Bendire’s Thrasher

Photograph © Tom Grey

The Bendire’s Thrasher has grayish-brown upperparts, a long tail, a relatively short and slightly decurved bill, pale creamy underparts indistinctly marked with small triangles, and yellowish eyes.

The sexes are similar.

None.

Juveniles have fewer markings below.

Bendire’s Thrashers inhabit farmland, deserts, and thorny scrub.

Bendire’s Thrashers eat insects and a few seeds and berries.

Bendire’s Thrashers forage primarily on the ground.

Bendire’s Thrashers breed in the southwestern U.S. and Mexico, and winter primarily in Mexico, though a few are resident in southeastern Arizona.

Major Charles Bendire first named this species, the last thrasher to be described to science in North America,

Grasshoppers, ants, and termites are among the favored prey of Bendire’s Thrashers.

Calls include a “chuk” sound, while the song is a series of harsh, warbling phrases.

The Bendire’s Thrasher’s nest is a cup of twigs lined with finer materials, and is placed low in dense, thorny vegetation.

Bendire’s Thrashers usually lay 3 eggs, whitish in color with darker markings.

Incubation and fledging
The young hatch at an unknown age, and leave the nest in about another 12 days, though continuing to associate 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 Bendire’s Thrasher – the common name and sub-species reflect the nomenclature in use at the time the description was written.

Bendire’s is one of several species of thrashers that breed in our southwestern deserts. The Southwest is rich in species and subspecies of this genus, but they all occupy rather limited ranges, as compared with our wide-ranging and homogeneous brown thrasher. Bendire’s thrasher is one of the most limited in its range, breeding only in southeastern California, Arizona, southwestern New Mexico, and northern Sonora. And, according to my experience, it is not very common anywhere, except perhaps in the low, fiat country around Tucson and the foothills of the southern Catalinas. It has been reported as locally common in the Lower Sonoran valleys in other parts of Arizona and western New Mexico and in some places up to 4,000 or even 6,500 feet in the mountains. There are scattering records from northeastern and northwestern Arizona.

Spring: W. E. D. Scott (1888a) writes: “On the plains about Tucson and to the southward, this species is resident, but even here there seems to be a very considerable migration, as the birds are much more common in the spring and during the breeding season than during the late fall and winter months. * * *

“In the foothills of the Catalinas the birds were not resident but were present for about 8 months of the year, and were quite common during the breeding season, though they did not range above 4,000 feet. Here they arrive early in March, the 7th of that month being the earliest record made, and begin mating and nesting almost at once.”

Herbert Brown (1901) says: “During the winter months an occasional one can be found in their usual habitat, but, as a whole, they go south bodily on the first fall storm of wind and rain. The return migration is more gradual, but always of uncertain date. I have known the difference of a full month to exist in their homecoming in two succeeding years. This was probably due to climatic conditions further south.” He gives February 9 as the earliest known date of arrival, when “they were gathered in small flocks and were not mated.”

Nesting: 0ur experience with the nesting of Bendire’s thrasher in Cochise and Pima Counties, Ariz., was limited to three nests, one found April 26, 1922, with young, and two, found on May 23 and June 11, with eggs. So I prefer to quote from some of the excellent accounts that have been published. Herbert Brown (1901) gives the fullest account; he says: “The first week in March will frequently find them nesting, and the middle of April preparations for a second brood are well under way, but, taken over a long series of years, the beginning of April generally sees them busy with their first house making. I have never been able to fully determine the exact number of families raised by one pair of birds during a season. Of two there can be no question, but a third is in doubt, although I have known the nesting season to last three full months and a half. To be more exact, February 24 is the earliest and July 18 the latest I have in mind for 1 year.

