Wrentit

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

The coast wren-tit is the northern race of this California species. it occupies the humid Transition Zone on the Pacific coast of Oregon, from the Columbia River southward to the vicinity of the northern boundary of California. Like many other races of that humid coast strip, it is the darkest race of the species. Ridgway (1904) calls it the dusky wren-tit and describes it as similar to the ruddy wren-tit, its nearest neighbor on the south, “but still darker, the back, etc., deep sepia brown, the pileum and hindueck nearly clove brown, the general color of under parts deep vinaceous-cinnamon or fawn color, with streaks on throat and chest broader (those on throat nearly black).” Evidently the colors of the different races of this species become progressively darker and richer as the range extends northward.

Bernard J. Bretherton (Woodcock, 1902) says: “This species is only met with on a strip of land lying directly along the ocean. Its range is inseparable from the Manzanita bush, and, as far as I know, Yaquina Bay is the limit of its northern range, and it is not found anywh?re in our state east of the Coast Range.”

Dr. Mary M. Erickson (1938) has contributed such a full and interesting life history of the type race, Citamaca fa.sciata faaciata, that there is practically nothing to be added on the habits of this subspecies and very little on the habits of the other races.

There are four nests of this wren-tit, with sets of four or three eggs each, in the Thayer collection in Cambridge. One was placed in a maple bush, one in a salmonberry bush, one in a huckleberry, and one in a myrt]e bush. They are all neat and compactly woven baskets, deeply hollowed and with the rims curved inward at the top. They are made of a variety of plant fibers, weed stalks, and weed blossoms, bound together with strips of grapevine bark, fine grasses, cattle hair, and spider webs; the lining consists of still finer grass and much horsehair or cowbair. One nest has considerable green moss worked into the rim. Externally they measure about 3 inches in height and about the same in diameter; the inner cavity is about 2 inches in diameter at the top and about 1½ inches in depth.

The eggs are indistinguishable from those of the other races of the species. They vary in shape from ovate to short-ovate and have only a slight gloss. The color varies from “pale glaucous blue” to bluish white, and they are immaculate. The measurements of 24 eggs average 18.6 by 14.1 millimeters; the eggs showing the four extremes measure 21.4 by 14.0, 17.8 by 14.7, 17.4 by 14.3, and 17.8 by 13.5 millimeters.

RUDDY WREN-TIT
CHAMAEA FASCIATA RUFULA Ridgway
HABITS

Farther south along the coast of California, from Del Norte County south to Santa Cruz County, in the humid coast strip, is the range of the ruddy wren-tit. This race is not so dark as the coast wren-tit, but it is darker and more richly colored than the type race, Gambel’s wren-tit, of the San Francisco Bay region. Ridgway (1904) characterizes it as “similar to C. f. fczsciata, but more richly colored, the general color of under parts deep pinkish cinnamon or dull vinaceous cinnamon, the upper parts darker and browner (back, rump, and upper tail-coverts bistre or sepia)?’ Apparently what has been written about the habits of the neighboring type race would apply equally well, in most respects at least, to the subspecies. I can find nothing in the literature to indicate anything peculiar in its habits. Its rich coloring is probably due to its humid coast habitat.

There are two sets of eggs with nests of this wren-tit in the Thayer collection in Cambridge. One nest, containing three eggs, was placed against the trunk of a fir tree among some azaleas, at Eureka, Calif. The other nest, taken at Sonoma on May 17, 1895, contained five eggs; this nest is similar to nests of the coast wren-tit but is somewhat less bulky and made of finer materials, with many spider nests on the exterior, and lined with very fine grass and hair; it measures 2½ inches in height and 3 inches in diameter, externally; the inner cavity is2 inches in diameter and 1% inches in depth.

The eggs are indistinguishable from those of the other wren-tits. The measurements of 35 eggs average 18.3 by 14.3 millimeters; the eggs showing the four extremes measure 21.0 by 14.8, 19.9 by 15.0, 16.6 by 14.3, and 18.4 by 13.8 millimeters.

GAMBEL’S WREN-TIT
CHAMAEA FASCIATA FASCIATA (Gambel)
CONTRIBUTED BY MARY M. ERICKSON
( Derived largely from Erickson, “Territory, Annual Cycle, and Numbers in a Population of Wren-tits,” 1938.)

HABITS

The wren-tit is a bird that many do not have an opportunity to know, since it represents a monotypic family and its range is restricted to a narrow belt along the Pacific coast from south of the Columbia River down into Baja California. It is principally a bird of the wind-swept brushland of the immediate coast at the northern end of its range, but in California it is found everywhere west of the Sierras in the extensive chaparral belt or in the brushy margins of the forests and streams. Even in the area in which it occurs it is better known by its voice than by its appearance. Casual visitors to the chaparral ask what bird makes the loud-ringing call that may come from the distant ridge or with surprising suddenness from within the nearby bushes. But even~ if one knows it is nearby it is not easy to see this dweller of the brushland, for it rarely leaves the endless expanse of twigs within the leafy crown to come into the open at the top or to the ground below. If one has the time and patience to waitnearby, its own curiosity will often bring it within view. With practice one can glimpse them, but it is never easy to see them clearly or follow them for any distance.

