of the wood-inhabiting animals depend upon this woodpecker to furnish them convenient nest holes or retreats. We have found mountain chickadees and slender-billed nuthatches incubating their own eggs in holes drilled in earlier years by the white-headed woodpecker; a Sierra flying squirrel was found occupying an old white-head’s hole. Probably, tree-dwelling chipmunks and perhaps California pigmy owls also occupy holes of this woodpecker.

DISTRIBUTION

_Range._--Pacific coast of the United States; occurring rarely in southern British Columbia; nonmigratory.

The range of the white-headed woodpecker extends =north= to Washington (Methow River and probably Fort Colville); and northern Idaho (Fort Sherman). =East= to western Idaho (Fort Sherman and Grangeville); eastern Oregon (Hurricane Creek, Powder River Mountains, Anthony, and Camp Harney); western Nevada (Carson); and eastern California (Bijou, Yosemite Valley, Pyramid Peak, San Bernardino Mountains, and Cuyamaca Mountains). =South= to southern California (Cuyamaca Mountains and Mount Pinos). =West= to the western slopes of the Sierra Nevadas, Calif. (Mount Pinos, Bear Valley, Fyffe, Butte Lake, and Mount Shasta); western Oregon (Pinehurst, Foley Creek, and The Dalles); and western Washington (Kalama, Cle Elum, and Methow River).

The species has been separated into two subspecies, the northern white-headed woodpecker (_Dryobates a. albolarvatus_), occupying most of the range south to the southern end of the Sierra Nevadas, and the southern white-headed woodpecker (_D. a. gravirostris_), found in the mountain ranges of southern California.

_Casual records._--A specimen collected near Point Bonita, Marin County, Calif., on July 20, 1932, is the only coastal record in that State. There is, however, an old record for Grays Harbor, Wash. (previous to 1892), which cannot now be confirmed.

In the Provincial Museum at Victoria, British Columbia, there is an unlabeled specimen said to have been collected in the Similkameen Valley. Two have been collected at Okanagan, British Columbia, one on December 20, 1911, and the other on January 24, 1914.

_Egg dates._--California: 53 records, April 24 to June 16; 27 records, May 22 to June 7, indicating the height of the season.

DRYOBATES ALBOLARVATUS GRAVIROSTRIS (Grinnell)

SOUTHERN WHITE-HEADED WOODPECKER

HABITS

Dr. Joseph Grinnell (1902), in describing and naming the white-headed woodpecker of the mountain ranges of southern California, gave as its characters: “Similar to _Xenopicus albolarvatus_ but bill much heavier, and size in general slightly greater.” He named it as a distinct species, on the theory that “the material at hand does not justify subspecific treatment of these two forms. Geographical continuity of ranges possibly exists; but it seems quite as likely that there is a broad hiatus in the vicinity of Tehachapi Pass, whence I can find no record of the white-headed woodpecker.”

The range of this form includes the San Gabriel, San Bernardino, San Jacinto, Santa Rosa, and Cuyamaca Mountains in southern California. Dr. Grinnell (1908) found this woodpecker rather scarce in the San Bernardino Mountains, and says: “They were seen only in the Transition zone, none being observed above the fir belt, and but very few down into pure yellow pine tracts. In the vicinity of Fish creek, 6,500 feet, a few pairs were breeding in June. On July 5, 1905, I found a nesting hole seven feet up in a dead pine stub, which contained four half-fledged young. We did not see the species anywhere higher than 8,000 feet, except on the south slope of Sugarloaf, where on July 11, 1906, one was seen among the silver firs at about 9,000 feet altitude. About Bluff lake they were more common than anywhere else, and a few were seen on the northern slopes of Sugarloaf at about 8,000 feet, in August.”

W. L. Dawson (1923) writes: “In the San Jacinto Mountains, where these white-heads outnumber all other woodpeckers combined, our attention was drawn, on the 6th day of June, by a male who tittered anxiously as we stumbled along the rough trail. We camped on the prospect immediately, but it took a full hour to trace the ‘damage’ to a hole fifty feet up in a yellow pine stub, which was three feet through at the base. * * *

“We found a clean-cut round hole, one and a half inches in diameter, which gave admission to a cavity ten inches deep, and which had for its outer wall only the thick bark of the tree.”

Frank Stephens wrote to Major Bendire (1895): “_Xenopicus albolarvatus_ is a resident of the pine regions of southern California, but is not common excepting possibly in a few localities. I have never observed it below the pines. I have taken incubating birds in June in the Cuyamaca Mountains at altitudes of about 7,000 feet. The nesting sites here were in very large dead pine trees and inaccessible.”

This woodpecker seems to show a tendency to nest, at least occasionally, at greater heights above ground than its northern relative, but otherwise its habits seem to be very similar.

The eggs are similar to those of the northern race. The measurements of 20 eggs average 24.67 by 18.60 millimeters; the eggs showing the four extremes measure =26.70= by 19.50, 25.60 by =19.70=, and =22.62= by =16.67= millimeters.

PICOÏDES ARCTICUS (Swainson)

ARCTIC THREE-TOED WOODPECKER

PLATES 15, 16

HABITS

Although not found in the strictly Arctic, treeless regions, this bird is probably well named, for its range as a whole averages farther north than that of any other woodpecker except _P. tridactylus_. It is a bird of the boreal forests of spruces and firs, ranging as far north in Alaska and northern Canada as these trees grow, and extending its range southward throughout the Canadian Zone into the Northern United States and farther southward in some of the higher mountain ranges.

In the eastern portion of its range this woodpecker seems to prefer the dense virgin forests of spruces and balsam fir, but it nests mainly in the more open windfalls or burned-over clearings where there are plenty of dead, standing trees in which to excavate its nest. In New York State, near the southern limit of its breeding range, a typical locality is thus described by Laurence Achilles (1906): “At three thousand feet or more above the sea, in the denser spruce and balsam forests of the Adirondacks, the Arctic three-toed woodpecker is fairly common. * * *

“The trees near the nest were chiefly spruces, with a few balsams and birches scattered among them. The birds had selected a rather open place for their nesting-site, as, within a radius of ten yards from their nest, there were several windfalls and dead spruces. The ground was carpeted with moss, while linnea, clintonia, wood-sorrel and bunchberry were blossoming in profusion near the base of the tree.”

In the Midwestern States and Provinces, the Arctic three-toed shows a decided preference for tamarack swamps, especially where these have been burned over, leaving a few dead or dying trees still standing; these trees not only furnish an abundant food supply but offer many convenient nesting sites. Into such attractive habitats these birds sometimes congregate to form small breeding colonies.

The Weydemeyers (1928) say that in northwestern Montana this woodpecker “is found most frequently in Transition zone woods that have been logged or burned over. In virgin forests it occurs sparingly in yellow pine woods at low elevations; more commonly in mixed broad-leaf and conifer, and Douglas fir, associations; and rarely in alpine fir and lodgepole pine woods of the higher mountains, in the Canadian zone. Its favorite feeding trees are Douglas fir and western larch.”

_Nesting._--Philipp and Bowdish (1919) found four or five nests of the Arctic three-toed woodpecker in Northumberland County, New Brunswick, in May and June 1917. Most of the nests were in living balsam firs with dead hearts, but one was “in a dead maple stub, near the edge of a large burnt barren, and a short distance from the edge of mixed woods.” This was “at a height of about ten feet. The cavity measured 10½ inches from the lower edge of entrance to bottom. The entrance measured 1⅝ inches in height and 1¾ inches in width.” They say that--