He has measured at least 200 nests and gives these measurements and other data on 17 of them; the highest of these, there recorded, was about 12 feet from the ground in a mesquite; of the others, in tasajas and chollas, two were 5 feet, one only 22 inches, and the remainder between 3 and 4 feet above the ground; the measurements of these 17 nests varied greatly; the diameter of the nest proper was 6 to 7 inches, but as much as 11 or 12 inches over-all, including the foundation twigs; the inside diameter varied 2¼ to 3½ inches, the inside depth 1½ to 3½, and the over-all depth 3 to 9 inches. He observed that —

the larger portion of the nests are in tasajas. This is a species of cactus for which, for the want of a better name, I am obliged to use that of the Mexicans. The word means “dry or jerked beef” which in color and shape the tasaja somewhat resembles. The spines, although innumberable, are short and the branches spreading and open. The cholla is the characteristic cactus of the desert. It is a mass of barbed spines and is the favorite nesting place of H. palmeri, but not of H. bendirei. Taking 50 nests in succession 34 of them were placed in tasajas, 11 in chollas, 3 in tesota bushes, 1 in a mesquite tree and one in a willow tree. These results are from the Fort Lowell district. In other sections of country less characteristic of the cacti I have found them largely inclined to tree nesting, but never at any great height from the ground. This was Capt. Bendire’s experience also. The highest I ever saw one placed was in a willow about 20 feet up. I also saw one in a tasaja the bottom of which was not more than 6 inches from the ground. * * *

The nest is small and daintily constructed by comparison with those of other thrashers. It is less compactly built than that of H. palmeri, but the manner of construction is common to all Arizona thrashers. There is an external nest of sticks, few or many, the nest proper of grass and lined with any soft material conveniently obtainable.

M. French Gilman (1909) has published a comprehensive paper on the thrashers of Arizona, in which he says of this species:

A great range in choice of nesting sites was noticed. Of the thirty-nine nests, thirteen were in Lycium bushes; three in mistletoe, in mesquite and catsclaw (Acacia greggii); three in palo verde, two in catsclaw, two in Sarcobatus, one in screw-bean, and one in a salt-bush. The average height was 5 feet, and the extremes 3 feet and 10 feet. Two nests, deserted as far as the thrashers were concerned, were found, each containing an egg of Gambel Partridge. * * *

The nests are much finer in material and workbirdship than those of most thrashers. They are smaller, more compactly built and very symmetrical in their cupped shape. Finer twigs are used in the outside and they are fitted closely together. The lining is variously composed of horse-hair, thread, twine, pieces of cloth, grass, weeds, rootlets, fine bark, wool and cotton from bed-quilts, etc., etc. Most of them contain more or less horsehair, and if near an Indian home, as is often the case, twine and material from the bed covers enters largely into the lining. One nest I noticed was built against a Verdin’s nest, the wall of the latter in fact forming part of one side of the thrasher’s nest. Both nests contained eggs, so the proprietors were on very neighborly terms, even tho I could discover no doorway between the apartments.

F. W. Braund has sent me the data on a nest he found near Tucson on May 7, 1935, that was lined with creosote blooms, weed stems, and seed pods.

Dr. Friedmann (1934) mentions only one case where Bendire’s thrasher has been a host to the dwarf cowbird.

Eggs: Mr. Brown (1901) has seen so many eggs of Bendire’s thrasher, that I cannot do better than to quote his full description of them as follows:

With rare exceptions four eggs are the maximum number laid. I have examined probably 500 nests, two only of which contained more. They bad five eggs each. Four is not an unusual number, but three is a normal set. * * *

The ground color in the majority of the 148 specimens varies from a pale gray green to a greenish white, the former predominating. In a single set it is a clear pale green with a bluish tinge. Most of the eggs are irregularly spotted and blotched with well-defined markings of tawny ecru drab, fawn color and vinaceous buff. These markings are generally heaviest about the larger end of the egg; In some specimens the spots run longitudinally. In this type about three-fourths of the eggs examined can be included. They resemble, in the style of marking, the eggs of Mimus polyglottos, somewhat, although the eggs themselves look quite different. In about 20 percent the ground color is somewhat clouded over and partially obscured by the markings, which are finer, less pronounced, giving the egg a uniform pearl gray and pale greenish gray appearance till closely looked at. In an occasional specimen, the markings are simply fine pinpoints, as in the smaller spotted eggs of Harporhynchus rufus.

In about 5 percent of the eggs, the ground color is grayish or pinkish white with scarcely a trace of green, and the egg Is heavily and uniformly spotted with longitudinal markings of pale salmon color and lavender, bearing a striking resemblance to some eggs of Myiadestes townsendi, excepting in size. A single egg has a distinct wreath about the larger end.

The shape of these eggs varies a great deal, the most common form being an elongate ovate, varying from this to ovate, short ovate, and elliptical ovate.