The subspecies under consideration, which lives along the coast from San Francisco Bay south to southern Monterey County, I watched intensively for four years. Most of the work was done in a small canyon containing 16.7 acres of brush near Berkeley, Calif~ In this canyon nearly all the wren-tits were banded and marked so that they could be recognized as individuals.

Spring: The wren-tit is classified as a permanent resident, and this residency is of the most restricted sort. Individuals probably rarely go more than a few miles from the place of their birth. Adults that have once nested spend most of the remainder of their lives on the half to two and a half acres of brushland used during the first nesting. In spring, then, the wrentit population is essentially static. Pairs are established on breeding territories, many of them with the same mate on essentially the same territory they have held a year or more. Individuals that have died have been replaced by a male accepting a new mate from among the young-of-the-year or a widowed female joining a bereaved male or a young male establishing himself. All suitable ground is held by one pair or another. A few individuals, either unable to secure a territory or mate, or for some reason not ready to do so at the normal time, wander through the territories of established individuals and are driven from one to another by them. However, vacancies that may occur are quickly filled from the ranks of these wanderers.

The activities of the pair at this time, as they are all the year except during the breeding season, are concerned with finding food for themselves and defending their territory. The pair are constantly together as they work through their segment of the limitless chaparral hunting for food. They keep in touch with each other by frequent calls. The male often pauses to sing, and echoing calls are given by other males.

If a jay perches nearby, they scold it. Occasionally they pause to rest or preen. If their movements bring them to the margin of their home area or territory, they usually turn back and continue the endless search for food. If they continue until they reach the extreme limit of their territory or go into the margin of the adjoining one, they are invariably met by the owners of this area and a boundary dispute occurs. The fighting that takes place is never prolonged or violent, and the infringing pair soon retreat to their own area and both pairs continue to forage. Rarely, an individual seeking to establish itself may invade the territory and is persistently harrassed by the owner as long as it remains, or possibly, if the territory is unusually large, the owner will relinquish part of it to the newcomer.

Courtship: Courtship activities of a pair so constantly hidden are not easily observed. Pairs seemingly are originally formed by a female joining a male that has, or is establishing himself on, a territory. Two birds of the year, which I believe are a male and a female, are often seen together during fall and winter, but these seem to be transitory attachments, and the female will leave such a male to join an established one.

I once observed what appeared to be the establishment of a male on a territory and his acquisition of a mate. In a patch of brush that had not been occupied on the previous days, a young banded male was observed in the morning between 7:30 and 9 o’clock. During this time he went from the upper end to the lower and back to the upper, and except for a few brief intervals sang on an average of 5 times a minute: approximately 450 utterances. When he was at the top the second time, his calls were low and of poor carrying quality, but here a second wrentit was heard and glimpsed for the first time. The two moved down the the slope again. I heard no sounds except a single song and a krrr answer, but low notes would not have reached me. About 9:30 the pair were lost in the lower part of the territory. At 11 :30 I looked for them again and found them behaving as any established pair would behave.

What actions take place as the pair first meet were never seen in the field. When a female was put into a cage containing two males and a female, the subsequent rapid movements of the four birds were exceedingly difficult to follow. The actions of the original female were mainly hostile. Lightning advances and retreats occurred between the two males and the new female, accompanied by a variety of soft musical and harsh notes as well as those common during disputes. The frequency of these chases decreased markedly by the end of the day, and soon the new female acted as the typical mate of one of the males.

Most of the time there is little activity to indicate that two birds are mates except their constant companionship. They forage together, they frequently preen each other, they rest on the same perch during the day, and they roost together at night. Their interest in each other moves toward a peak, as shown by sexual flight and special versions of the song as they build the nest, and it reaches its climax in coition on the days the nest is lined. In sexual flight the female continually hops or flies away from the male as he approaches, so that a rapid chase takes place. Posturing was never observed, but it may occur, since it would be difficult to observe it.

Once mated, the pair remain together as long as both are alive. Of the pairs I knew, five existed at least three years and a sixth for 2½ years. Six pairs were together for 2 years and may have existed prior to or after my knowledge of them. Only five pairs were known to have lasted only 1 year. When a pair was broken up, one or both members of it disappeared completely and presumably must have been killed, though this was only definitely known to be true in 1 of 17 cases.

