WILLIAMSON’S SAPSUCKER

HABITS

Williamson’s sapsucker is not only one of our most unique woodpeckers in its striking coloration, but it has an interesting history. Owing to the radical difference in appearance between the two sexes, they were for some time regarded as two distinct species. The female was the first to be described by John Cassin (1852, p. 349), based on a specimen collected by John G. Bell in Eldorado County, Calif. Under the name black-breasted woodpecker (Melanerpes thyroideus), Cassin describes and figures (1854) the adult female as the male of the species and says of the female: “Similar to the male, but with the colors more obscure, and the black of the breast of less extent and not so deep in shade,” which is a very fair description of the immature female. The male was discovered and described and figured by Dr. Newberry (1857, p. 89, pl. 34) under the name Picus williamsonii, based on a specimen collected by him on August 23, 1855, on the shores of Klamath Lake, Oreg. Baird, Cassin, and Lawrence (1860) give a very good description of an adult male, as the male of the species, but say “female with the chin white instead of red,” which, of course, is the immature male. Thus we have the adult of each sex regarded as the male of a species, and the young bird of each sex regarded as the female of a species. With careless, or improper, sexing of specimens, such an error might easily occur, but it is remarkable that it remained so long undiscovered. Baird, Cassin, and Lawrence (1860) describe the male as Sphyrapicus williamsonii Baird, Williamson’s woodpecker, and the female as Sphyrapicus thyroideus Baird, brown-headed woodpecker. J. G. Cooper (1870), in the Geological Survey of California, edited by Baird, follows the same error but calls the female the round-headed woodpecker. Even Baird, Brewer, and Ridgway, in their history of North American Birds, had not discovered the error, for they use substantially the same nomenclature.

It remained for Henry W. Henshaw (1875) to discover the true relationship of the two supposed species and clear up the previous misunderstanding. He writes: “While near Fort Garland, I obtained abundant proof of the specific identity of the two birds in question; williamsonii being the male of thyroideus. Though led to suspect this, from finding the two birds in suspicious proximity, it was some time before I could procure a pair actually mated. A nest was at length discovered, excavated in the trunk of a live aspen, and both the parent birds were secured as they flew from the hole, having just entered with food for the newly hatched young.”

Mr. Ridgway (1877) comments on the discovery as follows:

A suspicion that the two might eventually prove to be different plumages of one species several times arose in our mind during the course of our field-work, the chief occasion for which was the very suggestive circumstance that both were invariably found in the same woods, and had identical manners and notes, while they also agreed strictly in all the details of form and proportions, as well as in the bright gamboge-yellow color of the belly. Our theory that thyroideus was perhaps the young, and williamsoni the adult, proved erroneous, however; and it never occurred to us that the differences might be sexual, an oversight caused chiefly by the circumstance of our having seen in collections many specimens of thyroideus with a red streak on the throat and marked as males, while the type specimen of williamsoni had a white streak on the throat and was said to be a female. We were thus entirely misled by the erroneous identification of the sex in these specimens. We gave the matter up, however, only after shooting a very young specimen of what was undoubtedly williamsoni, and another of thyroideus, both of which very closely resembled the adults of the same forms, a circumstance which at once convinced us that the differences could not depend on age; so we finally concluded that the two must be distinct.

All observers seem to agree that this woodpecker is confined to the higher elevations in the mountains among the pines, in sharp contrast to the haunts of the red-breasted sapsucker at lower levels among the deciduous trees.

Joseph Grinnell (1908), referring to the San Bernardino Mountains, in southern California, says: “This Williamson sapsucker appeared to be restricted to the Canadian zone and upper edge of Transition. We found it only among the tamarack pines on the slopes and ridges of San Gorgonio peak, and among the silver firs, tamarack and yellow pines around Bluff lake. In the former locality the species was common for a woodpecker, especially around Dry Lake, 9,000 feet altitude, where several nests were found.”

Courtship.—Charles W. Michael (1935) noted the mating behavior of a male Williamson’s sapsucker, which had just left a fresh nest-hole, as follows:

He sounded his harsh call several times. Seemingly in answer to his call the female appeared. This was the first we had seen of the female. The female examined the nest hole, flew up on a branch and uttered a series of low notes. The male joined her, alighting a foot away and uttering a series of low chuckling notes. While giving these notes he strutted along the limb with wing-tips and tail jerking rapidly. As he approached his mate she crouched low on the limb and the mating act was accomplished. The act lasted several seconds before the birds separated to perch side by side on a limb. After a minute or so the female flew off through the woods and the male went into the nest hole. In about five minutes the female came to the nest hole and again uttered her soft coaxing notes. The male came out of the hole and both birds flew to a limb where again the mating act was consummated. The male returned to the nest. In our two-hour watch the female only went to the nest hole to call the mate out.

