Least Flycatcher

The Least Flycatcher has grayish-olive upperparts, faintly yellow underparts with a gray wash across the breast, an eye ring, and a mostly orange lower mandible.  Length: 5 in.  Wingspan: 8 in.

Photograph © Greg Lavaty.

Sexes similar.

Wider wing bars are present in the fall.

Juveniles resemble adults but have tawnier wing bars.

Woodlands.

Insects.

Photograph © Greg Lavaty.

Forages by flying from a perch to catch insects in flight.

Breeds across the northern U.S. and much of southern and central Canada and winters in Mexico and Central America.

More information:

Bent Life History

Visit the Bent Life History for extensive additional information on the Least Flycatcher.

Least Flycatcher individuals generally do not return to the same breeding area in subsequent breeding seasons.

Least Flycatchers tend to exclude American Redstarts from their breeding territories.

The song is a dry “che-bek” with the second syllable louder. The call is a “whit”.

The nest is a cup of plant material placed in the fork of a small tree.

Number: 4.
Color: White.

Incubation and fledging:
Young hatch at 13-15 days.   ?- Young fledge (leave the nest) in 12-17 days after hatching but remain with the adults for some time.

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 Least Flycatcher – the common name and sub-species reflect the nomenclature in use at the time the description was written.

The familiar little “chebec,” as we used to call it, is widely distributed in the Canadian and Transition Zones of eastern North America, where it is a common and well-known summer resident. In the more thickly settled regions it has become adapted to the environments of human habitations and makes itself at home in our orchards and gardens, in the shade trees about our houses, along the streets of towns and villages, and even in our city parks. It is equally at home along country roads, the borders of streams and ponds, in partially overgrown pastures, and on the edges of the woods. It frequents the more open woodlands,- rather tfhan the denser forests, but shows a decided preference for the rural countryside. On an early morning walk, in spring, along a New England country roadside, one is almost sure to see this sprightly little bird, or at least hear its familiar “chebec.”

The least flycatcher extends its summer range northward in Canada as far as it can find deciduous tree growth suited to its needs, where it seems partial to thickets of balsam poplar and quaking aspen; here it also frequents groves of willows along the shores of lakes, and thickets of birches and maples along the streams.

Prof. Maurice Brooks writes to me: “Least flycatchers are summer residents of the Alleghenian division of the Transition Life Zone. In places they are abundant, their nests placed in either deciduous or coniferous trees at 10 to 20 feet from the ground. They occur in 1,Vest Virginia at elevations ranging from 1,500 feet to 3,300 feet. I have never found them in the red spruce belt, although they closely approach it.”

Referring to the same general region, Dr. Samuel S. Dickey (MS.) writes: “While most pairs of these birds seemingly prefer to inhabit apple orchards, some of them frequent mixed tracts of pines, spruces, hemlocks, oaks, and birches. They are heard venting their calls from thickets of alders, silky dogwood, winterberry, and mountain holly.”

Spring: Writing of the least flycatcher in Massachusetts, Mr. Forbush (1927) says:

The bird arrives in spring before the other small flycatchers. A few Individuals are here ere the end of April, and when a thousand orchards burgeon with the bloom of spring, when the first misty green begins to screen the woodlands, a host of these little feathered warriors spreads over New England. At first, In migration, they are rather silent and appear wherever open spaces among the trees or along the edges of thickets gives them fly-room. At this time they may he mistaken for the Alder Flycatcher, as they may frequent alders along a brook and may even appear among the tall bushes at the edges of the meadows. Later, when the females come, the males are the most vociferous and pugnacious of their kind, and nearly every orchard resounds with their cries.”

Courtship: As soon as the females arrive courtship begins in earnest. The males are then the most active, noisiest, and most pugnacious of any of our small birds. Rival males indulge in frequent combats, fighting furiously until the vanquished is driven away among the foliage in search of hidden females, and the latter are chased about in pursuit flights through the leaf age, across clearings and over the open spaces, until the successful suitor proclaims his victory with many vigorous eke bees and much flirting of wings and tail. The pair is then ready to select its nesting site.

