Bent Life History of the Canyon Towhee
PIPILO FUSCUS MESOLEUCUS Baird
Contributed by JOE T. MARSHALL, JR., and R. ROY JOHNSON
It is curious that the arguments over the relationships of similar kinds of birds (like the two kinds of flickers, meadowlarks, and wood pewees) have never touched the canyon towhee as a subspecies of the brown towhee of California. The two have always been considered conspecific, yet they are isolated .from each other by the Gulf of California and the Colorado Desert, and they differ from each other in voice, habits, and coloration. The shy canyon towhee calls sheddap and has a pleasant jingling song, whereas the bold brown towhee of California calls a sharp chip which also serves, in series, as the rare song. Whereas the brown towhee of California is longtailed and a fairly uniform brown, the canyon towhee of Arizona has a shorter tail, a white belly, a black spot in the middle of the chest, and a reddish-brown crown patch. This line of reasoning unites the two: there is a gradual transition southward from the California brown towhee to a population at the cape of Baja California which resembles t.he canyon towhee in every detail except the chest spot, which is lacking.
Within their large geographic range canyon towhees live in a variety of habitats. All provide open spaces for feeding on bare ground and dense bushes or trees with low growing limbs for hiding. Examples are desert gullies and foothill canyons in Arizona, where the vegetation is giant cactus and paloverde; around sheds, wood-piles, outbuildings, and chicken-coops of the farm; and in the log fences around corn fields and in scrap lumber piles at sawmills in the forested mountains of Mexico.
Territory: Each pair of canyon towhees lives by itself in an area whose size is such that the pairs are generally spaced about 300 yards apart. Unmated males, singing in spring, cover distances three times that in terrain not held by neighbors. But the lone immature bird in winter also remains in a small area. Nests of adjacent pairs have been found no closer together than 175 yards, and successive nests of the same pair have been as far apart as 120 yards. This spacing of canyon towhees implies that each pair or each solitary bird possesses and holds a territory: its place for successful living and nesting.
Most territorial birds advertise their areas by song and fight for them against encroachment by neighbors. Yet canyon towhees have never been seen fighting among themselves. One explanation for this is that the birds are so unobtrusive and shy that they are seldom seen by their neighbors, much less molested. The pair sometimes explores or wanders into the domain of its next-door neighbor, both in winter and when tending its moving offspring, yet the trespass is never challenged. Thus the territory does not seem to be a "defended area," nor is it made conspicuous by advertising song, with the following two exceptions:
The unpaired male in late winter and spring makes himself and his area conspicuous by constant song, but this seems to be to advertise for a mats rather than to proclaim his boundaries to his neighbors. However1 should he sing too close to the neighbor, say within 100 yards, the neighboring male will jump on a tree and sing a few songs in reply. These usually suffice to impel the unmated bird farther away at his next change of song-perch. The second exception is a brief few minutes of actual advertisement at dawn in spring and summer, when all the males, mated and unmated alike, sing just after waking.
Canyon towhee pairs simply have strong inclinations to stay at home and to shun company. Although we might criticize them for being antisocial, still their peaceful means of maintaining the necessary space for security, food, and nesting seems worthy of emulation.
Courtship: As canyon towhees probably mate for life (perhaps only 2 or 3 years at best), there is seldom the opportunity to observe the first meeting of two new mates, though it is conceivable that this might take place in fall when groups of young, having become independent of their parents, scatter and cross paths. Judging from the actions of "old married couples," it is likely that the new pair-bond is ceremoniously ushered in with the usual duet of squeals, uttered while the male is perched in a bush a few inches higher than the female. It can also be imagined from the incessant singing of the unpaired male in spring, that should a female appear in response to his song, the same ritual would follow, and that the singing would come to an abrupt halt.
The male canyon towhee works hard and all year round at making his marriage a success, as if the pair were on a permanent honeymoon. While the female feeds along the ground, he watches from a perch in a bush or low tree over her. He solicitously flies to a new lookout post above her when she moves farther away, and when she flies, he too flies to meet her and to join in the ritual duet of squeals mentioned above. When both birds feed on the ground the male stays within a few inches of his mate, and he raises his head more frequently to look about. At the approach of a person he flies up to a perch and watches, while the female continues to feed in perfect security without even glancing up.
