Bent Life History of the Crissal Thrasher

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 Crissal Thrasher - the common name and sub-species reflect the nomenclature in use at the time the description was written.

 

CRISSAL THRASHER
TOXOSTOMA DORSALE DORSALE Henry

HABITS


Although the range of the crissal thrasher coincides in a very general way with much of the ranges of the three other desert thrashers, its haunts and chosen habitats are quite different from those of the others, and they seldom overlap to any extent. LeConte's thrasher lives in the hottest, driest, and most open deserts; Bendire's and the curve-billed thrashers are found on the slightly more fertile deserts and valleys, where there is more vegetation, and about the ranches; but the crissal thrasher seldom ventures out onto the desert and prefers the more fertile valleys, canyons, and hillsides, where it can hide among the more abundant vegetation and in the dense thickets, often in the vicinity of water.

What few crissal thrashers we saw in southern Arizona were found in the belts of small mesquites, creosote hushes, and sagebrush that grew along the arroyos, in low bushy underbrush in the valleys, in the willows along a ditch in the San Pedro Valley, and on the rough sides of the Dragoon Mountains, where mesquites, junipers, and straggling bushes grew among the rocks. They were not very common and were always shy and retiring.

Frank Stephens told Mr. Brewster (1882a) that "he found the Crissal Thrasher in copses in valleys, and along streams. It was especially fond of well-shaded undergrowth, and spent much of its time on the ground, searching for food under the bushes. It never occurred among cactuses, and the only place where he saw it actually associating with Bendire's and Palmer's Thrashers, was at Camp Lowell, where the latter species, with other desert birds, came to drink at a water-hole and thus occasionally mingled with the Crissal Thrashers, which inhabited the neighboring thickets."

M. French Gilman (1902) says that, on the California side of the Colorado River, "great numbers of them can be found in the dense thickets of mesquite and screw-bean in the depressed portion of the desert near the Salton sink," which is from 10 to 260 feet below sea level.

Nesting: We found only two nests of the crissal thrasher in southeastern Arizona in 1922. Near Fairbank, in the San Pedro Valley, on May 27, a nest containing one egg was seen about 8 feet above ground in a vine-covered willow in a row of these trees growing along an irrigation ditch. The other nest, found on June 1 near Tombstone, was placed 3 feet from the ground in a dense sagebush on the edge of an arroyo, where it was well hidden; it was made of thorny twigs with a lining of fine bluish fiber; it held three eggs.

Dean Amadon (MS.) reports a nest, found near Tucson on June 24, 1938, that was placed on a branch of a willow next to the trunk and about 8 feet above ground; this was near a ditch leading away from a pond in a brushy area; at that date it contained one young bird, perhaps a week old, and two unhatched eggs. A set of two eggs in the F. W. Braund collection, taken near Phoenix on March 17, 1896, came from a nest in a catsclaw bush on the desert.

A nest found by Dr. Mearns (1886) near Fort Verde, Ariz., on February 18, 1886, was described as follows: "The nest was saddled upon the fork of a mesquite-bush, about 4 feet from the ground, in part supported by the thorny branches of a neighboring bush. It rested upon a pile of sticks, and was surrounded by a bristling array of spiny 'haw' and mesquite twigs of moderate size; within this barricade the nest proper was placed; it is bowl-shaped, and, with the exception of a few feathers, composed entirely of vegetable substances very neatly felted into a compact, warm nest. The principal materials are fine withered grass, stems of plants, and shreddy inner bark. Externally it measures 150 mm. in height by 300 mm. in width; the internal depth, 45 mm.; internal diameter, 90 mm."

Mr. Gilman (1902) writes of the nests found in the Colorado desert:

On March 18 and 19 we found 10 nests containing eggs or young. With one exception they were all built close up to an over-hanging limb making it difficult to insert the hand. All but one were also in the densest part of the mesquite and rather hard to see. And hard to get at too as anyone who has crawled through a mesquite thicket can testify. The nests were from 2½ to 6 feet from the ground—the average being about 3½ feet and only one 6 feet. * * * From brief observation I should say that individual birds nest near the same spot year after year. Nearly every nest found was near from one to three old nests, probably belonging to the same bird as no new nests were ever found close to each other. In one case three nests were found in the same tree: one new and two old ones.