Nesting: In southern New England the least flycatcher shows a decided preference for apple trees as nesting sites; at least two-thirds of the nests that I have recorded in Massachusetts have been in apple trees in old orchards near houses; in such situations the nests have been placed on horizontal branches, usually partially supported by upright twigs, or in an upright fork of some small branch. In my egg-collecting days, old and partially neglected orchards were always considered favorable places to look for the nests of this and several other species of small birds. We have also found the least flycatcher nesting rather commonly on the pine barrens of Plymouth County, Mass., where there was a scattering growth of small or medium-sized pitch pines, with an undergrowth of scrub oaks and other underbrush; here I have found as many as three nests in a short walk. Some of the nests were placed near the ends of horizontal branches and others against the trunks of the smallest pines at heights ranging from 7 to 15 feet above ground. But other nests in southern New England and New York have been found in pear trees, maples, willows, oaks, alders, sycamores, locusts, beeches, elms, birches, sumacs, wild cherries, and others. In northern New England, nests have often been found in spruces, tamaracks, and other conifers. William Brewster (1937) says that, in the neighborhood of Umbagog Lake, Maine, “their nests are usually built in balsams, hemlocks, or other evergreen trees and commonly lined much more profusely with feathers than are those found in eastern Massachusetts.”

In Canada, favorite trees are yellow and paper birches, qualnng aspens, balsam poplars, and mountain-ashes, as well as the conifers mentioned above. Near James Bay, Canada, Dr. Dickey tells me that he found many nests of this flycatcher in dense growths of speckled alder, red osier dogwood, quaking aspen, balsam poplar, and various willow shrubs; the nests were 2 to 6 feet above ground, and “were adorned with mats of white hair from the husky dogs and feathers plucked last autumn from ‘wavey geese’ and other wild fowl.”

The nests of the least flycatcher are seldom more than 25 feet from the ground, usually much less in eastern and northern localities, but A. Dawes DuBois has sent me some notes on Wisconsin and Minnesota nests that were much higher; one was about 50 feet up in an elm, one 40 or 50, and another about 60 feet from the ground. IHe watched the bird building the latter nest, and says: “One of these little flycatchers, after gathering some material on the ground, flew to a fallen birch, took from it some fine, thin shreds of birch bark, and mounted into the tree above me. It worked at the nest about 10 seconds, flew away and was gone two minutes, then worked at the nest 25 seconds, and was gone again for about two minutes on another material-gathering errand.”

One that I saw building worked equally fast, returning to the nest with material every three or four minutes. Mr. Forbush (1927) says that the building of the nest usually occupies from six to eight days. A. A. Cross wrote to him about watching the building of a nest that was nearly finished:

About one half of the upper edge seemed literally torn to pieces, the frayed fragments projecting in all directions. The work of some robber, I thought. Such was not the case, for presently the owner appeared with her beak full of building material which, a piece at a time, she thrust Into tbe edge of the nest, leaving the loose ends free. Watching her, I noted that she was gathering the Inner bark from the dead and broken stems of last year’s goldenrod. She made many trips, working rapidly, and disposing of the material as In the first case. In about 20 mInutes she had finished, causing the edge of the nest to look like a miniature hedge. She then settled herself solidly In the nest, hooked her head over the edge and pivoting on her legs Ironed out the rough brim with her throat, putting considerable energy Into the work and working first one way and then the other. In this manner she was able to take In about one-third of the circumference of the nest before changing her position. Then readjusting herself, she continued the process until the nest was finished. This was the last step In the building of the nest.