Nesting: The following extreme dates of nesting about Tucson, Ariz., encompass a remarkably long nesting season. Marshall saw a pair feeding young out of the nest on Mar. 31, 1958. A. R. Phillips writes, "My latest nest was in a wash at Wilmot Road, Tucson, 5 feet up in a cholla cactus. It had three eggs on Aug. 28, 1939, small young on September 1, young still there September 6, empty and clean on September 12." The normal number of successful nestings by any one pair at Tucson is not known, but one pair had successfully fledged two broods by May 21 in 1958. Both parents had been color-banded the previous winter. The schedule of their two nestings was as follows: stationary juveniles out of nest on March 31, clutch of four eggs in second nest at least from April 15 to 23, young in this nest on April 30, older juveniles following parents from May 21 at least until June 20. As both parents were tending the fully grown young in May and June, we must conclude they had not yet started a third nest, though another 10 weeks still remained of the potential nesting season. July and August nests could be new attempts after repeated failures, or even first attempts by young of the previous year that matured or paired late.
The solidly constructed nest is generally placed against the main trunk of a small tree or tall bush where it is supported by strong branches and well shaded and hidden by foliage or twigs of the tree. Nests have been found around Tucson on the north, shaded side of cholla cacti, mesquites, elderberries, and hackberries at heights from 3 to 12 feet. In the spring of 1958, young were successfully reared before the trees holding their nests had leafed-out. The female canyon towhee is a close sitter. She flushes only when approached to within 2 or 3 feet, and then silently and inconspicuously.
The bulk of a nest collected and analyzed at Tucson was constructed of small twigs, dry composite stems and heads, crucifer stems and inflorescences, leaves of grasses, leafy ends of stems, and large hollow herbaceous stems. It was lined with elm leaves, small shredded hollow herbaceous stems, fine strips of bark, leafy ends of herbaceous stems, and finally with exceedingly fine stems and spikelets of grasses and with animal hair. C. E. Bendire (1890) gives 5% inches across and 3% inches in height for outside measurements with 3 inches across and 2 inches in depth for inner dimensions. Brewster (1882a) differs slightly with 5 inches across outside, 2 inches in height, 2 inches across inside, and 1% inches in depth.
F. C. Willard (1923) lists some unusual nesting sites. One pair built inside a porch in a robin-like situation. Also listed are the tops of cottonwood trees and honeysuckle vines. H. Brandt (1951) tells of a nest made of plant stems bearing yellow flowers, he thought of the mustard family, "forming a gay golden garland." He also mentions yucca tresses as nesting sites. A. W. Anthony (1892) lists cholla cactus and yucca as favorite nesting sites.
Eggs: C. E. Bendire (1890) gives the following description of the eggs:
The eggs are usually three in number; about one nest in ten contains four; occasionally I have found tbe bird sitting hard on but two, probably a second or third brood. * * *
The ground color of the eggs of the Cafion Towhee is a very pale bluish white, or very light pearl gray, scarcely an egg in a series of one hundred and three specimens can be called pure white. As far as markings are concerned, these eggs can be divided into two types. In one the spots are sharp, well defined, occasionally connected with each other by lines and scrawls, and principally concentrated about the larger end. Their color is a very deep brown, almost a black. This pattern includes the less heavily marked specimens. In the second type, the markings are less clearly defined, more irregular in shape, mere blotches, and much more profuse. The color is less deep, more of a claret brown or vineceous rufous. In addition fine shell markings of lavender and heliotrope purple are scattered more or less profusely over the entire egg in both types. The eggs bear a certain resemblance to those of &u.rnella, especially to heavily marked specimens of the western race, Sturnella magne neglecte. Nearly all the eggs of Pipilo fuscu.s mesoieucus are much more heavily marked than those of the other two races, aside from the racial difference of the ground color, which is also more lustrous. In a series of one hundred and three specimens before me, all but eleven collected by myself, there is considerable difference both in size and shape. The eggs are mostly ovate, some elliptical ovate. The average size of the series before me is .92 x .69 inch. The largest egg measures 1.04 x .71, the smallest .81 x .66 inch, and a runt egg of this species in the collection measures but .70 x .56 inch.
W. G. F. Harris adds: "This subspecies usually lays three or four ovate or short ovate eggs, sometimes only two or as many as five and less frequently six. They are slightly glossy. The ground is very pale greenish or creamy white, with markings of very dark brown and black with under spots of 'light Quaker drab,' or 'light mouse gray.' These markings are in the form of speckles, spots, scrawls, or scribblings rather sparingly scattered over the entire egg, but more numerous toward the large end where frequently a loose wreath may be formed. The eggs with the creamy white ground usually are spotted with dark browns such as 'liver brown,' 'Carob brown,' or 'Hessian brown,' and black with a few spots of gray; those with the greenish white grounds tend to be marked almost entirely with black and gray undermarkings with only an occasional spot of very dark brown such as 'chestnut brown.' Many eggs are marked only with spots or small blotches of the grays with a few spots or scrawls of black. The measurements of 50 eggs average 23.4 by 17.5 millimeters; the eggs showing the four extremes measure 26.9 by 16.8, 25.4 by 18.8, 20.6 by 16.8, and 20.8 by 15.2 millimeters."
