Western Wood-Pewee

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.

Bent Life History for the Western Wood-Pewee – the common name and sub-species reflect the nomenclature in use at the time the description was written.

A study of museum specimens would strongly suggest that riduzrd80124 should be considered a subspecies of virens, but those who are familiar with the two birds in life recognize certain differences in voice and nesting habits that seem to warrant the separation of the western bird as a full species, distinct from our eastern wood pewee. In this connection the reader is referred to a discussion of the subject by no less an authority than Dr. Joseph Grinnell (1928b), who says, after “examination of large series of specimens,” that “there is practically complete intergradation by way of individual variation between richard,sonii and virens, in structural characters. Why should differences in voice or in nesting habits weigh against the use of the trinomial in this case any more validly than they do in other quite similar cases where the trinomial is in current undisputed employment?” Another keen observer, A. J. van Rossem (Dickey and van Rossem, 1938) seems to concur in this view, for he lists the western wood pewee as Myjockanes rirens richardsonii (Swainson). The western wood pewee enjoys a wide distribution, as a summer resident, over the western half of this country, as the eastern bird does over the eastern half. Whether and to what extent the two forms intergrade where their ranges meet does not seem to have been satisfactorily determined.

Samuel F. Rathbun writes to me of its haunts in Washington: “In the Puget Sound region the western wood pewee can be regarded a common summer resident. But, although its distribution is general, for it is found alike in the cities and towns as well as the outside country, I have observed that it is somewhat partial to certain localities and absent from others of the same general character. It shows a liking for some cultivated valley through which a stream flows, or the open deciduous tree growth along the borders of lakes and small bodies of fresh water; and in such localities one can expect to find the species year after year. Seldom are there more than a pair or two of these birds in any certain locality; usually they seem to be somewhat separated.”

James B. Dixon writes to me of California haunts: “This is a common breeder from the Pacific Ocean to the tops of our highest coastal range in San Diego County. It is commoner in the sycamore groves of the stream beds but is found in the conifers of the higher elevations and also is common in the aspen thickets at the higher elevations in the Mono Basin in Mono County.” In Arizona we found the western wood pewee in the lower, more open portions of the canyons where there was a heavy growth of large sycamores, cottonwoods, and other trees along the beds of the mountain streams, at elevations of 5,000 to 6,000 feet but not in the higher portions of the mountains or in the lower valleys.

Nesting: In the choice of a nesting site the western wood pewee shows no special preference for any particular species of tree, provided it can find a suitable fork or horizontal branch on which to place its nest. And nests are often placed on dead branches or on wholly dead trees; dead aspens seem to be highly favored. J. Donald Daynes writes to me from Salt Lake City, Utah, that within an area of 40 acres of aspen trees he found five nests; three of these were in dead aspens and all were on dead limbs; they ranged in height from 10 to 50 feet above ground. Sycamores and cottonwcods seem to be popular trees, and nests have been recorded in walnuts, boxelders, ashes, birches, alders, various oaks, maples, hackberry, and eucalyptus trees, madrones, various pines, larches or tamaracks, cedars, firs, and spruces, as well as orchard trees. W. TI. D. Scott (1879) mentions a nest that “was built where three branches crossed in a brushheap two feet from the ground.” This, of course, is a very unusual location and a very low one; most of the nests are placed at heights ranging from 15 to 30 feet above ground; often they are as high as 40 feet and sometimes 50 or even 75 feet.

Mr. Rathbun writes to me of the nesting habits of this pewee in Washington: “The breeding period of this flycatcher, in this section at least, appears a little extended, or from quite early in June to about the middle of July. Our experience with its nesting habits has shown us that when the first nesu is taken it is very quickly replaced by another. On one occasion when I took a nest, at the end of several days a second had been completed and held an egg. In another instance, on the eleventh day thereafter the new nest had three eggs; and in each case the second nest was placed very near where the first one had been.

“The nest of this flycatcher, though somewhat shallow, is a beautiful one. In the many I have found the materials used consisted of small pieces of plant fibers, often a downy substance from cottonwood blooms, bits of fine dry grasses, and at times a few bud scales of ~mal1 size, all neatly interwoven. This represented the bottom of the nest, which then was decorated outwardly with lichens, bits of grayish moss, now and then a few little bud scales, all skillfully hound thereon by spider webs and filmy plant fibers, with occasionally a few horsehairs. Always the lining was of fine dry grasses. The nests were either saddled on an open branch or attached snugly on a small horizontal fork of a limb, at heights that varied from 15 to 40 feet; and all were placed in deciduous trees of not large size.”

