A rather large, noisy, and colorful flycatcher, the Cassin’s Kingbird is aggressive in defending its nest territory and will mob predatory birds. Cassin’s Kingbirds are migratory in the U.S., although there is a nonmigratory population in Mexico.
The large, bulky nest of the Cassin’s Kingbird is built by the female, and she often includes feathers or flowers around the rim of the nest. Nests are sometimes reused at a later date.
On this page
Description of the Cassin’s Kingbird
The Cassin’s Kingbird is a large flycatcher with a dark gray head and breast, a white malar line, grayish-olive upperparts, and a bright yellow belly.
The sexes are similar.
Seasonal change in appearance
Juveniles are similar, but have pale cinnamon wing edgings.
Cassin’s Kingbirds inhabit open country and open woodlands.
Cassin’s Kingbirds eat insects, and occasionally berries.
Cassin’s Kingbirds forage by observing for flying insects from an exposed perch, and then sallying out to capture them in flight.
Cassin’s Kingbirds breed across much of the southwestern U.S. and in Mexico. They winter primarily in Mexico. The population appears to be stable.
Bent Life History
Visit the Bent Life History for extensive additional information on the Cassin’s Kingbird.
Cassin’s Kingbirds frequently mob hawks and owls.
Female Cassin’s Kingbirds build the nest and incubate the eggs, though both sexes help feed the young.
Calls include a sharp “cha-beer”, while the song consists of a series of nasal “chrr” notes.
- Western Kingbird
Western Kingbirds have paler heads and breasts, and have bold white outer tail edgings.
The Cassin’s Kingbird’s nest is a cup of twigs, weeds, leaves, and hair, is lined with softer materials, and is placed on a horizontal branch of a tree.
Number: Usually lay 3-4 eggs.
Color: Whitish with darker markings.
Incubation and fledging:
The young hatch at about 18 days, and begin to fly in about another 2-3 weeks, though continuing to associate with the adults for some time.
Bent Life History of the Cassin’s Kingbird
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 Cassin’s Kingbird – the common name and sub-species reflect the nomenclature in use at the time the description was written.
TYRANNUS VOCIFERANS SwainsonHABITS
This is another yellow-breasted kingbird, somewhat resembling the Arkansas kingbird and occupying some of the western, and more especially southwestern, range of the latter. The range of vociferaris is not nearly so extensive as that of verticalis, and its local habitat is often quite different. The two species are often found in the same general habitat, especially during the migration periods, but during the breeding season and to a certain extent at other seasons Cassin’s ranges higher in the foothills and the mountains than the Arkansas kingbird. We found Cassin’s kingbirds very common, in April and May, in the lower portions of the canyons, among the large sycamores, in the Catalina and Huachuca Mountains in Arizona. Harry S. Swarth (1904), referring to the Huachucas, says: “I have occasionally, but not often seen the birds as high as 7500 feet, and found one nest quite at the mouth of the canyon, 4500 feet; but as a rule. the territories occupied by this species and verticalis during the breeding season hardly overlap.” The majority of the nest3 he found were between 5000 and 6000 feet. Referring to its range in the Catalinas, W. E. D. Scott (1887) writes: “At the higher Limits of its range in the breeding season: about 9000 feet: it is much more common than 7′. vertu~alis, though the reverse is true as regards the lower limit of its range: about 8500 feet: in the breeding season.” Dr. Alexander Wetmore (1920) says that at Lake Burford, N. Mex., “they frequented rocky hillsides where scattered Yellow Pines rising above the low undergrowth made convenient perches from which to watch for insects and look out over the valleys.”
Henshaw (1875) found it frequenting open country in Arizona and New Mexico, saying, “I have seen it much on the sage brush plains, though never very far from the vicinity of timber; and the sides of open, brushy ravines seem to suit its nature well.”
In California, its distribution is more or less irregular, where it seems to be less of a mountain species than in other places, for W. L. Dawson (1928) says: “Cassin’s Kingbird, at the nesting season, barely exceeds the upper limit of the Lower Sonoran faunal zone; and it is not even mentioned in t.he exhaustive reports on the San Jacinto and San Bernardino mountain regions. It is apparently of very irregular distribution over the two California deserts, and in the lowlands of the San Diego-Santa Barbara region.”
Courtship: The only reference I can find to what might be called a courtship activity is the following observation by Dr. Wetmore (1920) at Lake Burford: “This Kingbird was first observed on May 25 and from then on it was fairly common. * * * Males were seen at intervals in crazy zigzag sky dances made to the accompaniment of harsh calls and odd notes, similar to those of none of our other birds. Toward dusk they called constantly their harsh, stirring notes making a pleasing sound that mingled with the songs of House and Rock Wrens, the scolding of an occasional Mockingbird and the cheerful calls of the Robins.”