Incubation: Only the female incubates. Every few hours she leaves the nest to feed under the watchful eye of the male, solicitous as usual. A sure sign of incubation is the singing of the male past the normal short period at dawn. He sings loudly and constantly from a conspicuous perch in a tree almost all the time she is incubating; he stops singing and joins her the moment she leaves the nest to feed. No accurate data are available on the length of the incubation period in this race.
Young: Upon leaving the nest, the young climb up into the bushes or low trees and remain stationary for long periods while uttering a high, thin sip food call. The parents use the same note, but much louder and more piercing, as an alarm note; when uttered it silences the foodcalls of the young. Only when much older do the young begin to move after the parents to be fed. Then their note has filled out to the ordinary locative see.
Groups of canyon towhees seen in some autumns may be families of young still staying near their parents. Thus in mid-November Marshall saw two birds with a color-banded adult female in an area where canyon towhees are rather uncommon. They may have been her young, as they were all feeding together at a feeding station about 10 yards from a bush in which she had nested the previous spring. A. R. Phillips writes that his latest record of a "flock" (family?) of three or four birds was on Feb. 19, 1939.
Plumages: The natal down is brown. At the time of leaving the nest the fully-feathered juvenile has a bobbed tail and is in a lacy brown coat with spotting on the chest, somewhat like that of a thrush. During October the post-juvenal molt is completed. This replaces the thin lacy body and head feathers with firmer, more solidly colored feathers like those of the adult. However, the nestling wing and all or most of the tail feathers are retained. A year later, in fall, a complete molt renews the adult body plumage and at last endows the now mature bird with adult wing and tail feathers. These have perfect margins and are broader, blacker, and more square-ended than are the corresponding juvenal feathers of fall immature birds. Therefore, the bird bander can easily tell the sex and age of his captured birds by these plumage criteria (for age) and measurements of the wing and tail (for sex) as set forth and explained in detail in John Davis's (1951) monograph of the brown towhees.
Food: AII the feeding is done on the ground, where seeds in winter and insects in summer are picked up in the bill by repeated dabs while the body is held horizontal. Birds often scratch the ground by jumping and moving both feet simultaneously to scuff dirt and leaves out toward the rear. But scratching is not as incessant in the canyon towhee as in the rufous-sided and green-tailed towhees, nor does it seem as frequent as in the Abert's towhee. In winter-taken stomachs, m addition to a great variety of seeds, there are little colorful crystals the birds pick up daily to help grind the seeds in the stomach.
During the nesting season parents gather insects by the beakful for their young. Both parents have been seen to feed young out of the nest, each parent apparently providing for a certain offspring. In one family, the male seemed not to be gathering food. Instead, he sang while the female was out of sight, then carefully supervised her approach to feed the stationary young out of the nest by duplicating her path higher up.
Behavior: The canyon towhee is normally one of the shyest birds of southern Arizona. A few fortunate persons who live in foothill homes where natural vegetation of saguaro and palo verde is preserved have birds about their yards, visiting their drinking or feeding stations, which become fairly tame. So are those that live afout Indian homes and dooryards in rural Mexico. But in wild country the birds, though known to be present, can avoid being seen from dawn until dusk. In fall and early winter, when they call least often they may utter the call-note only five or six times at dawn, and perhaps a few more times in succession at dusk. During the rest of the day they may have only three or four other periods of brief calling, or of squealing in the case of a pair. In winter the towhee calls as much while going to roost as it does during the rest of the day. In the gloom of dusk it will ascend to a post to call for a few minutes before flying to a dense bush to roost 4 to 8 feet off the ground.
The canyon towhee especially likes to feed under things: under bushes, log fences, old buildings, and chicken-houses. Lew Blatchley reports that at Silver City, N. Mex., a favorite resort for the canyon towhees is under his parked car. At Tucson they have been seen feeding under trailers, under wagons on the farm, under dense patches of tumbleweeds, under mesquites, and within tall grasses.
When it feeds in the open, the canyon towhee always stays within a few feet of dense bushes, to which it retreats even when other kinds of birds of lesser size fly by or alight, as at a feeder. Also the towhee keeps on the move, no matter how abundant the food at a particular spot. It may scratch in one place for five minutes or more, but usually it samples the feeder's offering, runs back into the bushes, and moves on.