Baird, Brewer, and Ridgway (1905) described a nest from California that differs somewhat from that described above: “The base and sides of this nest are largely composed of the exuviae of chrysalides, intermingled with hemp-like fibres of plants, stems and fine dry grasses. The rim is firmly wrought of strong wiry stems, and a large portion of the inner nest is of the same material. The whole is warmly and thoroughly lined with the soft fine hair of small quadrupeds and with vegetable fibres.”

All the nests I have seen differ from the nests of the eastern wood pewee in being somewhat larger, more compact, and more deeply hollowed; the usual lining of bright-yellow grasses is generally conspicuous; and, most important of all, the outer covering of lichens, so conspicuous in nests of the eastern bird, is usually lacking or replaced with some other material. Most other observers agree on these points, though a number of them have reported some use of lichens. Henshaw (1875), quoting C. E. Aiken, said: “No lichens at all are used in its construction, but instead the gray dead leaves of a minute plant that grows abundantly in the mountains is often found upon the outside.” I am inclined to think that this may be the material that has been mistaken for lichens; also, bits of chrysalids or cocoons, frequently used, look much like pale gray lichens. However, most nests are well camouflaged with a great profusion of spider webs with which the nest is bound to the branch, or with other material that matches the branch. Another point of difference is that some nests of the western bird are more or less lined xvith various bird feathers, sometimes brightly colored ones; these, so far as I know, are never used by the eastern bird.

Many years ago Ridgway (1877) made the surprising statement that “the nest of this species, as is well known, differs very remarkably from that of C [onto pits] virens, being almost invariably placed in the crotch between nearly upright forks, like that of certain Empidonacea, as F. minimius and F. obseurus, instead of being saddled on a horizontal branch.”

Major Bendire (1895) challenged this statement, as being quite at ~’ariance with his experience, and said: “If the Western Wood Pewee places its nest occasionally in a crotch, which I do not deny, it is exceptional and not the rule.” There is, however, some more recent evidence that this pewee does occasionally build its nest in an upright crotch. Mr. Dawson (1923) says that “occasionally the nest is set in an upright crotch of a willow or some dead sapling.” And J. A. Munro (1919) says of the nests found in British Columbia: “They are usually built saddle fashion on a rather large limb, generally at a crotch, but I have found two that were built in upright forks like a Yellow Warbler’s nest. These two nests were in half-dead peach trees in an orchard.”

Major Bendire (1895) quotes Charles E. Aiken as saying: “I have found several settled in the angle formed by the trunk of the tree and a horizontal branch, and in one instance, where a large limb had been torn from the tree by the wind, a nest was placed flatly upon a broad, board-like splinter.”

John W. Mailliard (1921) had some favorable opportunities to watch some western wood pewees at their nest building activities, of which he writes:

One female gathered its building material by pecking small bits of bark from the branches of a dead willow, which was but a few yards from the large yellow pine in which the nest was placed. At times small bits of this material could be distinguished in the bill of the busy bird, while at other times nothing was discerned, the presence of such only being evidenced by the operations of the bird upon its return to the nest. Meantime the male perched in the near vicinity, or darted after its prey, sometimes perching in, or darting from, the very tree in which the nest was being constructed. * * Building operations seemed to consist solely in a constant pecklng.weaving process, and the shaping of the nest was accomplished by the bird twisting its body while in the nest, and arching its neck so that its throat wns over the rim and against the side of the nest. The head was then moved back and forth along the rim much as one sharpens a razor on a strop. With a similar effect the tall was often thrown down and compressed against the outside of the nest, but no lateral motion could ever be discerned.

Another pair built three nests in rapid succession. The first nest was destroyed by a storm, and a new nest was built and the first egg laid within eight days; this nest, with its three eggs, was collected. The third nest was constructed and the first egg laid in it within seven days. All the nests were within a few rods of the first site, and all in aspens.

The measurements of four nests before me show considerable variation in outside diameter, from 4 to 2’/2 inches, but the inside diameter is more constant at about 2 inches; the outside height varies from 11/2 to 134 inches, and the depth of the inner cavity from 1 to 11/4 inches.

Eggs: The western wood pewee usually lays three eggs, sometimes only two, and very rarely four. These are indistinguishable from those of the eastern wood pewee, which the reader will find described under that bird. The measurements of 50 eggs average 18.3 by 13.6 millimeters; the eggs showing the four extremes measure 19.5 by 13.2, 19.1 by 15.0 and 16.0 by 13.0 millimeters.