The measurements of 50 eggs in the United States National Museum average 25.6 by 19.1 millimeters; the eggs showing the four extremes measure 29.7 by 19.6, 28.5 by 21.8, 23.4 by 18.8, and 25.4 by 17.8 millimeters.

Young: No one seems to have determined the period of incubation for this thrasher or the length of time that the young remain in the nest, though Bendire’s probably does not differ materially from other desert thrashers in these matters. This species is so shy about its nest that the care and feeding of the young are not easily observed, and nothing seems to have been recorded on this subject. As mentioned above, two broods in a season seems to be the rule, with sometimes a third brood. Mr. Gilman (1915) noted that one pair of birds brought off a brood of young about the first of May, a second brood left the nest on July 6, and on July 25 the female was incubating on a third set of eggs.

Mr. Scott (1888a) says: “The young birds, as soon as they are fully grown, begin to congregate in companies, often being associated with one or two H. curvirostris palmeri and H. crissalis. I have seen forty or fifty young Thrashers, mostly bendirei, together in such a flock in late May and early June. At such times the birds seek a somewhat higher altitude, as high as five thousand feet, and effect thickets of low oaks and juniper.”

Plumages: Young Bendire’s thrashers in juvenal plumage differ from the breeding adults, which are then quite worn and faded, in having the upper parts, especially the rump, tinged with reddish brown, the secondaries and tertials broadly edged and tipped with buffy brown, the greater wing coverts broadly tipped with “cinnamon-buff,” and the tail feathers (except the central pair) tipped with buffy brown. In very young birds the underparts are more or less tinged with “cinnamon-buff,” most strongly on the flanks and crissum, which fades out to dull white in older birds; there is much individual variation in the amount and distribution of the grayish brown spots or streaks on the under parts; in some these markings cover all the breast and abdomen, while in others they are confined to the breast or only to the sides.

The time at which the postjuvenal molt takes place varies with the dates on which the two broods were hatched, but a partial molt, involving the contour plumage and the wing coverts, produces a first-winter plumage practically indistinguishable from that of the fall adult.

Adults have a complete postnuptial molt, beginning late in July and continuing through August. Adults in fresh fall plumage are darker and grayer above and the spots on the chest are darker than in spring birds; wear and fading produce paler spotting on the underparts, the spots becoming faint in many cases before summer.

Food: No very comprehensive study of the food of Bendire’s thrasher seems to have been made and very little has appeared in print about it~ Like other thrashers, it evidently lives largely on insects, such as beetles, caterpillars, and other larvae and pupae, which it obtains mainly on or near the ground. William L. Engels (1940) says: “The Bendire thrasher, like the brown, spends much time on the ground while foraging. Near Coolidge, Arizona, one was watched from an automobile as it searched for food on the shoulder of the road, hammering vigorously at the ground with its relatively short, slightly curved bill. Another, seen in a cultivated field beside a patch of mesquite in which its nest was situated, was running along between plant rows, occasionally jumping up into the air as if catching insects.” Two that he shot, a pair coming to their nest, were “found to be carrying small, green, wormlike larvae.”

Behavior: Mr. Scott (1888a) regarded this thrasher as “at all times shy and wary and difficult to approach, even when nesting.” But Mr. Gilman (1915) says: “The Bendire Thrasher is one bird that from all indications takes kindly to settlement. These birds nest near houses, on which they perch to sing, come into the yards, and seem fearless if not molested. If their natural shelter is cleared up they take kindly to artificial or planted growth and I believe will persist in the face of civilization. All this of course, provided that they receive some measure of protection and encouragement.”

Mr. Engels (1940) gives us some information on the general behavior of this thrasher on the ground and in the air. One that he watched on a creosote-bush fiat was followed for several hundred yards:

It walked or ran along, now slowly, now rapidly, in and out among the creosote bushes, sometimes flying up into a low bush, then directly down again to the ground. Gait and carriage in these birds were essentially as In the brown thrasher.

Most Bendire thrashers seen, when not perched, were moving on the wing in smooth easy flight. A. H. Miller (MS field notes, 1936) finds their flight remindful of that of mockingbirds. Flight is their usual method of locomotion; time and again they were seen flying from tree to tree at heights of from 25 to 50 feet, and, once, for a distance of more than a quarter-mile. This behavior was especially noticeable when the bird was being pursued; before I could maneuver myself into shotgun range, the bird would fly off to some more distant perch. A bird suddenly approached, while on the ground, flew directly up Into the top of an adjacent mesquite about 30 feet high.