Nesting: The nest is placed in one of the bushes that make up the chaparral home of the species. It is usually not in a continuous dense mass of brush, but at its margin where a rock outcrop, less in height than the brush, or a trail or clearing makes a break; or if the chaparral is sparse the nest may be in any small bushy plant. I have found nests in coyctebush (Bcwcluzris pilularis), artemisia, hazelnut, stick monkeyfiower, and poison oak. Mailliard (1902) and A. II. Miller (MS.) have found them in live oaks, and Ray (1909) in an alder. In chaparral where other plants dominate, other shrubs are used.

From the nature of the habitat, the height of the nest above ground usually cannot be great and averages 18 to 24 inches. The lowest that I found was 12 inches, the highest 42 inches. The nests in trees mentioned above were 12 and 15 feet up.

Support, both under and at the sides of the nest, is usually found in a group of horizontal or vertical twigs built into or lashed to the nest. Occasionally a crotch of larger limbs is used. The nest is placed so that leafy twigs screen it from view on all sides.

The nest, a compact cup, is built by both members of the pair. It is begun by stretching a cobweb network between the twigs that are to form the support. Then coarse bark fibers are introduced, sparingly at first, until a saucerlike platform from ½ inch to 11/2 inches thick and about 4 inches in diameter is formed. Fine bark strips are then placed on the outer rim until a deep cup is formed. Throughout the construction of the platform and cup, masses of cobweb are stretched over and interwoven with the bark fiber to bind it together and hold it in place. Cobweb is also stretched over the rim until it becomes smooth and firm. Finally a lining of fine round fibers is inserted in the cup, and tiny bits of lichen may be, though are not always, fastened to the outside. The type of bark used depends largely on the type of brush nearby. I have seen them strip bark from the dead or weathered branches of old-man sage, lupine, snowberry, thimbleberry, ninebark, baccharis or coyotebush, cow parsnip, and elderberry. The lining was often taken from the outer coat of the bulb of the soap plant, but fine grasses or hair are also used. Abandoned nests are a common source of material for later nests. The difficulty of finding nests makes the case uncertain, but I believe only one nest is worked on at a time, though a nest may be left incomplete and another begun.

The nest, though it may be the center of the birds activity for upward of a month, is not necessarily near the center of the territory. Of 47 nests that I observed, 60 percent were near the margin rather than the center. Successive nests of the same year or succeeding years may be near together or widely separated. The male often sings within 25 feet or less of the nest as he goes to it or leaves, but with equal frequency from other parts of the territory.

Eggs: The number of eggs in a set is usually four, but sets of three are not infrequent and sets of five occur occasionally. There is some evidence that the smaller sets are laid by the younger females or early in the season and the larger sets by older females or late in the season. The eggs are usually laid early in the morning on successive days. They are oval and of a uniform pale greenish blue. There are no markings of any kind and the surface is dull. A single brood of young is reared each year, but if the eggs or nestlings are destroyed, the birds will lay as many as four or five sets during the nesting season, which at Berkeley lasts from March to July.

[AUTHOR’S NOTE: The measurements of 40 eggs average 18.1 by 14.5 millimeters; the eggs showing the four extremes measure 19.6 by 16.0, 16.3 by 14.2, and 17.8 by 12.7 millimeters.]

Incubation: The incubation period was 16 days for three sets of eggs that I observed and was probably the same in two other cases. Newberry (1916), however, obser’i~d a nest in which the eggs hatched in 15 days. The adults spend at least some time on the nest after the second egg is laid, but in all cases that I observed, continuous incubation began on the day the next-to-the-last egg is laid; hence usually on the day the third is laid. In the nest watched by Newberry a lapse of 3 days occurred between laying and the beginning of incubation.

During the days of incubation the activities of the pair follow a set pattern. The female incubates at night. About 20 minutes after sunrise (the wren-tit is a relatively late riser) the male sings from his roosting perch. The female responds with her call, and both often repeat them. In 10 or 15 minutes the male comes to the nest bush, and when he is within a few inches the female leaves. Her first action is to stretch thoroughly, then in a fei moments she is off in search of food. In 15 or 20 minutes she returns, and when she is close to the nest her m&te leaves. He sings almost at once and frequently while he is foraging and patrolling his territory and as he approaches the nest again. Similar exchanges continue throughout the day though the shifts gradually lengthen to 45 or 60 minutes during midday and again shorten toward sunset. Finally when the female returns to the nest within 30 minutes or less of sunset no more changes.occur. The male sings often as dusk approaches, and his last songs come from near or on the roosting perch.

Young: The eggs of a set hatch within a period of 24 hours. In two nests that I observed, two eggs hatched early one morning, a third later in the day, and a fourth the following morning. During the first 35 days the young are constantly brooded by one or the other of the adults except for the brief moment when one leaves and the other feeds before settling on the nests. Older young are left uncovered for short intervals during the warm parts of the day and may not be brooded at all the last few days before fledging.