The nest is compactly and well made, firmly settled down into a crotch or firmly attached to twigs arising from a horizontal branch, resembling in these respects certain nests of the yellow warbler or the redstart. It is deeply cupped, the walls are rather thin, hardly any material intervening between them and the supporting forks, and the upper rim is often somewhat incurved. The body of the nest is made of shreds of the inner bark of trees, shredded bark of coarse weeds, bits of string and paper, fine weed stems and grasses, the dried blossoms of weeds and grasses, thistledown and the down from cottonwoods and ferns, cotton, shreds of rope, spider webs and cocoons, and various other vegetable fibers and rubbish. The rim is neatly finished off with the finest of the fibers and grasses, firmly interwoven or pressed down into place. The cup is smoothly lined with the finest of grasses, cow’s hair or horsehair, thistle, milkweed, dandelion, willow, or cottonwood down, and a few feathers. Nests that I have measured vary from 3 to 21/2 inches in outer diameter; from 2 to iy4 inches in inner diameter; in outside height from 2½ to 13/4 inches; and the inner cavity varied from 11/2 to 11/4 inches in depth.

Eggs: Bendire (1895) says that the number of eggs laid by the least flycatcher varies from three to six, usually four, and that one is deposited daily. I have never seen more than four eggs in a nest and think that any larger numbers must be rare. A set of seven, reported by Dr. Dickey (MS.), was apparently the product of two females. The eggs are ovate, short-ovate, or rounded ovate and are not glossy. They are creamy white and unmarked. The measurements of 50 eggs average 16.1 by 12.9 millimeters; the eggs showing the four extremes measure 17.8 by 12.2, 16.8 by 15.0, 15.0 by 12.7, and 15.2 by 11.4 millimeters.

Young: The period of incubation is said to be 12 days. Probably both sexes incubate; some observers state so positively, and others are more or less in doubt about it. But certainly both parents assist in the feeding and care of the young, for both have been seen at the nest together. Often, if not regularly in the southern portion of its range, two broods are raised in a season; and sometimes the second brood is raised in the same crotch.

Ralph Hoffmann (1901) removed an empty nest after the young had left it, and says: “When the young had been out two days, and were being fed constantly by the male, I saw the female fly to the empty crotch, where the old nest had been. In a moment she repeated her visit, and when I walked to the tree, I saw the skeleton of a new nest already completed. Tw.o days later the nest was finished. It was interesting to note that the beginning of the new series of instinctive acts involved in raising a second brood did not destroy the force of the last series, for when the nest was finished the female returned to help the male feed the first brood.”

Miss Mildred Campbell has sent me some elaborate notes on her observations made at a nest of young least flycatchers in Michigan, from which I quote as follows: “The adults covered the eggs day and night. The incubating bird’s body movements indicated that the eggs were being turned at intervals. Nestlings were hatched on June 29, June 30, and July 1, respectively. The pieces of shell were carried from the nest by the adults. After 24 hours the largebellied, naked nestling began to stretch for food.”

During the 11 days in the nest a young bird increased in weight from 1.42 to 8.21 grams. Down appeared ~n the third day, pinfeathers on the fourth and sixth days, eyes opened on the eighth day, and on the eleventh day the young bird was completely feathered.

“The nestlings were fed by regurgitation of both male and female at first. Later a diet of captured craneflies, Mayflies, grasshoppers (mainly nymphs), beetles, ~piders, and harvestmen, with some light green food (unidentified) was brought to the young. The nestlings were fed in rapid succession in a more or less definite order. When no attempt was made to swallow food pressed into the young throat, the morsel was removed and placed in another gaping mouth. During my observation, the greatest interval between feedings was ~4 minutes. The birds were fed heavily from 4: 40 until 10: 40 A. IkE. and from 2:00 until 6: 00 p~ M. A sudden increased demand for food came just before the young prepared to fly from the nest. Usually one bird was fed per visit, but several times two were fed on the same occasion.

“The adults fed the nestlings and waited for the voided ‘excreta sac’, which was picked up and removed from the nest. The rim of the nest became badly worn by the continuous activity, so that the young soon were able to void the ‘excreta sac’ over the side of the nest.

“The diurnal brooding period decreased rapidly from day to day. On very warm days the adults relieved one another during the heat of the day. One and then the other remained astride the nest, with outstretched wings, keeping the young from suffocating and from the torrid rays of the sun.

