PALLID WREN-TIT. Chamaea fasciata henshawi Ridgway

Field characters.—Size nearly that of Junco; tail long, exceeding body in length, slender, rounded at end, and habitually carried up at decided angle with back. Coloration grayish brown above, pale brown beneath; iris white. Voice: Common call a series of clear whistled notes all on nearly or quite the same pitch, uttered slowly at first then more rapidly, running into a trill, pit, pit, pit, pit-tr-r-r-r-r; also a subdued, ratchet-like note, repeated in series.

Occurrence.—Common resident on west slope of Sierra Nevada in Upper Sonoran Zone. Recorded from Pleasant Valley eastward to El Portal and to Smith Creek, 6 miles east of Coulterville. During late summer and through the autumn a few individuals range eastward into Transition Zone as along walls of Yosemite Valley to head of Nevada Falls and to Tenaya Cañon above Mirror Lake. Lives mostly in chaparral, sometimes foraging in low trees and occasionally on the ground. Usually in pairs.

The wren-tit is a species peculiar to western North America, and is further limited practically to California; indeed, it does not, as do so many western birds, even have a counterpart in the eastern states. The light-colored race, the Pallid Wren-tit, inhabits the chaparral belt in the western foothills of the Yosemite region and at certain times of the year invades the mountains as far as Yosemite Valley. The wren-tit, as its name indicates, displays some obvious degree of likeness to both wrens and "tits"; yet it stands so far apart from both of these groups as not to be classified with either of them, save in a very broad way.

The most outstanding feature in the wren-tit's make-up is its long and slender tail which is longer than the body of the bird, rounded at the end, and habitually carried up at a considerable angle with the back. This character alone will usually be sufficient to distinguish the wren-tit from all other local species. The wings are short and rounded, a shape which usually goes with a long tail in birds which inhabit shrubbery. The plumage is plain, grayish brown above and somewhat paler beneath, and the body feathers are very soft and lax in texture. At close range the white iris is evident and furthermore, one may then sometimes make out an inconspicuous dusky streaking on the throat and chest.

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 five 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.

Wren-tits go about regularly in pairs in winter as well as during the nesting season. The young after leaving the nest accompany their parents for a time and so four or five birds may be seen together. Occasionally during the winter months loosely formed assemblages of six or eight are noted. Wren-tits are wont to gather quickly about any disturbance in the brush, but they disperse as soon as their curiosity is satisfied or the cause of their concern disappears. In ordinary behavior they are sober, dignified in manner, evincing little or no nervousness such as characterizes the wrens.

In the matter of voice the Pallid Wren-tit differs from most other small birds in that both sexes utter all of the notes characteristic of the species. Furthermore, the birds give their calls throughout the year, with little cessation during the time of the annual molt, and with little if any increase in vocal effort in the courting and nesting season. So far as known, none of the various calls is restricted to use at nesting time; any or all may be heard in fall or winter as well. The most commonly heard utterance, possibly the 'song' of the wren-tit, is a series of whistled notes, all on nearly the same pitch, begun slowly and distinctly, then becoming more rapid, and going into a trill which is ended abruptly: pit, pit, pit, pit-r-r-r-r-r. This call carries well and may be heard easily when the listener is a quarter of a mile or more distant from the bird. Sometimes the notes are given slowly without being run together at the last—pit, pit, pit, pit, etc. Occasionally there is heard a series similar in timing to the second, but of different quality—in what might be called a complaining tone—keer, keer, keer, keer, etc. There is also a low, ratchet-like note, sometimes interrupted, again given continuously for several seconds, but never so loud as to be audible more than a few yards away. This is uttered when a pair or group of birds is investigating any unusual occurrence in the brush.

At nesting time the wren-tits are extremely localized, each pair keeping within a small area, of which the nest is the pivotal point. The nest is a small structure only three or four inches in diameter and the same in height and is seldom easy to find amid the many dense tufts of leaves and small branches in the chaparral. The location of one nest, in grease-wood brush on the hills a mile west of Coulterville on May 11, 1919, required an hour and a half of intensive search. The details of the manner of finding this nest will, perhaps, be of significance.