Voice: Like all the thrashers, Bendire’s is no mean singer; it is almost equal to the brown thrasher and suggestive of even the mockingbird. Mr. Gilman (1909) praises it in the following words:

As for singing, the Bendire has them all beaten. The others are fine singers indeed, but their repertoire is limited. Not so with Bendire. No two seem to sing exactly alike and some of the songs are quite distinct from others. Not only in variety of notes but in arrangement, are differences noticed. He is a more constant singer than the others and I frequently discovered a nest by the song of the bird. The earliest date of singing was January 3, and I could hardly believe at first that Bendire was the performer. It was a low warbling song with a decided sparrow “burr” to it. I approached as near as the bird would allow, but could not be sure that he was the singer as no throat movement could be detected. When the bird flew, the song ceased and began again after he perched on a post. I repeated this maneuver several times before I was convinced that Bendire was warbling. Next evening I walked under a mesquite tree containing the singer and obtained a good close view of him and his performance.

As the breeding season approached they sang more often, the song becoming louder and with less of the burr, in fact more like the typical thrasher song, if such there be. The songs were all very pleasing, but the variations were often puzzling at first. Whenever I heard a new strain I said, “only another Bendire tuning up.” They kept up the music till late In June and occasionally a song could be heard all summer and up to the last of September.

Field marks: Bendire’s might easily be confused with Palmer’s thrasher in the field, but the former is browner above, the spots on the chest are smaller and more distinct, and there is more white on the tail tips. Mr. Gilman (1909) says that Bendire’s has a smoother, evener flight than the somewhat jerky flight of Palmer’s thrasher. Bendire’s can be distinguished easily from the crissal and LeConte’s thrashers by its comparatively short, straight bill and by the grayish-brown spots on its breast; the latter two have much longer, curved bills and unspotted breasts.

Winter: Authorities seem to differ as to the extent of the migration and the winter range of Bendire’s thrasher. Probably there is usually a short migration in fall from most of the range of the species. Some individuals evidently remain on or near their breeding grounds all winter, but they seem to be very scarce or entirely absent from many of their summer haunts at that season. Their migration route is not long, and they are absent for only a short period late in fall and early in winter. Their winter range extends only as far south as southern Sinaloa.

DISTRIBUTION

Range: Southwestern United States and northwestern Mexico.

Breeding range: The Bendire’s thrasher breeds north to southern California (Victorville, Cima, and Rock Spring); central and northeastern Arizona (Beale Spring, Klethia Valley, Navajo County, and Chin Lee). East to northeastern Arizona (Chin Lee and St. Michaels); extreme western New Mexico (Catron County, 25 miles east of Springerville, Arizona, and Rodeo, Hidalgo County); and northwestern Chihuahua (Sierra Carrizalillo). South to northwestern Chihuahua (Sierra Carrizalillo); and central Sonora (Tecoripa and Guaymas). West to western Sonora (Guaymas, Artiz, and Santa Ana); Arizona (Menager’s Dam, Gunsight, Gilabend, and Congress Junction); and southern California (Palm Springs and Victorville).

Winter range: The winter range of the Bendire’s thrasher cannot be exactly defined on the basis of available records. It withdraws from the northern part of its range, but is resident in southern Arizona, probably north about to the Gila River (the northernmost winter record is Phoenix). It moves southward to southern Sonora (Camoa, Tesia, and Alamos) and to southern Sinaloa (Escuinapa).

Casual records: In a suburb of Los Angeles, Calif., an individual was picked up on September 10, 1912. The only record for Nevada is of two individuals seen and one collected on May 16, 1939, near Delmar, Lincoln County. There are three records for Utah; a nest and eggs from the shore of Utah Lake south of Lehi on April 26, 1932; a single bird seen and collected 10 miles southeast of Escalente, Garfield County, on May 9, 1937; and two specimens collected and other birds seen on July 4, 1927, in Monument Valley where they may be of regular occurrence. A specimen was collected in El Paso County, Cob., at Austins Bluffs, on May 8, 1882.

Egg dates: Arizona: 143 records, February 24 to August 1; 76 records, March 16 to April 15, indicating the height of the season.