Nesting: Major Bendire (1895) writes:
The trees generally selected by this species for nesting sites are pines, oaks, cottonwood, walnut, hackberry, and sycamores, and the nests are almost Invariably placed near the end of a horizontal limb, usually 20 to 40 feet from the ground, In positions where they are not easily reached. All of the nests examined by me were placed In large cottonwoods, with long spreading limbs, and were saddled on one of these, well out toward the extremity. The majority could only be reached by placing a pole against the limb and climbing to it. They are fully as demonstrative as the Arkansas Kingbird when their nests are disturbed, and are equally courageous in the defense of their eggs and young. The nests are large, bulky structures, larger than those of the preceding species, but composed of similar materials. An average nest measures 8 Inches In outer diameter by 3 Inches In depth. The Inner cup Is 3’/2 inches wide by 1% deep. Sometimes they are pretty well concealed to view from below, but they can usually be readily seen at a distance.
Mr. Dawson (1923) noticed, in California, a close association with the Arkansas kingbird:
[In a] region of scattering oak trees and of stream beds lined with cottonwoods, both birds are exceedingly common. As surely as a pair of oak trres boast some degree of isolation from their fellows, one will be occupied by a pair of Cassin Klngblrds and the other by a pair of Westerns. Or if the trees are only members of a series, next door neighbors will be occupied by these paired doubles; and the group may be separated by an Interval of a hundred yards or so from the next quartet. The arrangement Is evidently studied, and It must be mutually agreeable, for the two species are on the best of terms, and I have never seen evidence of jealonsy or ill-will on the part of either, though I have camped right under their nests.
In the Huachuca and Catalina Mountains, the Cassin’s kingbirds showed a preference for the sycamores in the lower canyons, and for the evergreen oaks on the foothills. But near Tombstone, Ariz., my companion, Frank Willard, found a nest 10 feet up in a slender willow and another 8 feet from the ground in a small walnut tree. In California nests have been found in blue-gum trees and in boxelders. Robert B. Rockwell (1908) found nests in Mesa County, Cob., “in scrub-oak, cottonwoods, quaking-asps, and gate frames, on log fences, and on the top of a large farm gate. The birds are of a sociable disposition, nests being rarely found any great distance from human habitation.”
The bulky nests of the Cassin’s kingbird are much like those of the Arkansas kingbird, but will average somewhat larger and rather more firmly built. The foundation and walls are built up with small twigs, rootlets, weed stalks, strips of inner bark and other plant fibers, mixed with bits of string, rags, or dry leaves; the sides and rim are often decorated with feathers, dry blossoms of the sage, or the dry flower clusters of other plants; and the inner cavity is lined with finer rootlets, fine grass, and perhaps a few small feathers; some nests are profusely lined with the cottony seeds of the cottonwood.
One shallow nest that I measured, taken from a sycamore in the Huachuca Mountains, measured externally 184 to 2 inches in height, and 5 to 6 inches in diameter; the inner cavity was 3½ by 4 inches in diameter and 1½ inches deep.
Eggs: Three or four eggs are most commonly laid by Cassin’s kingbird, though quite often the set consists of five and very rarely as few as two. The eggs resemble those of other kingbirds, though they are as a rule less heavily spotted. They are about ovate and are only slightly glossy. The ground color is white or creamy white. The markings, often grouped about the larger end, are small spots or dots of various browns, “chestnut-brown,” “dark vinaceous-brown,” or “light brownish drab,” often, but not always, mixed with underlying spots of “Quaker drab” or shades of pale lavender. The measurements of 50 eggs average 23.5 by 17.4 millimeters; the eggs showing the four extremes measure 27.9 by 19.3, 21.8 by 17.3, and 22.6 by 16.3 millimeters.
Young: Bendire (1895) says that incubation “lasts from twelve to fourteen days, and is almost always, if not exclusively, performed by the female. I have never noticed the male on the nest.” Both sexes, however, assist in the defense and care of the young. Mrs. Wheebock (1904) says that the young remain in the nest about two weeks. In the southern portion of its ranges the Cassin’s kingbird is said to raise two broods in a season.
Plumages: The young kingbirds are hatched naked, but the juvenal plumage soon appears and is well developed, except for the shorter wings and tail, by the time the young bird leaves the nest. The fully developed juvenal plumage is much like that of the adult female, but the plumage is of looser texture and all the colors are duller; the sexes are alike; the head, neck, and breast are a lighter gray, the yellow of the abdomen is paler, and the back is more grayish brown; there is no orange-red crown patch; the paler markings on the wings are tinged with buff, and the outer primaries are not attenuated; the tail feathers are somewhat shorter than in the adult, and are narrowly tipped with browm This plumage is worn through the summer, until an apparently complete postjuvenal molt, mainly in September, produces a first winter plumage, like that of the adult, but slightly paler and still lacking the crown patch. In this first winter plumage the young male acquires the attenuated outer primaries as in the adult; adult males have four or five of the outer primaries sharply attenuated; in adult females these feathers are only bluntly pointed, if at all so. In the first winter tail the feathers are tipped with yellowish gray, or whitish, and more broadly than in the younger bird. Apparently there is a partial prenuptial molt early in spring, at which the orange-red crown patch is acquired. Adults apparently molt at the same times and in the same manner as the young birds; June and July adults show considerable wear.