Food is brought on each return of the adults at intervals at 15 to 30 minutes when the adults are brooding and of 5 minutes or less when the young are older. The food, which is carried in the bill and is often a conspicuous mass of green larvae, is placed in the mouths of one or more young while the parent perches on the rim of the nest. At first there is usually some for each of the three or four young, later only one or two receive food at each visit. The first to raise its head if only by a fraction of a second, is served first. One receiving no food will continue to hold its head up, and often the adult rapidly and repeatedly thrusts its bill into the upturned throat. There is probably no regurgitation of food, for the bill and throat of the adult seem quite empty. The slight jar caused by the adult landing on the nest or nearby twigs is the signal to the young that a meal is at hand. rrhe adults seem to have no specific calls to their young. The fecal sacs are eaten by the adult, if it remains on the nest, or are carried away. if it does not brood.

The young are naked at hatching. By the third day many of the feathers show as slight irregularities on the surface. By the fifth day the feathers show as slight ridges, with the tips protruding above the surface of the skin, and the resting posture is upright rather than on the side. By the tenth day the young when huddled in the nest seem completely covered but the feathers do not actually cover the apteria until the twelfth or thirteenth day. At this age the young stand up in the nest, stretch, preen, vibrate their wings, and give a faint food call.

On the fifteenth or sixteenth day after hatching, the young leave the nest. On two occasions of which I have record, they left before I 30 on the fifteenth day. One family was evidently frightened from the nest when only 13 or 14 days old, and two of the three young survived. The brood that Newberry watched all left the nest explosively at 1: 30 on the sixteenth day. Twice that I know of, one of the young remained in the nest several hours or a day longer than the others. At the time the young leave the nest, the body is well covered, but the wing feathers are not fully grown and the tail is scarcely an inch long. The iris is white as in the adult.

The first day out of the nest the young are easily located by their frequent calls. They remain perched most of the time. If forced to move they progress by a series of short hops accompanied by probably useless fluttering of the wings, but they are not sure-footed and if hurried often fail to gain the intended perch and scramble desperately to gain a footing and recover their balance. I was able to catch and band two such families. By the following day the young respond to the alarm note of their parents with frozen silence, and it is next to impossible to locate them. They also move with such facility that they cannot be taken. By the fifth day they move with as much skill and ease as the adults. By the time the young are 30 to 35 days old they are probably securing some food for themselves, but still beg from and are fed by their parents. A week later they scold as do the adults. By the time they are 9 or 10 weeks old they are no longer dependent on the adults and wander or possibly are driven, from the adults’ territory.

Plumages: The young at hatching are without down and the only vestige of a down plumage that ever develops is the 2- to 3: millimeter neossoptiles on the tips of the rectrices.

[AUTHOR’S NOTE: Ridgway (1904) says that the young are “similar to adults but texture of plumage looser, color of pileum and hindneck less grayish (concolor with that of back) and that of under parts duller and grayer.” A small young bird in my collection, of the subspecies hen.shawi, in juvenal plumage, fits the above description, except that the under parts are more buffy than in the adults, “pinkish buff.”

The postnuptial molt of adults, and apparently the postjuvenal molt of young birds, occur mainly in August, though some young birds may molt earlier in the season. I have seen adults in worn plumage up to August 10, others that were still molting on September 10, and still others that had nearly or quite completed the molt on September 3.]

Food: The wren-tit’s diet consists of insects, which are taken all the year but in great abundance during spring and summer, and small fruits, which are taken when available, principally during fall and winter. F. E. L. Beal’s (1907) study of 165 stomachs shows that, of the 48 percent of vegetable food taken, 36 percent consisted of elderberries, snowberries, coffeeberries, twinberries, blackberries, and the fruit of poison oak. The poison-oak berries, which remain in an edible condition on the bushes for a long time, made up a fourth of the diet from August to February. I have seen all of these fruits eaten and in addition thimbleberries, huckleberries, and toyonberries. The insect food that Beal found to make up 52 percent of the food consisted of 23 percent ants and small wasps, 10 percent beetles, 8 percent caterpillars, 7 percent bugs, principally scales, 2 percent spiders, a few flies, and in one case each the remains of a grasshopper and a woodcricket. I successfuly kept wren-tits in captivity on a diet consisting of mixtures for soft-billed birds, banana, cottage cheese, lettuce, bread crumbs, and occasional live insects and wild berries. The young are fed principally on caterpillars, spiders and their cocoons and eggs, leafhoppers and other bugs, and small beetles. I have also seen adults come to a feeding table and get bread crumbs to feed their nestlings and fledglings.

The wren-tit finds its food principally on the bark surfaces, and to a less extent on the leaves and fruiting stems. Rarely they go to the ground. Not infrequently an individual flies up and hangs inverted while hunting among the leaves of live oaks for larvae, as a bushtit or titmouse might do. A few times individuals hovered at sticky monkey flowers. Once one caught a small butterfly which flew near, snipped off its wings, and swallowed the body.