“The nestlings pushed and turned, stretched and preened their wings, and spread their tails. Much of this was done from the rim of the nest, and then the young dropped down in the nest in order to keep from going overboard during this activity. The first one left the nest during the evening of the eleventh day, the second on the morning of the twelfth day, and the third one preened and stretched on the rim and in the bottom of the nest all day. Food was caught as the parents flew by this fledgling. Finally, in the evening, this one dropped from the nest and balanced itself on a bouncing twig. Here it was fed and then led away by the parents.”

Observations by Aretas A. Saunders (1938) and his students on a nest in Allegany State Park, N. Y., “show that the parent fed the young 24 times an hour, as an average, in 133,4 hours of observation. The times varied, however, with the age of the bird and the time of day, the least number being seven feedings an hour and the greatest 37. Apparently the greatest amount of feeding in an hour was in the morning between 9 and 11 o’clock.”

Plumages: The natal down is said by Dr. Dickey to be light gray (MS.). Dr. Dwight (1900) describes the juvenal plumage of the least flycatcher as follows: “Above, including sides of head, olivebrown, greener on the back, a faint ashy gray collar. Wings and tail deep olive-brown, median and greater coverts edged with pale buff forming two wing bands, secondaries and tertiaries with dull white. Below, grayish white, a smoky gray pectoral band; pale primroseyellow on abdomen and crissum. Orbital ring dull white. * * * The species in this plumage is not so green above as E. virescen.~, but browner and very like F. t. aliwrum from which it may be differentiated by its grayer lower parts, somewhat paler wing bands and smaller bill.”

The postjuvenal molt is mainly accomplished after the young birds migrate southward, but some birds “become greener above and yellower below before they leave for the south late in August.” What first winter birds I have seen are much greener above and yellower below than the adults. There is a first prenuptial molt during the winter, or early spring, which is apparently complete and produces a plumage like that of the adult.

Adults evidently follow the same sequence of molts and plumages as m flaviventris and trailli, having a postnuptial body molt in fall, after arriving in the south, a wing molt during winter, and a prenuptial body molt during the early spring, before coming north.

Food: Professor Beal (1012) says of the least flycatcher: “It is a typical flycatcher in food habits, but like most others of the family it does not take all of its food upon the wing. The writer has seen one scrambling about on the trunk of a tree and catching insects from the bark like a creeper.” In his study of the food, 177 stomachs were examined taken within the months from April to September. “The food consisted of 97.83 per cent of animal matter and 2.17 of vegetable. * * * Hymenoptera are the largest item, * * * 41.10 per cent. * * * Three stomachs were entirely filled with ants and four with other Hymenoptera. Parasitic species were eaten to the average extent of 11.66 per month. * * ~ This percentage is higher than is desirable.”

He lists 67 species of beetles as identified in the food, but useful beetles amount to only 1.41 percent, and harmful beetles total 19.94 percent. The average for Hemiptera is 11.12 percent, for Diptera 11.34 percent, for Orthoptera 2.59 percent, and for Lepidoptera, beth moths and caterpillars, 7.27 percent. “Ephemerids found in one stomach, dragon flies found in 3, and an unidentified insect in 1, make up 0.95 per cent. One stomach was entirely filled with a large dragon fly. Flycatchers are among the comparatively small number of birds expert enough to catch dragon flies on the wing, and these insects are too wary to be taken sitting. Spiders are eaten to a small extent in every month in the season * * * 2.11 per cent.”

Of the vegetable food he says: “Fruit amounts to 1.83 per cent, and consists of Rubus seeds found in 2 stomachs, elderberry seeds in 2, pokeberry seeds in 1, rough-leaved cornel in 1, and fruit skins not further identified in 4. Various seeds were contained in 6 stomachs, and rubbish in 3; altogether they amount to 0.34 per cent.”