Nests have also been found in other bushes, such as atriplex, greasewood, wild currant, and ironwood, but never, I believe, in cactus; and they are generally in thick bushes and well concealed. Mr. Gilman (1909) says of the many nests he has noted, 27 were in mesquites, "one was on top of a stump but hidden by dense, sprouting twigs. Eleven were in 'squawberry' bushes, four in greasewood, one in a palo verde, one in a mistletoe, and one in a low brush fence.

Eggs: The complete set of eggs for the crissal thrasher may consist of two, three, or four, most commonly two or three. These vary from ovate to elliptical-ovate and have very little gloss. They look much like robin's eggs, darker and greener when fresh in the nest and fading to paler shades of bluish green or greenish blue when older. Eggs that I have seen in the cabinet are usually a pale shade of robin's egg blue, "pale Nile blue," or "beryl blue." They differ from all other thrashers' eggs in being entirely unmarked. The measurements of 50 eggs in the United States National Museum average 26.8 by 19.2 millimeters; the eggs showing the four extremes measure 30.5 by 19.8, 28.5 by 20.8, 24.3 by 19.7 and 25.9 by 17.8 millimeters.

Young: Both sexes share the duties of incubation and care of the young. The long breeding season, from February to June or July, indicates that at least two broods are reared in a season. Mr. Gilman (1909) watched a nest from the time that the two eggs were laid until the young birds left the nest, a nesting period of 30 days. "The set was completed April 6. At 6 a.m., April 20, one young was just out of the shell and the other egg pipped. At 6 p.m., the same date, both young were opening their mouths and trying to swallow my finger. No eggshell could be found. May 6th both young birds left the nest."

Mrs. Wheelock (1904) writes: "The young Thrashers hatch in 14 days. They are naked, except for the faintest suggestion of down on head and back, and are fed by regurgitation until four days old. On the ninth day the young are feathered all but the wings and tail, which still wear their sheaths, and the featherless tracts which are on all young birds. The iris of the eye is white at this time, but gradually becomes straw-color like that of the adult. Unless startled into an earlier exit, the Thrasher nestlings do not leave the cradle until 11 or 12 days old, and even then they hide in the bushes for many ensuing days, helplessly waiting to be fed by the adult."

Plumages: Young crissal thrashers in juvenal plumage are very similar to the adults in spring plumage but browner throughout, the rich chestnut-brown of the under tail coverts being only slightly duller; the rump and the broad tipping on the tail are brownish chestnut; the bill is shorter and smaller, and the plumage is softer and looser.

After the postjuvenal molt, which involves the contour plumage but not the wings and tail, the young bird becomes indistinguishable from the adult in fall plumage; the date of this molt probably varies with the date on which the young bird was hatched. Adults have a complete postnuptial molt during July and August; the fresh fall plumage is slightly darker and grayer than the faded spring plumage. The sexes are practically alike in all plumages.

Food: Very little seems to have been published on the food of this bird. Dr. Mearns (1886) says that it is "omnivorous. It feeds largely upon berries and wild grapes. A thorny species of 'haw' is plentiful along the Rio Verde, which bears an abundance of berries, of green, red, and dark glaucous-blue colors, according to the degree of maturity; upon these the Thrashers delight to feed. Insects constitute an important article of their diet at all seasons.”

It is said to eat juniper berries and other wild fruits. The stomach of one of the birds collected for Mr. Brewster (1882a) "contained insects and a small lizard."

Behavior: The crissal thrasher is a shy, retiring bird: all one usually sees of it is a fleeting glimpse as it darts away skillfully into or under the brushy thickets. William L. Engels (1940) says that they are much like the California thrasher in their behavior:

They prefer, likewise, dense and Continuous cover, such as that afforded by mesquite thickets, to which they are almost exclusively restricted, as the California thrasher is to the chaparral. Beneath the cover of the dense mesquite they move quickly along, in and out, with long, graceful strides, head forward, tail high, stopping here and there to dig or to whisk the litter aside In search of food. They are likewise agile in scrambling about in the thorny trees, working their way up toward the tops, the favored singing posts.

Crissal thrashers, too, are little given to flight. In the field, one's most common sight of them is a sudden, brief glimpse of a bird abruptly dropping from a bushtop to the ground in a short swoop, wings outspread. Pursued, they make off rapidly on the ground, turning and twisting among the hushes, only occasionally taking to wing. Sometimes one may fly for 20 to 30 yards. One of the few crissals I saw In flight is thus described in my field notes: ". . . its long tall held straight out behind, the head extended forward, it would make a few rapid wingbeats; then with outstretched wings, which looked ridiculously short, it would sail on, only for a few feet, and then repeat."