Young: The incubation period is probably about 12 days. The female evidently does all the incubating, but the male assists in the care of the young. Probably only one brood is raised in a seasonMrs. Wheelock (1904) implies that the male does most of the feeding of the young, and says: “Small butterflies, gnats, all sorts of small winged insects are the orthodox food for infant flycatchers, and axe swallowed at the rate one every two minutes. Nor does the supply ever quite equal the demand, for every visit of the devoted father is welcomed with wide-open mouths and quivering wings. At first all this feeding must be by regurgitation, the adult swallowing the insect first and partially digesting it in some cases, and in others merely moistening it with the saliva. After four or five days most of the food is given to the young in a fresh state.”

Plumages: I can find nothing in the molts and plumages of the western wood pewee that are in any way different from those of the eastern wood pewee; all that has been said about the eastern bird will apply equally well to the western.

Food: Professor Beal (1912) reports on the contents of 174 stomachs of the western wood pewee, in which 99.93 percent of the food was animal matter and only 0.07 percent vegetable. Beetles of 19 species amount to 5.44 percent, of which only 0.95 percent are useful beetles, ladybird beetles, and predaceous ground beetles. Hymenoptera, wasps, bees, and ants amount to 39.81 percent of the food and were found in 107 stomachs, 17 of which contained no other food. Parasitic species were noted in 8 stomachs and ants in 10. No trace of a honeybee was found, and he never heard any complaints against the bird on this score. Diptera (flies) seem to be the largest item of the food, amounting to 44.25 percent. They were found in 162 stomachs, 30 of which were entirely filled with them. They included horse flies, snipe flies, crane flies, robber flies, and house flies. Ilemiptera amount to only 1.79 percent, and no trace of grasshoppers or crickets was found. Moths were found in 24 stomachs and caterpillars in 5, making an average of 5.17 percent for the season. Dragonflies, lacewinged flies, Mayflies, white ants, and spiders together make up 3.47 percent, the remainder of the animal food.

Vegetable matter was found in only four stomachs. “In one of these it consisted of 3 seeds of elderberries (Sambucus); in another, of a bit of fruit skin, with a trifle of rubbish; in another, of one seed of wild oats; and in the fourth, of rotten wood.”

He once watched one of these pewees flying out from its perch for insects “and noted the number caught in three minutes.” He says:

In the first minute 7 were taken, in the second 5, and in the third 6, or 18 in three minutes. These observations were made at 10 A. M., when the air was warm and many insects were on the wing. At 9 A. M. the next day the same perch was again watched, and 17 captures were noted In 8 minutes. This morning was much cooler than the previous one and fewer Insects were abroad. The mean of these two observations is 4 insects per minute, and if this rate is kept up for even 10 hours a day, the total is 2,400 Insects. It seems hardly possible that one bird can eat so many unless they are very small, but this bird Is rarely seen when it is not hunting. When there are young in the nest to feed, the havoc among the insects of that immediate vicinity must be something enormous.

In spite of the fact that Professor Beal found no traces of honeybees in the 174 stomachs that he examined, some do occasionally eat bees, for Frank Stephens wrote to Major Bendire (1895): “I have known apiarists to be compelled to shoot a great many to protect their bees; one in San Diego County told me that he shot several hundred in a season. They capture both workers and drones, and I have examined many stomachs which had stings sticking in them.”

Dr. A. K. Fisher (1893) says that, in Death Valley, “one day, when the wind was very high, a number were seen sitting on the bare alkaline flats near the [Owens] Lake, where they were picking from the ground the flies which swarmed there, as grain-eating birds do seeds.”

Behavior: In a general way the habits and actions of the western wood pewee are similar to those of its eastern representative. It sits in a vertical attitude for long periods on the top of some dead tree, or oftener on a dead branch on the edge of the woods or under the shadow of the open forest, whence it makes frequent sallies into the air after insects and returns to its lookout perch. Fruit orchards and shade trees about houses are also often used as hunting grounds. It is very lively in its movements, darting about in the air after its prey, which it seizes with a click of the mandibles. It is a most industrious and persistent flycatcher, spending most of its time in the pursuit of these tiny insects, of which an enormous number seems to be needed to satisfy its appetite.