C. F. Batchelder (1885) encountered the canyon towhee at Las Vegas Hot Springs, N. Mex., in December 1882. He had this to say of the behavior of this race:
In the willows along the river bank the Cafton Towhees (Pipilo fuacus mesoleucus) were sometimes to be seen, though they frequented other places as well.
Among their resorts were the small cliffs scattered along the river, whore they poked about among the masses of fallen rocks at their bases, and in the clefts and gullies by which they were int&~rsected. They were apt to be found, ten, about the Mexican villages, where they might be seen perched on the high adobe walls surrounding a courtyard, or exploring the ruins of some deserted house that offered a safe retreat in case of alarm. Perhaps, however, the places where they ware most numerous were some small irrigated fields on the outskirts of one of these little villages. Where these fields bordered the river or an irrigating ditch, they were fringed with bushes, chiefly willows, that were a favorite haunt of the Towhees. Here one would sometimes be seen running along and then stopping, somewhat like a Robin on an earthworm hunt. Their run really consists, however, of a series of rapid hops. There is much that is Thrush-like about their air and motions, and if seen from behind one might almost be mistaken for a Robin, its form and attitudes are so similar, though it does not stand as upright as a Robin very often does. As a rule they kept on the ground hut now and then they would get up in a bush or even in a low tree, but as soon as a Towhee saw he was attracting attention he immediately shifted his position or retired silently with a swift low flight to some safer place.
Though they commonly go in small flocks I am inclined to think that some at least remain paired throughout the year. They are not infrequently found in couples; in one such case dissection proved them to he male and female; in another when I had shot one bird the survivor showed evident signs of distress.
F. M. Bailey (1923) says of the canyon towhee: "It was one of the commonest birds of the mesquite and catsclaw as well as of the canyons in the region of McClcary's (Nicholson's) during the winter and spring of 1920: 1921. Several were caught. in traps set for live mammals, evidently attracted by the popular rolled oats." She also mentions finding it in January 1923 in groups of two, thee, or four on the ground along roads.
Voice: The usual song of the canyon towhee is a series of six or seven double syllables, all alike and evenly spaced, as chili-chili-chilichili-chili-chili. The song may begin or end with a different note, or it may begin with a faint rendition of the usual call note. Some series are of single notes, others are in fine trills like those of juncos. At its worst the song is a dull series of chilps, but at its best it is a gay, sustained jingle to be compared with that of a titmouse. A male whose dawn singing has been dull and perfunctory during late winter and early spring will become transformed into a polished singer when his mate disappears to incubate. At that time it is evident, as it has been in unpaired males, that the charm is lent by the variety of the songs resort.ed to, each variation prevailing for a series of several songs. The more brilliant the songs, the more frequently are their patterns changed.
The ordinary call note, used also as an alarm note, is a two-syllable tscheddap, of which the second syllable may be suppressed to tschedd'p. This call is explosively uttered and is "rusty," that is, rather hoarse.
The duet squeal is exactly the same as that of the California brown towhee and is uttered under the same circumstances, in ceremonial reaffirming of the pair relationship. It can be represented as squealehurrrr or squeal: sq~ieal-squeal-squeal, which can readily be told in the field from the laughing squeal-cha-cha-cha or squeal: hah-luili-hah of the Abert's towhee.
Birds keep in touch by an occasional unquavering locative note, see. It is similar to the food call of the young and to the louder warning call of the parent mentioned earlier. Finally there is a light tie of alarm, uttered when an intruder comes near the nest.
Bailey (1923) reports that the commonest call resembles that of the California towhee, seree-kee-gee, kee-gee-kee. She likens the one quick call note to that of the Gila woodpecker.
Field marks: The traveler of country roads through river-bottom farmlands in southern Arizona will flush before his car numerous nondescript brown birds of medium size from the mesquites and hackberries of the fence rows. These are Bendire thrashers, curvebilled thrashers, crissal thrashers, female cardinals and pyrrhuloxias, Abert's towhees, and canyon towhees. Of all these, the canyon towhee has the broadest and shortest tail for its size. It does not constantly jerk or bob the tail, as do the pyrrhuloxias. The canyon towhee is the only member of this group with a lone central dark breast spot. This attribute eliminates everything but the strikingly handsome, white-flashing lark sparrow. Of course when the bird is on the ground its spot cannot be relied upon, especially if it is under shady bushes. Then it can easily be mistaken for an Abert's towhee. However the light face and fairly dark bill of the canyon towhee is in great contrast to the whitish bill and black area around its base, by which the Abert's towhee presents a different appearance almost as far as it can be seen.