Small objects, such as most of the insects and poison-oak berries, are swallowed whole; large ones are broken up. After obtaining a large morsel, the wren-tit resorts to a twig, places the object under one foot, and pulls off small pieces with its bill. Snowberries and thimbleberries are regularly handled in this way, elderberries sometimes. The berry is pecked until the skin is broken, and then pieces are pulled off and swallowed. Seeds met with are discarded, though the large flesh-coated seed of poison oak is swallowed and later disgorged. Large bread crumbs were held with the foot, or small pieces were broken off with a quick shake of the head.

Wren-tits drink water when it is available either from pools or the drops of moisture that collect on the leaves, but in much of their range they appear to do without water for periods of several weeks.

Behavior: A wren-tit’s habitat is such that most of its movements are a series of hops or flights of a few feet from one twig to the next. Individuals do not cross open spaces of even 30 or 40 feet readily or frequently. The longest flight I observed was about 150 feet over open grassland, but such flights are unusual.

Care of the plumage, which involves the usual preening and bathing, has two features of special interest. Preening is usually done by the individual’s working over the feathers with its bill, or where the bill cannot reach, with its foot. Not infrequently, however, the members of a pair or family preen one another. The activity is usually limited to the region of the head but sometimes includes the feathers of the back, sides, breast, and crissum. The method is always the same: the bill is thrust into the feathers and a single one is manipulated between the mandibles from the calamus to the tip of the vane. Bathing in puddles when they occur near bushes includes the usual bobbing and splashing, but the plumage is moistened by a series of momentary dips rather than one long one. Rain- or fog-moistened brush is perhaps a commoner source of water for bathing. Birds move about in the leafy crowns, brushing and bumping against the wet leaves until their plumage is well dampened, and then the customary shaking and preening take place. Once a bird was observed to dust-bathe.

I observed the roosting habits in both cage and wild birds and found that the pair, and presumably a family, roost together. A pair sit side by side, facing in the same direction and so near together that they appear as a single ball of feathers from which tails, wings, and feet protrude: an appearance that is not accidental but is produced by fluffing, spreading, and interlacing the body feathers to such a degree that when the heads are turned to the outside and buried under the scapulars a single ball remains without so much as a line of separation. This arrangement of the feathers is an active process involving both movements of the feathers by the muscles that control them and manipulation of them with the bill. Usually the birds sit so low that the body feathers touch the perch and partly conceal the toes, but sometimes the bodies are well above the perch and then one can see that the inner leg of each bird is drawn into the feather mass and the weight supported on the outside leg. The angle of the leg to the body suggests that the two birds are braced against each other. In the wild the roost is a horizontal branch within the crown of a bush. The same roost is used frequently but not necessarily on successive nights.

The fighting between adjoining pairs that takes place during boundary disputes rarely deserves the name. The head, feathers of the contestants are raised, the long tail cocked sharply up, the body crouched and tense. Each bird eyes its opponent and shifts its position or perch as if sparring for an opening. One or more may utter a staccato tsr tsr or a continuous pit. This action may go on for only a moment or for 15 minutes or longer. If it is prolonged one bird may fly at the other, but the latter makes a quick shift and is a foot or two away when the attacker reaches the empty perch. This continues as the opponents move rapidly through a bush, or along the boundary or back and forth across it. Sometimes the pursuer becomes the pursued. Rarely, the combatants fly at each other and momentarily flutter through the brush or on the ground, bills clicking and wings striking. Eventually one pair, usually the invaders, works back toward the center of its territory, and the other soon does likewise. The defending male usually sings, the invader sometimes does.

Wren-tits are persistent in scolding the California jays, which enter their territory during the breeding season. When a jay is discovered the pair circle or follow it, oonstantly hopping about and uttering a krrring sound until the jay moves on out of their territory. The jays seem quite indifferent, but I found this habit useful in two ways. One was in marking the territory of a pair by where they began and ceased to scold jays. The other was to attract marked birds I wished to identify to a given point by putting up a mounted jay. This ruse worked only for a short time, but it did enable me to learn the identity of several individuals.

Various actions of the wren-tit disclose the approximate location of the nest, though in my experience the nest is not easily found. An intruder near the nest is scolded persistently and vigorously with a krrring note, which becomes intenser as one nears the nest and decreases as one moves away from it. During the incubation period patient watching and listening should indicate the point from which the male sings as he goes to the nest and as he leaves. In either case, a search of the likely bushes in the region so indicated may reveal the nest. Finding the nest by watching adults carrying food is comparatively easy in this species. I never found that a random hunt through the bushes paid dividends.