W. L. McAtee (1926) says that “insects injurious to woodlands which are eaten by this flycatcher include carpenter ants, gipsy moths, click beetles, leaf beetles, nut weevils, tree hoppers, leaf hoppers, and leaf bugs.” To this list might be added cankerworms, or inchworms, which it catches in the air as the worms spin down to the ground on their webs. The bird also picks off many of these and other caterpillars from the leaves while hovering in the air.

Dr. Dickey writes (MS.) : “Once a flycatcher performed a singular, spiral flight, a distance of 8 yards, to pursue over a little glade a speeding beefly (Bomb yci11u8). They are prone to approach spider webs and small caterpillars that dangle from silken cords. They lean out from twigs and cleanse the webs of these desiderata. They even mount high in dead branches, scan the nooks and corners, and show by their every movement that they are finding the nourishment conducive to their sprightliness. Rarely I observed a flycatcher pass close to the ground, brush almost the tops of sickle sedges, and snap some stray bug, then return to an alder branch to devour it.”

Behavior: Mr. Forbush (1927) says that the least flycatcher “is the smallest, earliest, tamest, smartest, bravest, noisiest, and most prominent member of its genus in New England,” and it is certainly entitled to all these superlatives. The earliest arrivals are much in evidence, as their emphatic calls advertise their presence in our orchards and gardens, as well as everywhere in the open countryside, along roads and on the borders of the woods. One does not have to look far before he sees the trim little warrior perched upright on some bare twig, the top of a post or on a convenient wire, or even on the top of some low bush or tall dead weed stalk. He shows his tameness, or his indifference to our presence by darting out to snatch some passing insect so close to our head that we can plainly hear the snapping of his bill. He is a restless, active little fellow, far less sedate than our wood pewee, preferring to dart ab.out among the foliage, or from one perch to another, in quest of his prey, rather than sit on one favorite perch and watch for it.

He is a sociable and friendly little fellow toward human beings. Manly Hardy wrote to Major Bendire (1895) “A pair of these birds or their descendants have nested regularly in or near my garden, usually building in a maple. These birds know me, and, what is more, I believe remember me from one year to another. They often sat on a dry twig, or on a bean pole near by, and watched me hoe, and suddenly one would dart down and catch a moth or other insect which I had disturbed, flying so close to me that I could distinctly hear the sharp snap of its bill. Then it almost invariably returned to the place it darted from to eat its prey. Both birds often came close to the window and watched my family inside.”

But during the nesting season it is not so friendly toward other birds; it then becomes pugnacious and drives away from the vicinity of its nest, with vicious attacks, almost any small bird that ventures too near. Even the gentle migrating warblers that are peacefully hunting for food among the foliage are quickly put to rout. Mr. DuBois tells me that “a least flycatcher drove an English sparrow out of a tree in the orchard by flying at the sparrow while fiercely snapping its bill.” But he also mentions a nest of this flycatcher that was only about 5 feet from a wood pewee’s nest in the same tree. “The pewee was sitting in her nest while the least flycatcher was building.”

Mr. Forbush (1927) quotes the following notes from F. H. Mosher:

A pair of Least Flycatchers had just begun their nest in an apple tree by placing some bunches of cottony material and a few strings and straws. A female Oriole, happening along, appropriated the string for her own use, and carried it away. The Flycatchers came soon after, and were very much disturbed on finding the nest materials scattered, and had quite a talk over it. In a few moments the Oriole came back for more string, when both Flycatchers flew at her and snapped their bills savagely in her face. The Oriole did not seem to mind them much, and kept on going toward the nest. When the Flycatchers found they could not scare her In this way, they both attacked her fiercely, and pulled out quite a number of feathers, keeping up quite a steady scold. The Oriole attempted to retaliate, but when she attacked one of the Flycatchers the other struck her from the other side, and several times she was knocked completely off the hraach. Finally she heat a precipitate retreat, one of the Flycatchers chasing her out of sight.