When the observer followed up a bird which was calling, it was found to stay in a certain tract about 200 feet square covered with tall grease-wood and scattered small live oaks and toyon bushes. Part of the time two wren-tits could be noted and one of them, which acted somewhat concerned, kept appearing and disappearing. Then the observer began a systematic search, crawling back and forth beneath the brush. After some little time one of the wren-tits came very close, uttering its low 'ratchety, screeping' note at intervals, and thereafter kept close watch, at times coming within six feet of the observer and gazing at him intently with one or the other of her (?) white eyes. The bird continued to move about, now in the brush, then on the ground, in the latter case standing high on her long legs with tail up at a sharp angle to the back. She kept taking in worms (moth larvae), giving each fresh captive a thorough battering on some dead stick and then stuffing it with preceding ones into her bill and throat. Soon she had a mass of these protruding from either side of the bill; but still she failed to go to her nest. The other member of the pair (presumed to be the male) came near once or twice but soon went off again and called in usual wren-tit manner fifty yards or more away. The bird with worms in the bill called occasionally in slower cadence, but with the same distinctive quality to the utterance, it being in no wise muffled by her mouthful. Every bit of the ground adjacent was searched carefully and then the observer turned and gave similar attention to the canopy of brush above him, which showed many small dark masses against the sky. Finally the nest was located, merely a dark spot in the uppermost Adenostoma foliage, 7 feet above the ground, much higher than is usual for the nest of this species.

The nest was of globular form, thin-walled but deeply cupped, made of fine grayish vegetable substances which were bound together with cobwebs. It rested in the spray of terminal foliage of a slanting greasewood stalk. There were three unfeathered young, and it was for these that the female had been gathering food and showing such cautious concern.

Through the nesting season and until late June or early July all of the wren-tits keep to their foothill haunts. But as soon as the young are fully fledged some of the birds commence to wander and a few range well beyond the limits of their home precincts. In all probability these strays are young-of-the-year as is the case with most other species given to vagrant travel in the late summer months. Our earliest record for a wren-tit above the Upper Sonoran Zone is for July 21 (1915) when one bird was heard near Cascades. On July 30 (the same year) 2 were heard near Rocky Point in Yosemite Valley; on August 17 one was noted near the same place; while on September 1 at least 2 were in evidence near the head of Nevada Falls. This last-named station and the walls of Tenaya Cañon at about the same altitude (6000 feet) seem to mark the eastern limit of the 'wander' zone; at least no wren-tit was seen by us beyond these places. The birds continue to occupy the brush thickets on the Valley wall through September and even to the end of October, two being noted October 30, 1915, high on the Yosemite Falls trail. And even on December 30, 1914, one or more wren-tits were noted close to 'old' Inspiration Point (4943 feet altitude) on the Big Oak Flat road. By spring if not earlier, the species has entirely withdrawn to the foothills.

The aggregate wren-tit population of the whole foothill country with its thousands of acres of chaparral is very large. Yet the birds are so spaced that their numbers are not so impressive as are those of a flocking species. Every little cañon has its pair or more of the birds. At Pleasant Valley in May, before the appearance of the annual broods, it was estimated that there was a pair of wren-tits to every 4 acres of greasewood. In early winter on the south-facing slope above El Portal 6 to 9 wren-tits were recorded for each hour of observation, the birds being in pairs and groups of 3 and 4.

The wren-tit is chiefly an insectivorous species although at times it takes food of a vegetable nature. Insects certainly predominate in the diet during the summer season, and on this sort of material, as indicated above, the young are probably exclusively fed. In fall and winter, berries are eaten to some extent. At the Campbell ranch north of Pleasant Valley several wren-tits were feeding, in company with hermit thrushes, upon berries of the toyon, and others were seen pecking at some old figs which had dried up on the trees.