Food: Living in much of the territory occupied by the Arkansas kingbird and foraging in much the same manner, the food of Cassin’s kingbird is almost identical with that of the better-known species. Professor Beal (1912) examined only 40 stomachs of Cassin’s kingbird, in which the food was “found to be composed of 78.57 per cent of animal matter to 21.43 of vegetable.” Of the animal food: beetles of all kinds amount to 14.91 per cent of the food. Of these, about 1 per cent are of species that are more or less useful (Carabidae). Hymenoptera amount to 21.61 per cent and consist for the most part of wild bees and wasps. No honeybees were found, but several predaceous or parasitic species were identified. * Lepidoptera, I. e., moths and caterpillars. amount to 18.21 per cent of the food, which is a high percentage for a flycatcher; for while moths may be caught on the wing, caterpillars must be picked from the surface on which they crawl, unless they let themselves down from a tree by a thread and so hang in mid-air. * Orthoptera (grasshoppers and crickets) are apparently eaten rather irregularly, but as nearly every month in which they appeared at all showed a goodly quantity, they would seem to be a favorite food, and it Is probable that a greater number of stomachs would give a more regular showing. In January they amount to 47.50 per cent in 4 stomachs, while the 1 stomach taken in February shows none at alL * The total for the year is 14.67.”
Small percentages of Hemiptera (bugs), Diptera (flies), a few dragonflies, and some spiders make up the balance of the animal food, 9.17 percent.
Of the vegetable food, Professor Beal (1912) says: “Mthough Cassin’s kingbird eats more vegetable food than any other flycatcher, there is very little variety to it. Grapes, apparently of cultivated varieties, were found in 9 stomachs, olives in 2, elderberries in 1, blueberries (Vaccinium) in 1, and pulp not further identified in 4. With the exception of some grapes found in 1 of the March stomachs, all the fruit was eaten in the months from September to January, inclusive.”
Behavior: Henshaw (1875) quotes some Colorado notes from C. E. Aiken, which give a good idea of the behavior and appearance of Cassin’s kingbird as compared with the Arkansas kingbird; he writes:
Although these two birds resemble each other so closely In the skin, In life there are marked differences in notes and actions that even a novice cannot fail to notice. Vcrticalig is a nervous, fickle creature, seldom remaining long in one place, and flying with a quick fluttering motion of the wings. It Is also exceedingly noisy, its notes being a high pitched chatter. Vociferans, on the other hand, is a more matter of fact bird, often sitting quietly for a long time in the same place, and its notes are harsher and less frequently uttered. Its appearance, too, when alive conveys the impression of a heavier, stouter built bird. When migrating, and indeed at other times, It appears to be restricted to the parks of the foothills, alighting upon weed stalks and low bushes, from which It sallies forth occasionally to seize some passing insect.
Henshaw (1875) also says: “Though found in the same locality, individua]s of the two species never meet without displaying their natural enmity. At Camp Grant, my attention being called by the loud outcries of several of these birds, I found that a female and several young of the Arkansas Flycatcher were the objects of a savage assault by a pair of the present species. The mother bird most gallantly stood up and fought for her offspring, repelling each attack with a brave front, and retaliating to the best of her ability. I watched them until I saw that the assailants, having fairly got. worsted, were glad to retire, and leave the family to gather together in peace.”
This behavior is quite different from that noted by Mr. Dawson (1923) in California, referred to under nesting; evidently there is considerable individual variation in behavior in this, as in many other species. Some observers state that this kingbird does not persecute hawks and crows so Inuch as the other kingbirds do. but others report to the contrary. For example, E. A. Mearns (1890) says: “On the Mogollon Mountains I saw them attack Crows and Western Red-tailed Hawks and drive them from the neighborhood of their nests after the spirited fashion of the Eastern Kingbird.” Doubtless all kingbirds would do this. Florence A. Merriam Bailey (1896) writes: “Mr. Merriam told me that when he was plowing and the Blackbirds were following him, two or three of the ‘Beebirds,’ as he called them, would take up positions on stakes overlooking the flock; and when one of the Blackbirds got a worm that he could not gulp right down, a Beebird would dart after him and fight for it, chasing the Blackbird till he got it away. For the time the Flycatchers regularly made their living off the Blackbirds as the Eagles do from the Fish Hawks.”