After the nesting season is over it becomes much less quarrelsome and less noisy; then, according to Dr. Thomas S. Roberts (1932), “it wanders away from the woodlands and may then be found with the Sparrows and fall Warblers in dense growths of tall weeds and composites, where, with the Warbiers, it finds abundant insect food while the Sparrows feast on the seeds. The top of a rigid mijilein stalk or wild sunflower furnishes a suitable vantage-point from which to sally out after the flying insects that constitute the bulk of its food.”

About its nest the least flycatcher is very tame and brave, often allowing a close approach and making a brave attempt at defense. Professor Brooks tells me of a remarkable case of close sitting; he and his companions sawed down a small hemlock in which one of these flycatchers was incubating its eggs; “the parent bird remained on the nest until the tree had fallen, only leaving it when” they “approached the nest.” Dr. Roberts (1932) tells of one that he stroked and then lifted her off her set of heavily incubated eggs.

Voice: During spring and early summer, or until its nesting activities absorb too much of its tline and attention, the least flycatcher is a noisy bird, and its voice is heard almost constantly, especially during the early morning, when it is one of the first birds to be heard, and toward evening. But after the end of June its vocal efforts slow down, and after the middle of July it is seldom heard. By far the commonest and most characteristic note, from which one of its popular names is derived, is the emphatic 2-syllable chebe5, strongly accented on the last syllable, given with much vehemence, and accompanied with an upward jerk of the head and a flirt of the tail, as if asserting his independence and authority over his domain. This note is so much a part of the bird that it is often combined with some of its other notes, which are not numerous and not so often heard. Mr. DuBois writes to me that this note sounds to him more like te-bic~, which holds true for all these flycatchers that he has heard anywhere. Others have spelled the syllables slightly differently.

It also has a short call note, or alarm note, that sounds like whit. Dr. Dickey writes to me that “at mating time and around disturbed nests they cause the underwoods to resound with noises that sound like speetz and aperk.” Miss Campbell tells me that, at the nest she was watching, “twice, once at noon and another time in the evening, the male sang an unusually melodious warbling song and the female on the nest responded by soft murmurings and rhythmic movements.” Forbush (1927) refers to “a flight-song (?) a ‘twittering warble’ “. E. A. Samuels (1883) says that the bird sometimes changes his chebec note into “ekebec-tr~ee-treo, chebec-treee-cheu.” Dr. Chapman (1912) writes: “In crescendo passages he literally rises to the occasion, and on trembling wings sings an absurd ckebe~ tooral-ooral, chebe6, tooralooral, with an earnestness deserving better results.” H. D. Minot (1877) mentions “querulous exclamations (wkeu, wheu, wheu) which are more or less guttural and subdued.”

Dr. Winsor M. Tyler sends me the following notes on the voice of the least flycatcher: “After listening to the chebec’s song thousands of times with the question of stress in mind, I can detect little difference in the accent of the two syllables. The song suggests to me the words a ahip, snapped out emphatically, enthusiastically, like a mariner sighting a sail at sea. The bird sometimes varies its singing by running several songs into a quick series. At a distance this form resembles the house sparrow’s reiterated chillip. On June 13, 1915, I saw a least flycatcher fly across a field: a distance of 75 yards: singing a jumble of notes in which his regular eke bec occurred frequently. He alighted high in an apple tree, presumably for the night, for it was almost dark.

“The bird is an incessant singer. I have heard it repeat its song about once a second, with occasional pauses, for two hours or more. My notes state: ‘On June 18, 1912, the chebec woke at 8: 18 A. M. Once in the course of a minute he sang 60 times; during another 60 seconds, he sang 75 songs.’ When out of doors in the night, long before day, I have heard several times a sharp chebec suddenly crack out of the darkness above my head.”

Field marks: The least flycatcher looks much like a small, chunky wood pewee, with a more prominent eye ring and with more extensively white under parts. Compared with the other small flycatchers of the Ernpidonaa~ group, it is much whiter below, with hardly any tinge of yellow, and the wing bars are much whiter; furthermore, it is the smallest of the genus within its summer range. Its aommon note is the most distinctive of all, and its haunts and habits are quite different from those of the others, always active, brave, and conspicuous. It could hardly be overlooked or mistaken.