As a rule, it seems to be quite tolerant and peaceful toward its avian neighbors, but it knows how to discriminate between the harmless and the dangerous ones. Jays and other nest robbers are immediately attacked by the guarding male, if they venture too near the nest; with cries of protest and much snapping of mandibles, the unwelcome visitor is set upon, driven away, and pursued relentlessly until forced to leave the territory. Mr. Rathbun writes to me: “If their nest is disturbed the birds show much excitement, not only by giving their notes often and continually shifting from one perch to another, but at times one of the pair will make a feint to strike the intruder; and these actions continue as long as they are molested.”

Voice: Mr. Ridgway (1877) states that it seems “to be more crepuscular than the eastern species, for while it remains quiet most of the day, no sooner does the sun set than it begins to utter its weird, lisping notes, which increase in loudness and frequency as the evening shades deepen. At Sacramento we frequently heard these notes about our camp at all times of the night. This common note of Richardson’s Pewee is a harsh, abrupt lisping utterance, more resembling the ordinary rasping note of the Night-Hawk (Oltordeiles popetue) than any other we can compare it with, though it is of course weaker, or in strength proportioned to the size of the bird. Being most frequently heard during the close of the day, when most other animals become silent and Nature presents its most gloomy aspect, the voice of this bird sounds lonely, or even weird.”

Mr. Rathbun (MS.) says that “the note of this flycatcher is similar to that of its eastern relative, although it is more abbreviated; but it has the same plaintive cadence so suggestive of the drowsy summer days.

Dr. Loye Miller (1939) in his study of the song of the western wood pewee writes it tewee-tee-teet, tewee-tee-teet, brew, and says: “The t8wee-tee-teet is designated as a triad, it is once repeated and is then followed by brew, a downward slur, which completes the pattern of three equal measures. This pattern is then repeated without interruption of rhythm for an extended and metronomic performance. Each measure lasts for about one and a half seconds. The triad is a rising sequence with the strong accent on the first note. The slur is a downward slide equivalent in length to the three rising notes of the triad. The tone quality of the triad notes is entirely different from that of the slur, the latter being a roughened buzz, whereas the former are clear and sweet.”

What is apparently the same song has been expressed in various syllables by different observers, but all seem to give the same impression. The doleful “dear me” written by Dawson (1923), appeals to me as expressing the tinge of melancholy that the song of the wood pewee always suggests to me; it is not a particularly joyful song.

Ralph Hoffmann (1927) describes another song as follows: “When a pair are together in the mating season they utter a hoarse, gurgling note, oh e-up cUe-up, and the male encourages the female during the nest-building by a musical pip, pip, pip, pip, pie-a, or at times mounts into the air and flies about calling pit, pit, pit.”

Field marks: T he wood pewee is only slightly larger than the other small flycatchers, and it has no very conspicuous field marks. The dark sides of the breast are divided by a narrow, light-colored line, there are no very conspicuous wing bars, except in the young bird, and it lacks the white eye-ring, so prominent in the Empidonaces.

Its habitat is different from those of the other small western flycatchers, and its notes are quite distinctive.

Enemies: Dr. Friedmann (1929) says that “this species seems to be a rather uncommon host of the small, southwestern race of the Cowbird: the subspecies 068 cUrU8.”

DISTRIBUTION
Range: Western North America, south to northwestern South America.

Breeding range: The western wood pewee breeds north to central Alaska (Fairbanks and near Circle); southern Yukon (Little Salmon River); southwestern Mackenzie (Fort Simpson, Fort Providence, and Fort Smith); northeastern Alberta (Athabaska delta); central Saskatchewan (Big River and Cumberland House); and southeastern Manitoba (Winnipeg). East to eastern Manitoba (Winnipeg and Treesbank); northeastern North Dakota (Grafton); southwestern South Dakota (Elm Mountains and Hot Springs); western Nebraska (Henry); central Colorado (Fort Collins, Denver, and Beulah) ; eastern New Mexico (Montoya and Roswell) ; western Texas (Fort. Hancock); Veraeruz (Perote and Presidio); Guatemala (Progreso); and Costa Rica (La Hondura and Boruca). South to Costa Rica (Boruca); Chiapas (Tonala); Guerrero (Chilpancingo); and southern Baja California (San Jose de Rancho and La Laguna Mountain~). The western limit of the breeding range extends northward along the Pacific coast from Baja California (La Laguna Mountains and the San Pedro Martir Mountains) to Alaska (Chickamin River and Fairbanks).