Voice: Mr. Dawson (1923) writes: “Cassin’s Kingbird says, (Ike bew’, in a heavy, grumpy tone, whose last flick nevertheless cuts like a whi p-i ash: c hebe et~. This is generically similar, but specifically very different from the evenly accented, and more nearly placid ber’ wick of the Western Kingbird. The note of greeting or of general alarm in Cassin is a breathless ku~A da~ kuk da~ kuhda~?; or, as I heard a~ female render it, kiddoi~5 kiddo~ kiddo6 kiddo6 kidduck. For the rest Cassin is a rather more sober and a much more silent bird than is the volatile ‘verticali8.”
Ralph Hoffmann (1927) says that “its common call is a harsh, lowpitched ckerr, followed by a ke-d4ar, which suggests the Ash-throated Flycatcher. In the breeding season it utters a series of high, petulant notes, ki-dee-dee-dee.” Mr. Swarth (1904) writes: “Commencing shortly before daybreak, they keep up a continuous clamor, generally on the wooded hillsides, to such an extent that it seems like an army of birds engaged. They do not seem to be quarreling or fighting at these times, for those I have seen merely sat, screaming, on the top of some tall tree. This racket is kept up until about sunrise, when it drops rather abruptly.” About our camp in picturesque Apache Canyon in the Catalina Mountains, Ariz., we found Cassin’s kingbirds very common; they greeted us every morning with their rather melodious notes, as they flitted about in the tops of the grand old sycamores and cottonwoods; they seemed to say “come here, come here,” in rather pleasing tones, as their voices mingled with the rich song of the Arizona cardinal and the attractive notes of the canyon wren, the Arizona hooded oriole, the canyon towhee, and the host of other birds that made our mornings in that beautiful canyon so delightful.
Field mark8: Cassin’s kingbird bears a superficial resemblance to both Couch’s kingbird and the Arkansas kingbird. Where its range overlaps that of the western races of melanokolicus, Cassin’s can be recognized by having a blacker tail and the conspicuous white space on the chin and throat more restricted and more sharply defined against the gray of the chest; the yellow of the under parts is also paler. From the Arkansas kingbird it can be distinguished by the darker gray of the head, neck, and chest, sharply contrasted with the white throat, by the lack of the white outer web of the outer tail feather, and by the white tips of the tail feathers. Moreover, its voice, its apparently heavier build, and its general behavior, as indicated above, should make it easier to recognize Cassin’s kingbird in life than in a museum specimen.
Range: Western United States and Central America south to Guatemala.
Breeding range: Cassin’s kingbird breeds north to central California (Redwood City and probably Tracy); northern Utah (Salt Lake County); and northern Colorado (probably Ault). East to eastern Colorado (probably Ault, Agate, and Beulah); western Oklahoma (Kenton); eastern New Mexico (Montoya and Roswell) ; western Texas (Fort Davis and Alpine); western Tamaulipas (Miquihuana); and Guerrero (Chulpancingo). South to Guerrero (Chilpancingo); Jalisco (Ocotlan); southwestern Durango (Salto); and northern Baja California (Aguaita). West to northwestern Baja California (Aguaita and San Quintin); and north along the coast of California to Redwood City.
Winter range: During the winter months these birds are found north to southern California (Santa Barbara and Salton Sea) ; southern Arizona (Nogales); and Chihuahua (Colonia Garcia and Chihuahua City); and south through Mexico (chiefly the western part), to Guatemala (Salama and Duenas).
Spring migration: Early dates of spring arrival are: New Mexico: State College, April 13. Colorado: Pueblo, April 29. Arizona: Tucson, March 24. Utah: Salt Lake City, May 11. Central California: Paicines, March 7.
Fall migration: Late dates of fall departure are: Central California: San Francisco, October 22. Arizona: Tombstone, November 1; Tucson, November 10. Colorado: Beulah, September 5. New Mexico: Mesilla, October 12.
Casual records: In common with many other flycatchers, Cassin’s kingbird has been taken or observed on several occasions at points outside its normal range. Records in southeastern Wyoming (Douglas, Laramie Peak, Laramie, Cheyenne, and Albany County) indicate the probability of breeding in that area. In the Bull Mountains, Mont., several were seen and specimens taken on August 5 and 6, 1918; one was reported at Beaverton, Oreg., on May 5, 1885, and a pair were recorded from the Warner Valley in that State on June 10, 1922.
Egg dates: Arizona: 21 records, May 3 to August 1; 11 records, May 28 to June 22, indicating the height of the season.
California: 72 records, April 22 to June 29; 36 records, May 11 to June 2. Lower California: 8 records, May 13 to June 18. New Mexico: 8 records, May 4 to June 29.