Enemies: Like all ether small birds this flycatcher is preyed upon by many predatory birds and mammals. G. Bartlett Hendricks (1983) tells of an attack on a least flycatcher and its young by two gray squirrels. A gray squirrel was seen to run up a tree with the adult in its mouth. It “halted half way up the tree and proceeded to eat the bird. * * * In the meantime, another gray squirrel was stalking the first bird,” which was rescued.

William Brewster (1906) writes: “The last nest that was built in our garden (in 1895) was attacked by a large troop of English Sparrows when it contained young about half grown. Although both parents defended it with utmost spirit, the Sparrows succeeded in tearing away part of the outer walls of the nest, and one of them, standing on its rim, bent down and delivered several murderous but fortunately ineffective pecks at the heads of the young. In the end the Flycatchers triumphed and put the cowardly horde to ignominious flight.”

Dr. Friedmaun (1929) says that the least flycatcher is “an uncommon victim” of the cowbird; he found only 10 records.

Fall: After the breeding season is over and the young are strong on the wing, old and young scatter about and mingle with the early migrating warblers and other small birds. During the last week in August the southward migration from Canada and the Northern States begins, numbers decrease during the first half of September, and by the end of that month most of these flycatchers have left their northern homes. The migration is mainly southwestward through Texas and into Mexico and Central America, where they make their winter home.

Winter: Dickey and van Rossem (1938) say that the least flycatcher is “common in fall, winter, and spring throughout the Arid Lower Tropical Zone” in El Salvador, between September 3 and April 22. “The species is most numerous below 2,500 feet, and rare and Local as high as 3,500 feet. * * * The least flycatcher occurs over the same country occupied by Empidonaxo flaviventrie. The two are present in about the same numbers, relatively, and both are found in similar situations, that is to say, undergrowth in the woods, mimosa thickets, shrubbery along watercourses, or in the top foliage of low, open woods.”

William Beebe (1905) reports, in Mexico, “a small, loose flock observed several times near camp in a lower barranca; the only flycatchers which seemed to remain together in any association which could be called a flock.”

DISTRIBUTION
Range: North and Central America, chiefly east of the Rocky Mountains.

Breeding range: The least flycatcher nests north to southwestern Mackenzie (Willow Lake River and Fort Rae); northern Alberta (Smith Landing and the Athabaska Delta); Saskatchewan (Lac he ~ la Crosse and Reindeer River); Manitoba (Oxford Lake); Ontario (Lac Seul .and Moose Factory); southern Quebec (St. Joachim and Restigouche Valley); Nova Scotia (Baddeck); and Prince Edward Island (Malpeaque. East to Nova Scotia (Baddeck and Halifax); Maine (Macbias and Portland); Massachusetts (Cape Cod); Connecticut (New Haven); New York (New York City) ; southeastern Pennsylvania (Hamburg); western Maryland (Accident); West Virginia (Sago and Cranberry Glades); western Virginia (Blacksburg); and western North Carolina (Piney Creek, Rock Mountain, and Waynes 224 BULLETIN 179, UNITED yule). South to southwestern North Carolina (Waynesville) ; Indiana (Worthington); southwestern Missouri (Marionville); southeastern Nebraska (Falls City); and southeastern Wyoming (Cheyenne). West to Wyoming (Cheyenne and Careyhurst); Montana (Livingston, Bozeman, and Great Falls); Alberta (Midnapore and Jasper Park) ; eastern British Columbia (Peace River Block) ; and southwestern Mackenzie (Willow Lake River).