The reaction of a wren-tit on a nest to an intruder varied in my experience. If the approach is quiet, the wren-tit usually remains on the nest until the hand is brought within a few inches. Then it silently slips off into the surrounding brush. Here it may remain quiet or it may scold. Sometimes the song or pit-pit call is given. Twice I was successful in painting a spot on the tail of an incubating bird. Three times birds with young exploded from the nest and fluttered and tumbled through the brush rapidly vibrating their wings, but these cases were the exception.

A wren-tit rarely, if ever, deserts eggs or young. Several nests I found in the early stages of construction were subsequently completed and used. Others were not, though there was no direct evidence that my discovery caused the desertion. One pair continued to incubate although work on a nearby trail pulled the nest into an exposed position at the top of the brush.

Voice: The wren-tit is best known by its song, a series of loudringing whistlelike notes all on the same pitch and given at decreasing intervals until they run together into a trill. Grinnell (1913) recorded it as pit: pit: pit: pit: pit-tr-r-r-r-r. Slight variations occur. A common one is an increase or decrease in the number of “pits”. Another, peculiar to a few individuals, is a short tr note at the end of the trill. Other variations of quality and rhythm and slight change in pitch and duration occur. The song is usually given while the bird is hidden within the leafy crown, but it may be given by a bird on a semiopen perch at the top of a bush. It may be given repeatedly from a single perch or as a momentary interruption while a bird is foraging. The singing posture is alert, the head raised, the tail tilted upward. The entire body, especially the throat and tail, vibrates in rhythm with the notes.

The full song is given throughout the entire year and is characteristic of the male. Many times I have identified the member of a marked pair that was singing, and only once was it the female. She gave it a few times while her mate was fighting with a neighboring male. From my experience I believe that, except during a territorial dispute, the bird giving the song may be assumed to be the male. The song appears to have a double purpose. It is used as an announcement of territorial possession. One male sings, a neighbor sings, the first repeats its song, and so on until most males are echoing the song. The male often sings as he advances to drive an intruder out of his territory. It also serves as a call or answer to his mate as will be described below.

What might be considered another variation of the song is actually a distinct call. It is similar to the song in quality, intensity, and pitch, but all the notes of the series are given with the same rhythm, so that it does not end in a trill. As compared with the song, it might be written as pit: pit: pit: pit-: pit: pit: pit. The number of notes in the series is usually I or 8 but may be only 2 or more than 15. The individual notes are sometimes more a pee/ca, pita, or peet, and the intensity is more variable than that of the full song. This call is used mainly by the female but is also used by the male and is a call to the mate. Innumerable times I have heard the full song given first and answered by this one, or the reverse is just as frequent. Often the calls alternate three to six times, or they may even be given simultaneously. Such calls and answers may be heard at any time of day and throughout the year and seem to give the location of one to the other, as one of the birds frequently goes to the other. Sexual excitement may also play a part as variations of these calls, variously recorded during field work as pit-tr-tr-tr-tr, perrrrrrrrt, musical repeated trrrr or weak pit followed by accented trrrrr, are heard on the days when the pair is completing a nest and sexual flight or copulation is taking place, though neither of these acts is invariably accompanied by this song.

Sometimes the response to the loud-ringing call of either the male or female is a faint burring note, lcrrrrrr. This short note is given at intervals as a pair forages and seems to keep the two near together.

A similar but louder accented lcrrrr, often repeated three or four times, is an alarm note. It is given as the bird disappears in the brush when it is startled. It is often given by a trapped bird or by another bird that is circling the trap.

A loud continuous /crrrr that may be kept up for minutes on end is a scolding or mobbing note. At intervals it may be interrupted, only to start again with equal vigor. The bill is held slightly open, and the whole body vibrates as the sound is produced. The bird is in constant motion, shifting from one perch to another and following or circling the disturbing factor, usually a jay. The same note was used to mob a sharp-shinned hawk. Once a snake appeared to be the cause. The same sound was often given when I was near the nest.

A squealing note, sores or sohree, was heard a few times. Three or four times it was given when I reached into a trap to take the bird in my hand or when I was banding it. The same sound was heard during fights between individuals kept in cages, once by a bird fighting bill to bill with another, and once by a male when another attacked it. It appears to be a note of fear, defeat, or submission.

During boundary disputes between established pairs, a series of low staccato notes, which I have recorded as pit’ pit’ pit’, tut’ till’, or peeka, is commonly given, often by several birds at once.

The first songs of the young may have the full ringing quality of the adults, but often they are thin, weak, and tremulous. The trill that terminates it is frequently more prolonged and has a warblerlike quality.

Field marks: An outstanding field character of the wren-tit is its long tail tilted up at an angle from the body, rounded at the tip and narrow at the base. Other characteristics are the general grayish brown of the back and the cinnamon-brown of the underparts, its relatively long legs, the way it remains hidden within the brush, and the fact that two are invariably seen together. If one is near enough the white iris may be seen. The songs and calls are distinctive and easily learned.