Nesting.—Dr. Grinnell (1908) says of its nesting in the San Bernardino Mountains:

Tamarack pines were selected as nest trees, usually old ones with the core dead and rotten but with a live shell on the outside. In one found June 22, 1905, there were four holes drilled one above the other about eighteen inches apart, and one of these holes contained three small young and two infertile eggs. * * * Later on in the same day another nest was found similarly located containing four half-fledged young. A nest with half-grown young was found in the same locality, June 14, 1906; and on June 26 of the same year a nest twenty feet up in a half-dead tamarack held five two-thirds-grown young and one rotten egg. So that a full set of eggs probably varies from four to six in number. On June 18, 1907, a nest with small young was located ten feet up in an exceptionally large nearly dead tamarack pine. This was one of the lowest of a series of forty-seven well-formed holes of similar external appearance, which penetrated this one tree trunk on all sides up to an estimated height of thirty-five feet.

W. L. Dawson (1923) writes: “One soon comes to recognize the rigid requirements of the Williamson Sapsucker in the matter of nesting sites. Given a pine which is beginning to die at the top, usually in a fairly sheltered situation, and a pair of birds will adopt it for a permanent home. They will occupy it from year to year, or perhaps the year around, nesting twice in a season; and a long occupation is evinced by a trunk riddled with holes at all levels. One such ‘family tree,’ closely examined, had 38 holes, apparently complete and fit for habitation or incubation. At the time of our visit, on June 19th, the male was industriously drilling a new excavation at a height of 45 feet.”

Major Bendire (1895) says:

I obtained my first set of eggs of this species on June 3, 1883, about 9 miles north of Fort Klamath, in the open pine forest on the road to Crater Lake. It consisted of five eggs, slightly incubated. The nesting site was excavated in a partly decayed pine whose entire top for some 20 feet was dead; the height of the excavation from the ground was about 50 feet. The man climbing the tree reported it to be about 8 inches deep and about 5 inches wide at the bottom, and freshly made. A second set, of six fresh eggs, was taken June 12 of the same year, about 12 miles north of the Post, at a still higher altitude than the first one. It came also out of a pine about 40 feet from the ground. A third nest, found a week later, near the same place, contained five young, just hatched. This nest was in a dead aspen, about 20 feet from the ground. Only one brood is raised, and, like the other two species, it is only a summer resident in the vicinity of Fort Klamath.

Other observers have found nests in lodgepole pines, red firs, and larches at various heights from 5 to 60 feet above ground but always in conifer associations.

Eggs.—Bendire (1895) says: “The number of eggs laid to a set varies from three to seven, sets of five or six being most often found. These, like all woodpecker’s eggs, are pure china-white in color; the shell is close grained, rather thin, and only slightly glossy. In shape they vary from ovate to elongate ovate, and a few approach an ovate pyriform, a shape apparently not found in the eggs of other species of this genus.” The measurements of 30 eggs average 23.54 by 17.23 millimeters; the eggs showing the four extremes measure 25.91 by 17.27, 24.1 by 18.3, and 20.1 by 15.4 millimeters.

Young.—Both parents assist in the duties of incubation, but the length of time required for this function does not seem to be definitely known; both sexes also help in feeding the young. Dr. J. C. Merrill (1888) says, of two nests that he watched for some time: “The males brought food about twice as often as did the females, and frequently removed the excrement of the young on leaving the nest, alighting on the nearest tree for a moment to drop it and to clean their bills; I did not see either of the females remove any excreta. About four feet above one of the holes was another occupied by a pair of pigmy nuthatches, but neither species paid any attention to the other when they happened to arrive with food at the same time.”

Dr. Grinnell (1908) writes: “We usually located the nests by watching the movements of the parent birds, which flew from their foraging places, often far distant, direct to the nest tree. The young uttered a whinnying chorus of cries when fed, and the adults, though generally very quiet, had a not loud explosive cry, more like the distant squall of a red-tailed hawk. The bill and throat of an adult male, shot as it was approaching a nest, was crammed with large wood ants, not the kind, however, that are common at lower altitudes and smell so foully.”