Mrs. Bailey (1928) says that, "when tempted by water, the thicket-loving bird may come to drink with the chickens and dig in the garden, the strong pickaxe bill and large feet characteristic of the Thrashers making effective implements." Mrs. Wheelock (1904) also refers to his fondness for water, saying: "Rarely will you find him nesting at any great distance from water, and one of the first lessons he gives his brood is to take a morning splash. It is well worth rising at 4 a.m. to see him plunge so eagerly into the cold water and splash it in a shower of sparkling drops. The bath over, he flies up to the top of a tall bush to preen his wet feathers and fill the air with melody."

Voice: Like most of the other thrashers, the crissal is a gifted songster. Dr. Mearns (1886) pays the following tribute to its music:

One of the first traits that we noticed about it was that it possessed a song of very remarkable scope and sweetness, having all the power of the Mockingbird, and an evenness and perfect modulation which that bird may well envy. It is one of the few birds that truly sing; and it shares, in this Territory, this rare gift with its three congeners—Bendire's, Palmer's and LeConte's Thrashers. It is no warbler of pretty ditties, nor yet a medley singer like the Eastern Thrasher or the Mockingbird, but discourses pure, natural music from the top of the tallest bushes, where it perches, with its tail hanging down, in precisely the same attitude as the Brown Thrasher of the East. Its season of song is more protracted than that of any other species with which I am familiar. Its best efforts are put forth during the mating season, in February, March, and April; but, except during July and August, when the heat becomes intense and the Thrasher's plumage is bleached almost to whiteness, and worn to tattered shreds amongst the thorny chaparral in which it finds food and some shelter from the sun, it sings commonly throughout the year. The warm sunshine of a winter's day suffices to bring out its full song, which perchance has been hushed by a cold snap and flurry of snow. At first come a few notes of doubtful confidence, barely sufficing to remind one that it can sing; then a thoughtful, somewhat desultory song, till the power of the tropical sun asserts itself, or the genial influence of its mate is felt, when the harmonious soliloquy grows into a serene and dignified performance that challenges attention and excites admiration. The Crissal Thrasher is a shy bird, and only sings when it fancies itself secure from intrusions upon its solitude; but, about ranches, where it associates with man, it loses some of its wildness and becomes more confident and trusting.

After the autumnal moult, when berries, grapes, and other acceptable food Is plentiful, there is a distinct revival of song in this species. It has no loud call-note like the other species.

Mrs. Wheelock (1904) remarks that "every note is sweet, true, and perfect, but the whole lacks the spasmodic brilliancy we are accustomed to expect in his family. It has a more spiritual quality but less dash."

Mrs. Bailey (1928) mentions "its call notes 'queety-queety' and a scolding 'cha.'" W. L. Dawson (1923) refers to "a solicitous note, pichoory, pitchoory, or pitchree' "; also, "one very earnest fowl, near Tucson, remarked, Pichoori karrik', pichoori karrik' in quite a brisk manner."

Field marks: The crissal thrasher was formerly called the red-vented thrasher, on account of the deep reddish brown of the under tail coverts and crissum, from which, also, the name crissal was derived. This color, which is darker and richer than in any of the other thrashers, is one of the best field marks when it can be seen. The crissal somewhat resembles the California thrasher, with a similar, long, curving bill, but it is somewhat smaller and their ranges do not overlap, except in a small section of southeastern California. It is not likely to be confused with LeConte's thrasher, for the latter is much paler in coloration and the habitats of the two do not overlap; the crissal almost never ventures out onto the open desert, and LeConte's is not likely to be seen in the shady thickets where the crissal lives. Mr. Gilman (1909) has this to say about recognizing the three species that are most likely to be seen in the same habitat:

In the field it is somewhat difficult to be sure in distinguishing the three species, Palmer, Bendire and Crissal. At close range, or if the birds are near enough together to compare, it is easy enough; but at a distance a single bird may puzzle.

In general it may be said that Crissal is darkest, has more curve to his bill and has a bobbing, jerky flight quite similar to that of the California thrasher. Palmer is a little larger, apparently at any rate, is lighter in color and has much of the same jerky flight. Bendire is smallest and lightest of the three and has a smooth, even flight. Both Palmer and Bendire have obsolete spots on the breast and light tips to outside tall feathers, but Bendire has the more distinct spots and whiter tall tips.