Enemies: The destruction of eggs and young by natural causes is high. Of 24 nests found before or soon after the set was completed, young were fledged from only 10. Wren-tits recognize jays as a source of danger to their young, and with reason, for both Mrs. A. S. Allen (MS.) and I have seen the jays take eggs and young from nests. Other enemies of the young and adults are probably those common to most small species. Dr. A. II. Miller found the remains of two wrentits in the pellet of a homed owl.

Fall and winter: As already indicated, the adults remain in pairs on their territories during fall and winter. Their activities continue on a relatively uniform level and serve to maintain themselves, their companionship, and their territory. They are constant companions, forage together, keep track of each other by calls, preen each other, sleep together, and may rarely show sexual excitement to the degree of attempting copulation. They are relatively tolerant of the wandering young and are themselves occasionally found a little distance beyond their usual boundaries, but the male sings regularly and both defend the territory from aggressive invasion.

The young, on the other hand, tend to wander during the early fall. Of 46 banded young reared in the canyon where I watched intensively, only one was seen or trapped after it was nine weeks old, though unbanded immatures were common. One of my banded young when nine weeks old was trapped half a mile from its original home. It is at this time that wren-tits are seen in the shrubbery of dwellings. How far they wander is difficult to say, but I doubt if it is more than ten miles. Soon after this period of wandering, the young tend to remain in one place, usually with a companion of the opposite sex. Sometime in the course of the winter, certainly by March, it ceases to be satisfied with merely a place to forage and a casual companion. If a male, it tries to acquire a territory; if a female, it seeks an unmated male with a territory. Most but not all are successful. Once established it will, usually, survive on its territory for 5 years, but it may persist for as long as 10 years.

DISTRIBUTION
Range: Oregon to Baja California.

The wren-tit is found north to northwestern Oregon (Astoria). East to western Oregon (Astoria, Rogue River Valley, Gold Hill, and Medford) ; central California (Hornbrook; the western slope of the Sierra Nevada, Yosemite, Walker Pass, Kern County, and the San Bernardino Mountains); and Baja California (east base of the Sierra San Pedro M~rtir and Aquaita). South to Baja California about latitude 300 (Aquaito). West to the Pacific Ocean, Baja California (San Quintin, San Ram6n, and San Telmo); California (San Diego, Santa Paula, San Francisco, and Humboldt and Del Norte Counties); Oregon (Newport, Tillamook, and Astoria).

The range as outlined is for the entire species, which has been divided into six subspecies or geographic races. The coast wren-tit (C. f. phaea) is found in the humid coastal region of Oregon from the Columbia River about to the California line; the ruddy wren-tit (C. f. ritfula) occurs in the humid coast belt of California south to San Francisco Bay; the intermediate wren-tit (C. f. intermedia) is found in the San Francisco Bay region, except the coastal strip north of the Golden Gate, south to Santa Clara County; Gambol’s wren-tit (C. f. fasciata) occurs in the coastal strip of Monterey and San Luis Obispo Counties; the pallid wren-tit (C. f. hensliawi) is found from the Rogue River Valley of Jackson County, Oreg., and in the foothills and valleys of interior and southern California, and along the coast from Santa Barbara County to about the Mexican boundary; the San Pedro wrentit (C. f. canicauda) is found in northwestern Baja California, south to about latitude 300.

Casual records: A pair were collected at Klamath Falls, Oreg., on November 7, 1912; an individual was observed in July 1937, 10 miles north of Kelso, Wash.

Egg dates: California: 118 records, March 1 to July 2; 45 records, May 1 to May 22; 35 records, March 10 to April 6.

INTERMEDIATE WREN-TIT
CHAMAEA FASCIATA INTERMEDIA Grinnell
Although this subspecies was originally described and named nearly 50 years ago, it has only recently been recognized in the twentieth supplement to our Check-list (Auk, vol. 63, p. 431, 1940).

Dr. Joseph Grinnell (1900) described it as follows: “Back and upper tail-coverts, sepia, shading into hair brown on nape and top of head. Lores and small spots on upper and lower eye-lids, pale gray. Throat and breast, cinnamon-rufous, fading posteriorly into pale vinaceous-cinnamon on middle of belly. Feathers on breast, with faint dusky shaftstreaks. Sides, flanks and lower tail-coverts, brownish olive. Under wing-coverts and axillars, pale vinaceouscinnamon. Wings and tail, clove-brown, the feathers with slightly paler edgings.’~ This subspecies is clearly intermediate between the dark northern race and the pale southern form. Whether it is wise to recognize intermediate forms in nomenclature is open to serious question. We have no reason to think that it differs materially in any of its habits from other races of the species. Its eggs seem to be indistinguishable from those of the species elsewhere. It has only a limited range in the San Francisco Bay region, except the coastal strip north of the Golden Gate, and southward to Santa Clara County.