Charles W. Michael (1935) watched a nest containing young, in the Yosemite region, of which he says:

When we arrived, about ten o’clock, both parent birds were bringing food. We watched the birds for an hour and a half and in this period of time the male made nine trips to the nest hole and the female made seven trips. The young were small, as the parent birds went completely into the nest hole. The birds, male and female, always came onto the tree trunk above the nest hole and hitched jerkily downward until on a level with the hole. They landed anywhere between five and fifteen feet above the hole; the female was likely to land nearest to the hole. * * * About every other trip excrement was carried from the nest. When the male cleaned nest he carried the feces away and dropped them some distance from the nest. When the female cleaned nest she came to the entrance from within, looked about and then dropped the refuse before leaving the nest hole.

Plumages.—The most remarkable characteristic of this woodpecker is the striking difference in the plumages of the two sexes at all ages, from the first plumage of the young bird to its maturity; in most birds the sexes are much alike in the juvenal plumage; but the young male Williamson’s sapsucker is much like the adult male, and the young female is much like the adult female; the principal character common to both sexes at all ages is the white rump.

These young sapsuckers are fully fledged before they leave the nest.

The young male, in juvenal plumage in summer, differs from the adult male in having a smaller and weaker bill and softer, more blended plumage; the black areas, except the wings and tail, which are like those of the adult, are dull brownish black, instead of clear glossy black; there are usually numerous elongated white spots or streaks, more or less concealed, on the scapulars and upper back, and often a few small whitish spots on the crown; the chin and upper throat are white, instead of scarlet; the center of the breast and abdomen is dull yellowish white, instead of bright “lemon-chrome”; the sides and flanks are barred, instead of striped or spotted, with dusky.

The young female differs from the adult female in having a smaller and weaker bill and softer plumage; the black breast patch is entirely lacking; the breast, sides, and flanks are barred with dusky, but less distinctly than in the adult; and the yellow of the central breast and abdomen is much paler.

These two juvenal plumages are worn for only a short time in summer. I have seen young males molting into their first winter plumage, which is practically adult, as early as August 9; and young females begin to show the increasing black breast patch as early as August 6; but this molt is slow, or variable, and is sometimes not completed until November or December.

Adults apparently have their complete annual molt mainly in August and September.

Food.—Mrs. Florence M. Bailey (1928) says: “In 17 stomachs examined, 87 percent was animal matter and 13 percent vegetable. Of the animal contents, 86 percent was ants, and cambium made up 12.55 percent of the total food.”

Grinnell and Storer (1924) write:

In the Yosemite region the Williamson Sapsucker is closely associated with the lodgepole pine. While this tree seems to furnish the bird’s preferred source of forage, practically all other species of trees within its local range are also utilized. We saw workings attributable to this sapsucker on the alpine hemlock, red and white firs, Jeffrey pine, and quaking aspen.

The amount of work which this sapsucker will do upon a single tree was impressed upon us while we were at Porcupine Flat in early July, 1915. In that locality there was a lodgepole pine (Pinus murrayana) about 60 feet high, which showed no marks of sapsucker work previous to the current year. The tree was in full leafy vigor and measured 8 feet 3¼ inches in girth at 3 feet above the ground. There were numerous live branches down to within 6 feet of the ground. Twenty-six irregularly horizontal rows of fresh punctures were counted on one side of the trunk, the lowest being only 18½ inches above the ground, and the highest about 40 feet. * * *

During the winter months when sap is practically at a standstill in the coniferous trees at high altitudes, the Williamson Sapsucker must needs seek other fare. A few of our own observations added to those of other naturalists suggest that during the winter season the birds may forage in a large part on dormant insects or on insect larvae hidden in crevices in the bark. If such is the case, whatever the damage done by these birds to the forest as a whole during the summer months, it is partially offset by their wintertime activity. In any event, the attacks of the Williamson Sapsucker on the lodgepole pines of the central Sierra Nevada cannot be considered as of great economic importance, for these trees are there used little if at all for lumber or for any other commercial purpose.

Behavior.—Dr. J. C. Merrill (1888), at Fort Klamath, Oreg., found this sapsucker “shy and very suspicious. A noticeable habit here is the frequency with which it works down as well as up a trunk, and when one dodges around a tree, in which, by the way, it is unpleasantly expert, it is as apt to reappear twenty feet below where it was last seen, as above. In searching for food it will often work up and down a favorite tree repeatedly. In all its movements it is quick and active, and gives one the impression of being thoroughly wide awake, which impression the would-be collector is speedily convinced is correct.”