Winter range: In winter this species is found north to rarely Durango (Tamazula); northern Tamaulipas (Matamoros); Yucatan (Merida and Chichen Itza); and Quintana Roo (Cozumel Island). East to Quintana Roo (Cozumel Island and Xcopen); British lionduras (Orange Walk and Belize); Honduras (Tela, Lancetilla, and Progreso); and Panama (David). South to Panama (David); Costa Rica (Nicoya) ; El Salvador (Puerto del Triunfo and Colima); southern Guatemala (San Jose and Patulul) ; Oaxaca (Santa Efigenia and Tapana); and Guerrero (Acapulco). West to Guerrero (Acapulco, Coyuca, and Chilpancingo); Michoacan (Apatzingan); and rarely Durango (Tamazula).

Spring migration: Early dates of spring arrival are: Georgia: near Roswell, April 11. North Carolina: Waynesville, April 20. Virginia: Blacksburg, March 19 (exceptionally early). West Virginia: White Sulphur Springs, April 19. District of Columbia: Washington, April 20. Pennsylvania: Beaver, April 22. New York: Alfred, April 29. Connecticut: Hadlyme, April 26. Rhode Island: Providence, April 27. Massachusetts: Melrose, April 25. Vermont: St. Johnsbury, April 29. Maine: South Harpswell, April 80. Quebec: East Sherbrooke, May 6. New Brunswick: Scotch Lake, May 8. Nova Scotia: Wolfville, May 4. Louisiana: New Orleans, March 30. Mississippi: Biloxi, April 9. Arkansas: Monticello, April 24. Missouri: St. Louis, April 26. Indiana: Waterloo, April 22. Ohio: Oberlin, April 27. Michigan: Petersburg, April 29. Ontario: Ottawa, May 5. Iowa: Hillsboro, April 24. Minnesota: Lanesboro, April 30. Manitoba: Aweme, May 11. Texas: San Antonio, April 14. Oklahoma: Norman, April 30. Kansas: Lawrence, May 1. Colorado: Yuma, May 13. Nebraska: Falls City, May 2. South Dakota: Sioux Falls, April 30. Wyoming: Torrington, May 5. North Dakota: Fargo, April 21. Montana: lluntley, May 13. Saskatchewan: Indian Head, May 12. Alberta: Red Deer, May 16. Mackenzie: Fort Simpson, May 24.

Fall migration: Late dates of fall departure are: Alberta: Glenevis, September 14. Saskatchewan: Last Mountain Lake, September 3. Montana: Custer County, August 24. North Dakota: Argusville, September 26. Wyoming: Laramie, September 19. South Dakota: Aberdeen, September 22. Nebraska: Omaha, September 24.

Colorado: Holly, September 19. Kansas: Lawrence, September 21. Oklahoma: Kenton, September 26. Texas: Somerset, October 2. Manitoba: Shoal Lake, September 25. Minnesota: Hutchinson, October 8. Iowa: Emmetsburg, October 28. Ontario: Toronto, October 4. Michigan: Detroit, October 14. Ohio-Lakeside, October 13. Indiana: Carlisle, October 12. Missouri: Jasper County, October 20. Kentucky: Bowling Green, October 21. Louisiana: Southwest Reef Light, October 23. New Brunswick: Scotch Lake, September 24. New Hampshire: Jefferson, October 3. Massachusetts: Dennis, October 16. Connecticut: Hartford, October 7. New York: Orient, October 15. New Jersey: Militown, October 1. District of Columbia: Washington, October 1. Virginia: Lexington, September 20. North Carolina: Piney Creek, September 17. Georgia: Athens, October 12.

Casual records: There is an old record (previous to 1884) of the occurrence of the least flycatcher at an elevation of 1,500 feet near Guajango, Peru; one was taken in March 1904 on Grand Cayman Island, between Jamaica and western Cuba; and one was recorded on June 15, 1922, at Ellis Bay, Anticosti Island, Quebec.

Egg dates: Illinois: 12 records, June 4 to 20.

Massachusetts: 35 records, May 26 to June 17; 17 records, June 1 to 9, indicating the height of the season.

New York: 30 records, May 24 to June 27; 16 records, May 24 to June 27.