Enemies: Apparently little is known of the enemies of the canyon towhee. Herbert Friedmann (1934) states that Griffing Bancroft has two sets of eggs from Santa Fe County, N. Mex., which had been parasitized by brown-headed cowbirds (Molothrus ater).
External parasites of the families Ricinidae and Ilippoboscidae have been found on specimens banded near Tucson.
Range: T he canyon towhee is resident from western Arizona (Black Mountains, Kofa Mountains, Papago Well) east through New Mexico (except Union County in northeast), south to northern Sonora (lat. 300 N.), northern Chihuahua (lat. 310 N.), and extreme western Texas (El Paso, Guadalupe Mountains).
Casual record: Casual north to Grand Canyon, Arizona.
Egg dates: Arizona: 73 records, March 3 to September 8; 38 records, May 2 to June 12.
New Mexico: 20 records, March 22 to July 8; 10 records, May 21 to June 13.
PIPILO FUSCUS RELICTUS van Rossem
Contributed by JOHN DAVIS
This race, described by A. J. van Rossem (1946b), has a very limited distribution in Yuma and Maricopa counties, Ariz., where it is restricted to the Harquahala Mountains and Eagle Eye Peak. P. f. relictus allegedly differs from P. J. mesoleucus in the relatively darker coloration of its dorsum, sides, flanks, and throat. However, the brown towbees of the Harquahala Mountains vary considerably in color, and many individuals are indistinguishable from mesoleucus.
The Harquahala brown towhee is resident in a vegetation composed in part of scrub oak, manzanita, mountain mahogany, Ceanothus, and laurel, which differs markedly from the surrounding desert vegetation at lower elevations. Nothing is known of its life history.
Range: The Harquahala brown towhee is resident in the Harquahala Mountains in southwestern Arizona, above 2,500 feet.
PIPILO FUSCUS MESATUS Oberholser
Contributed by JOHN DAVIS
This subspecies, described by H. C. Oberholser (1937), is differentiated from P. f. mesoleueus by its paler pileum, browner coloration of the dorsum, sides, and flanks, longer wing, and higher wing-tail ratio. A locally common resident of the pifion: juniper association of southeastern Colorado, northeastern New Mexico, and northwestern Oldahoma, the Colorado brown towbees are limited in their occurrence to the west by the eastern ranges of the Rocky Mountains, and to the north by the constriction of the pi~on: juniper association north of the Arkansas River.
Cooke (1897) states that mesatu~s breeds in the latter part of April, nesting in juniper and sometimes in cacti. Nice (1922) found three nests near Kenton, Okia., on June 1 and 2. Two nests contained three eggs each, and the third held three young. One nest was in a pifton, one in a juniper, and the third in a tree cactus. Late nesting of some individuals is indicated by the collecting of a female almost entirely in juvenal plumage on Oct. 4, 1932 (Sutton, 1934).
Range: The Colorado brown towhee is resident in southeastern Colorado (mainly south of the Arkansas River, sparingly north to Boulder), northeastern New Mexico (Union County), and extreme northwestern Oklahoma (Kenton).
PIPILO FUSCUS TEXANUS van Rossem
Contributed by JOHN DAVIS
Described by A. J. van Rossem (1934c), the race texanws resembles mesoleucus in color, but can be distinguished from that race by its darker pileum, shorter tail, and higher wing-tail ratio.
The Texas brown towhee occupies two main centers of distribution: the broken, mountainous country west of the Pecos River and the Edwards Plateau. Recently, its range has been extended south to the Sierra del Carmen, in northern Coahuila, Mexico (Miller, 1955a). West of the Pecos River, tezanats occurs in the pifion: juniper association. On the Edwards Plateau, brown towhees have been found in oak: savanna pastures, juniper brakes, and dense thickets of "shinnery" oak. Lloyd (1887) found a nest of this towhee containing three incubated eggs in the fork of a small live oak tree in Tom Green County. He states that nests found farther west contained five eggs each, and he considered three eggs an exceptionally small clutch. Van Tyne and Sutton (1937) found three nests in Brewster County on May 20, 30, and 31. One nest contained two eggs and two contained three eggs each; all eggs were fresh. Parents were seen feeding short-tailed but fully fledged young on May 2 and 4.
Range: The Texas brown towhee is resident in northern Coahuila (Sierra del Carmen) and in the plateau area of western and central Texas from Reeves, Tom Green, and Kerr counties to Val Verde County.