Winter range: The winter range of this species is imperfectly known, but at this season it appears to be concentrated in Central America and northwestern South America. It has been recorded north to Gaxaca (Topanatepic) and south to Bolivia (Nairapi) and Peru (La Gloria and La Merced).

As outlined the range includes three currently recognized subspecies. The typical form (Myioekane~ richard8oni rickardsoni) is found in summer from Alaska and Mackenzie south to northern Mexico and in winter south to Ecuador, Bolivia, and Peru; the large-billed wood pewee (M. r. peninsulae) breeds in southern Baja California and is found in winter on the mainland of Mexico and south to Guatemala; the third form, the Mexican wood pewee (M. r. sordidulAts), breeds in the highlands of southern Mexico and winters south to Peru.

Spring migration: Early dates of spring arrival are: Texas: San Antonio, April 15. New Mexico: State College, April 25. Colorado: Boulder, May 3. Wyoming: Cheyenne, May 13. Montana: Columbia Falls, May 20. Saskatchewan: Eastend, May 20. Manitoba: Aweme, May 17. Arizona: Tombstone, April 21. Utah: S~lt Lake City, May 8. Idaho: Rupert., May 6. Alberta: Edmonton, May 8. California: Buena Park, April 14. Oregon: Coos Bay, April 28. Washington: Yakima, May 3. British Columbia: Chiliwack, May 9. Alaska: Fairbanks, May 12.

Fall migration: Late dates of fall departure are: Alaska: Taku River, September 8. British Columbia: Okanagan, September 13. Washington: Pullman, September 15. Oregon: Coos Bay, October 1. California: Buena Park, October 2. Alberta: Camrose, August 28. Idaho: Preston, September 8. Arizona: Huachuca Mountains, October 29. Saskatchewan: Eastend, September 8. Montana: Missoula, September 10. Wyoming: Laramie, September 30. Colorado: Fort Morgan, October 10. New Mexico: Mesilla Park, October 25. Manitoba: Aweme, September 13. Oklahoma: Kenton, September 26. Texas: iRunge, September 21.

Casual records: According to Kumlien and Hollister (1903) several typical western wood pewees have been taken at Lake Koshkonong, Wis., one pair of which with their nest and eggs, were identified by Dr. Elliott Coues. Dr. A. K. Fisher also has so identified a specimen taken on July 31, 1890, at Alden, Wis. There are no known recent records. One was collected on July 1, 1898, at Point Barrow, Alaska.

Egg dates: California: 100 records, May 9 to August 1; 50 records, June 10 to 27, indicating the height of the season. Colorado: 9 records, May 6 to July 7. Oregon: 14 records, June 4 to July 18; 8 records, June 18 to July 3.

Washington: 7 records, June 3 to July 22.

LARGE-BILLED WOOD PEWEE
MYIOCHANES RICHARDSONI PENINSULAE (Brewster)
HABITS

When William Brewster (1891) described and named this Lower California subspecies of the western wood pewee he characterized it as “much smaller than the northern race, the color of the upperï parts slightly grayer, the yellowish of the throat and abdomen clearer or less brownish and more extended, the pectoral band narrower and grayer, the light edging of the inner secondaries and greater wing-coverts broader and whiter.”

He also said: “In the coloring of the under parts this form resembles C. virens, the yellowish of the throat and abdomen being of about the same shade and fully as extended as in that species. The breast and sides, however, are less olivaceous and more as in riokardsonii, but grayer, with the pectoral band almost invariably narrower. The coloring of the upper parts is essentially similar to that of rickc’rdsonii, but perhaps a trifle paler. The wings and tail are much shorter or about as in virens. The bill averages considerably larger (both longer and broader) than in either virens or richardaonii.”

About all we know of its distribution and habits is contained in the following statement by Mr. Brewster (1902) “This near ally of C’. riekardeonji was discovered by Mr. Frazar on the Sierra de Ia Laguna, where it appeared about the middle of May, the males arriving two weeks in advance of the females. It soon became very common, frequenting open places in the woods, and usually taking its station at the extremity of some dead branch. Its note is ‘a sharp cutting pee-ee-e, the second syllable with a falling, the last with a rising, inflection.’ On June 9 while descending the mountain Mr. Frazar found these Flycatehers common to its base as well as afterwards at Triunfo and San Josd del Rancho. An adult female killed on June 20 at Triunfo was incubating, but no nests were found.”

The measurements of three eggs, all that 1 have been able to secure, are 19.0 by 15.6, 18.7 by 15.6, and 1815 by 15.3 millimeters.