Voice.—Mr. Michael (1935) says: “When the sapsuckers met at the nest site they exchanged greetings in a ‘rubber doll’ tone of voice. The nasal quaver of notes was remindful of a call often sounded by the red-breasted sapsucker. Another call that was occasionally shouted from the tree-tops was shrill and like that of a red-tailed hawk.”

Dr. Elliott Coues (1874) says: “It has an abrupt, explosive outcry, much like that of other species of Woodpeckers, and also an entirely different call note. This sounds to me like a number of rolling r’s, beginning with a gutteral k—k’-r-r-r—each set of r’s making a long syllable. This note is leisurely given, and indefinitely repeated, in a very low key.”

Grinnell and Storer (1924) describe the voice as “a weak wheezy whang or whether.”

Field marks.—Such a conspicuously and uniquely colored woodpecker as the male Williamson’s sapsucker should be easily recognized; its general appearance is largely black, with a large white patch in the fore part of the wing, and another on the rump and upper tail coverts; the yellow on the under parts is not so easily seen; neither is the red throat. The female appears mainly pale brown, with a white rump, brown head, and barred back and wings.

DISTRIBUTION

Range.—Mountainous regions of the Western United States and southwestern Canada south to west-central Mexico.

Breeding range.—Williamson’s sapsucker breeds north to central Washington (Bumping Lake and probably Dayton); and southwestern Montana (Missoula, Pipestone Creek, Bridger Creek, and Red Lodge). East to Montana (Red Lodge); Wyoming (Yellowstone National Park and Laramie Peak); Colorado (Estes Park, Idaho Springs, Breckenridge, El Paso County, and Fort Garland); and New Mexico (Carson Forest, Santa Fe Canyon, Las Vegas, and Hermosa). South to southern New Mexico (Hermosa); Arizona (Tucson, Mogollon Mountains, and Fort Whipple); and southern California (San Jacinto). West to eastern California (San Jacinto, San Bernardino Mountains, Pyramid Peak, Tuolumne County, Echo Lake, Lake Tahoe, Lassen Peak, and Eagle Peak); western Oregon (Rogue River Valley and Foley Springs); and west-central Washington (Bumping Lake).

Winter range.—In winter the species is regularly found north to central California (Yosemite Valley); central Arizona (Pine Springs, Oak Creek, and Mogollon Mountains); southwestern New Mexico (Black Range); and central Texas (San Angelo). East to Texas (San Angelo and probably Kerrville); eastern Chihuahua (Apache); and Jalisco (Bolanos and Guadalajara). South to southern Jalisco (Guadalajara). West to Jalisco (Guadalajara); northwestern Durango; western Chihuahua (Refugio, Casa Colorado, Bavispee River, and Colonia Garcia); northern Baja California (San Pedro Martir, Ville de la Trinidad, and Hanson Lagoon); and California (Pasadena and Yosemite Valley).

As outlined, the range applies to the entire species, which has been separated into two subspecies. True Williamson’s sapsucker (S. t. thyroideus) is found in the Pacific coast region from British Columbia south to Baja California, while Natalie’s sapsucker (S. t. nataliae) inhabits the Rocky Mountain region from Montana south to Jalisco.

Spring migration.—Although the species appears to be resident throughout considerable portions of its range, and but little is known of its migratory movements, the following early dates of arrival have been noted: Colorado—Boulder County, April 5; Colorado Springs, April 5; Evergreen, April 8; Denver, April 15. Wyoming—Yellowstone Park, April 29. Montana—Charcoal Gulch, April 23. Nevada—Carson City, March 10. Washington—Pullman, April 26. A late date of departure from the southern part of the winter range is Chihuahua, Palomas Lakes, April 7.

Fall migration.—Available late dates of fall departure are: Washington—Copper River, September 3. Oregon—Rustler Peak, November 6. Nevada—Lee Canyon, October 7; Carson City, November 27. Montana—Fort Custer, September 9. Wyoming—Yellowstone Park, September 22; Wheatland, October 4. Colorado—Del Norte, September 5; Rio Blanco, September 9; Boulder County, November 6. It has been noted to reach Hanson Lagoon, Baja California, on October 11.

Casual records.—There are a few records in extreme southern British Columbia, where it may breed occasionally. A pair were collected on April 22, 1913, on Schoonover Mountain, near Okanagan Falls; one was taken at Similkameen in June 1882, while Swarth (1917) records three from Midway.