The crissal thrasher has no spotting on the breast, even when young. "At close range, say on the nest, the eye is indicative. Crissal has a straw-colored iris; Palmer, orange; and Bendire, orange red."

Winter: Crissal thrashers are apparently permanently resident throughout their range, with only altitudinal migrations in spring and fall, up to about 5,000 feet in summer and fall and down to the warmer valleys in winter. Dr. Mearns (1886) says of these movements in Arizona:

The Verde Valley here has an altitude of 3,500 feet, and a much warmer climate than the bordering mesas and foothills, which in winter are often deeply covered with snow. Although they may he occasionally met with in the snow belt, most of them descend into the warmer valleys in severely cold weather. I have seen numbers of them feeding upon the bare sand upon the edge of the Verde River after a snowstorm. Making proper allowance for their being more conspicuous in winter on account of the absence of foliage, the species is undoubtedly far more plentiful in the Verde Valley during the winter season than in summer, when many of those which winter here move upward into the zone of scrub oaks, in which they breed in abundance wherever they can find water within a convenient distance. The exodus takes place about the end of February, after which the species becomes comparatively scarce; and by the middle of March nearly all those remaining are settled and occupied with domestic affairs.

DISTRIBUTION


Range: Southwestern United States and northern Mexico; non-migratory.

The range of the crissal thrasher is north to southeastern California (Palm Springs, Indio, and the Providence Mountains); southern Nevada (Cottonwood Spring in the Charleston Mountains, Vegas Valley, St. Thomas, and Bunkerville); southwestern Utah (St. George); central Arizona (Fort Whipple, Camp Verde, and Pinal Mountains); and southern New Mexico (Carlisle, Cliff, Bosque del Apache, Tularosa, and Carlsbad). East to southern New Mexico (Carlsbad); western Texas (Guadalupe Mountains, Glass Mountains, Marathon, and Boquillas); southern Coahuila (Saltillo and Diamante Pass); and Hidalgo (Portezuelo). South to Hidalgo (Portezuelo); southwestern Texas (Lajitas, Chisos Mountains, and Fort Hancock); northern Chihuahua (Colonia Diaz); and northern Sonora (Guaymas). West to northwestern Sonora (Guaymas, Rancho Costa Rica, and Kino Bay); northeastern Baja California (El Valle de Ia Trinidad, west side of the Laguna Salada, and Gardners Laguna); and central southern California (Alamorio, Martinez, and Palm Springs).

The entire species as outlined has been divided into three subspecies or geographic races. The crissal thrasher (T. d. dorsale) occupies the range in the United States and northern Mexico from Chihuahua to extreme northeastern Baja California; the Trinidad thrasher (T. d. trinitatis) occurs in El Valle de Ia Trinidad between the Sierra Juárez and the Sierra San Pedro Mártir; another race occurs in Mexico.

Egg dates: Arizona: 88 records, February 18 to July 3; 44 records, April 2 to May 21, indicating the height of the season.

California: 56 records, February 10 to June 10; 28 records, March 11 to April 6.

Baja California: 6 records, May 8 to June 10.







TRINIDAD THRASHER


TOXOSTOMA DORSALE TRINITATIS Grinnell


HABITS

Dr. Joseph Grinnell (1927a) described and named this thrasher, based on a series of six specimens collected by Chester C. Lamb in the Trinidad Valley in northwestern Baja California. He says that it is similar to the crissal thrashers of California and Arizona, "but bill longer and distinctly more curved (as seen in lateral profile), and tone of coloration darker, more slaty. This latter qualification applies to both upper and lower surfaces, and particularly to the wings and tail, which are between fuscous and fuscous-black (of Ridgway, 1912), rather than near mummy brown. The bill, feet and claws also average blacker."

This subspecies evidently is isolated in a very restricted range, for he says that it is known only from the vicinity of the type locality in the Trinidad Valley. "This is a rather extensive, east-west valley which separates the Sierra San Pedro Martir immediately on the south, from the Sierra Juarez on the north. The Trinidad Valley is thus part of an intermountain pass, and through it many desert-side plants and animals have gone more or less distance onto the Pacific side, and certain Pacific-side species have extended in the opposite direction."

Its habits are probably similar to those of the northern race.

The measurements of 17 eggs average 27.1 by 19.6 millimeters; the eggs showing the four extremes measure 30.2 by 20.0, 25.2 by 20.2, and 24.9 by 18.7 millimeters.