PALLID WREN-TIT
CHAMAEA FASCIATA HENSHAWI Ridgway
HABITS

The pallid wren-tit is the most widely distributed race of the species. The 1931 Check-list gives its range as the “Upper Austral Zone of the foothills and valleys of interior and southern California from Shasta County south, and along the coast from Santa Barbara County to the Mexican boundary.”

Living as it does in an arid environment, it is also the palest of the California races. Ridgway (1904) describes it as “similar to C. f. fa8ciata, but decidedly paler, the back, scapulars, rump, etc., grayish brown (deep hair brown), the pileum and hindneck brownish gray (nearly mouse gray or deep smoke gray), and general color of under parts varying from very pale grayish buff to huffy ecru-drab or pale vinaceous-buff, fading to nearly white on lower abdomen.” He remarks in a footnote that “occasional specimens from the southern coast district are nearly as deeply colored beneath as true C. fasciata.”

In spite of its interior habitat, the haunts of this wren-tit seem to be similar to those described under Gambel’s wren-tit, for Grinnell and Storer (1924) write of its haunts in the Yosemite region: “The regular niche of the Pallid Wren-tit is in the foothill chaparral, beneath the crown-foliage of the brush plants and so usually not more than 5 feet from the ground. Fully nine-tenths of the bird’s existence is passed in this shallow zone. Occasionally wren-tits are to be seen up in oaks or other trees growing amid or close to the brush, while now and then a bird will be noted on the ground, momentarily. But the three essentials for the bird’s life, food, shelter from enemies, and safe nesting sites, are afforded in largest measure in the chaparral itself.”

Nesting: The same writers located a nest of this wren-tit 7 feet above the ground, much higher than is usual, “in the spray of terminal foliage of a slanting greasewood stalk.”

Wright M. Pierce (1907) found a nest of the pallid wren-tit in San Antonio Canyon, elevation about 4,500 feet, near Claremont, Calif. He describes it as follows:

It was situated among thick branches and near the top of a scrub oak bush perhaps two and a half feet up, and is a gem of bird workmanship, composed, as it is, of bleached weed fibres such as fine grasses, an ahundance of soft plant down, a little weed bark, and fine hairy threads of bark of the yucca plant, with a few wider blades of grass intermixed and woven about thin tile whole thick-walled structure. A thick mass of horse hair makes the lining. To more firmly bind and hold together the nest, which even without would have been unusually strong and serviceable, these ingenious little birds used cobwebs as an outer covering to make their house doubly strong. The dimensions of the nest are: Depth, oatside, 5 inches; Inside, 2 inches. Diameter, outside, 4 inches; inside, 2 inches.

This seems to be an unusually large nest in outside dimensions.

There are two nests in the Thayer collection in Cambridge, taken near Escondido, that were placed about 2 feet up in sagebushes; fine strips of sage bark and some of the sage blossoms were used in the construction, which must have helped to conceal the nests.

This seems to be the only one of the wren-tits that has been recorded as a victim of the dwarf cowbird; Dr. Friedmann (1934) reports only three cases of such parasitism.

The eggs of the pallid wren-tit are similar to those of the other races of the species. The measurements of 40 eggs average 18.0 by 14.1 millimeters; the eggs showing the four extremes measure 19.4 by 14.3, 18.3 by 14.7, and 16.8 by 13.4 millimeters.

SAN PEDRO WREN-TIT
CHAMAEA FASCIATA CANICAUDA Grinnell and Swarth
HABITS

This is the southernmost of the wren-tits, living in northwestern Baja California, from the United States boundary south to about latitude 30.

In describing this race, Grinnell and Swarth (1926) give, as its distinguishing characters: pale colored as regards plumage, more so even than its nearest geographic relative, henahaw~, hence the palest colored of the forms of ChamaeG fasciata. The differences distinguishing canicauda from henshawi, though slight (hardly appreciable In hadly worn plumage) are, it seems to us, notable in being of a different sort from those distinguishing hen8hawi from C. P. fasciata. In the latter case, while hen~hawi Is much paler than fasciata, they are both ~jrownï tinged hirds. In caaicauda the browns are almost eliminated. The cinnamon of the underparts Is extremely pale, the middle of the belly being nearly white, the upperparts, whole head, wings, and flanks are slaty, while the tail is deep slate. In cankauda the bill and feet are unequivocally black; in all the other laces of Ci&amaea the bill and feet are more or less tinged with hrown: “horn color.”

A. W. Anthony (1893), while exploring the San Pedro M~rtir Mountain, found this wren-tit “common along the lower slopes of the Inountain and not rare in the highest altitudes where it nests in the scrub oak and Manzanita.”

The measurements of 7 eggs in the P. B. Philipp collection average 18.5 by 14.3 millimeters; the eggs Showing the four extremes measure 20.4 by 14.0, 17.6 by 14.8, and 17.3 by 14.2 millimeters.