INTERIOR CALIFORNIA JAY. Aphelocoma californica immanis Grinnell

Field characters.—Body size about that of Robin but tail longer (as long as body), broader, and rounded at end. No crest on head. Top of head, neck, wings, and tail, blue; back grayish brown; under surface of body grayish white, except for incomplete collar of blue low on breast. Voice: A variety of mildly harsh notes: kwish, cheek, chu'-ick, schwee-ick, kschu-ee; young out of nest utter a "teasing scold."

Occurrence.—Abundant resident of Upper Sonoran Zone on west side of Sierra Nevada. Ranges locally down into Lower Sonoran Zone (as at Snelling) and up into Transition Zone (as at Dudley). Reported in Yosemite Valley (near Lost Arrow Camp), September 25, 1917 (Mailliard, 1918, p. 18), and on several dates in 1920 between July 26 and September 11 (C. W. Michael, MS). Frequents blue and live oaks, digger pines, and chaparral. Non-flocking, but socially inclined.

The Interior California Jay is a characteristic inhabitant of the oak, digger pine, and chaparral growths which clothe the slopes of the foothills flanking the west base of the Sierra Nevada. Only locally does it invade the Great Central Valley below and to the west, or the pine covered slopes of higher elevation immediately to the east. Beyond the Sierras, in the vicinity of Mono Lake, its niche is taken by a closely similar species, the Woodhouse Jay. Within most of its range as thus circumscribed it is the only bird of its family and is abundant there at all times of the year.

Whoever chances to invade the domain of the Interior California Jay will speedily make the acquaintance of the bird, for it is quick to sense the arrival of a newcomer within its range and it promptly makes an investigation of the traveler's business. The large size of the bird and the clear blue of the head, wings, and tail readily identify it as a blue jay, while the grayish white color of the under surface mark it as different from the Piñon Jay which may sometimes visit the western foothills. This gray under surface, the paler blue of the upper parts, and the absence of any sort of crest, all combine to make the California Jay easily distinguishable from the Blue-fronted Jay.

The normal habitat of this species is the foothill oak belt; in the oak trees the jays find everything necessary for their existence, food, shelter for their nests, and retreats for themselves and young. They are found also, however, to some extent in other kinds of trees, and also locally in tracts of pure chaparral. Finding such complete satisfaction of all its life requirements within one relatively narrow zone, it is not surprising that the California Jay is a permanent resident. It does not participate, at least to any appreciable extent, in the late summer, up-mountain, food-seeking migration undertaken by so many foothill birds, the bush-tits, the wren-tits, etc., species which are also ordinarily classed as residents. On a few occasions individuals have been found in Yosemite Valley, though our own party did not happen to see any there. On September 25, 1917, Mr. Joseph Mailliard (1918, p. 18) noted a bird near Lost Arrow Camp. In 1920 Mr. C. W. Michael (MS) noted the species on July 26 and 29, and on several dates in August and September until the 11th of the latter month, ten of the birds being seen on August 27.

The Interior California Jay is notoriously bold and forward in its behavior; although it is counted as a non-flocking species, individuals and pairs will gather quickly in response to the excited calls of one of their kin. The birds seem never to be so busy with their own affairs that they cannot stop and investigate any object of an unusual nature. Ordinarily this jay is the picture of animation. Perched, it stands in an attitude of alertness, its head up, tail straight back or tilted slightly upward, and feet slightly spread. Just after alighting a jay will often execute a deep bow involving the entire body, and this may be repeated a number of times and in different directions. The purpose of this bowing is not clear to us. Leaving a perch in the top of one tree the bird will often fly to another of equal elevation, keeping on a direct and nearly level course high in the air during its passage between the two vantage points. Its flight is characteristic, a few strokes of the short rounded wings, then a sail, while from time to time the tail is spread so that its rounded end and kite-shaped outline show well. Descending from the top of a tree to the ground a jay will sometimes drop at a steep angle, with wings and tail closed, only opening them momentarily to check or guide its passage.

If interest lags the jay will seek a perch at the top of an oak or digger pine, and sit there silent and motionless for minutes at a time, with its tail hanging like a dead weight, vertically downward. But the bird evidently watches all that goes on in the vicinity, for it frequently comes out of one of these reveries with a sudden burst of voice and movement.

When going down to water to drink the behavior of the California Jay is in marked contrast to that of most birds. The jays waste no time in looking about for possible enemies; they probably fear none. The two birds of a pair watched near Coulterville came down to the stream one after the other and each drank three or four times, tipping the head back with each swallow.

The voice of the California Jay, although considerably varied, is easily recognized and remembered after once learned, but we find it difficult to describe intelligibly. To one of the present authors (Grinnell) some of the more common notes seem possible of representation as follows: cheek, cheek, cheek, etc., staccato, 3 to 10 times in rapid succession; chu'-ick, chu'-ick, chu'-ick, etc., usually in 3's, slowly; schwee-ick, higher-pitched, 2 to 6 times, uttered still more slowly. To the other author (Storer) the following transcriptions seem to represent the notes most often heard: (1) A series of mildly harsh notes, kwish, kwish, kwish, uttered usually 3 to 5 times in quick succession; (2) a more protracted softer note, kschu-ee, or jai-e, usually given singly. Birds of a pair when foraging together, and young and adults when in family parties, utter a subdued guttural krr'r'r'r'r. When attending young still in the nest, the parent birds utter a low crooning, impossible of representation in syllables; and the young birds, after leaving the nest and before gaining their living independently, have a "teasing scold" which they utter almost incessantly, in keeping their parents apprised of their need for food. Most or all of the above notes are uttered with various modifications, perhaps to indicate different shades of meaning. As is true of some other members of its family the California Jay employs a 'language' which it probably finds of considerable usefulness.

With the coming of early spring, the instincts which accompany the nesting season are revived and the jays commence the construction of their nests. Building, in some instances, probably begins in April, as by early May nests with eggs or young are common. Young birds, out of the nests, were seen in the third week of May, 1915; while at the same time a pair of adults was seen constructing a nest. All broods are not brought off at the same time. Our findings may be given in some detail here to present a more complete record of the nesting of the California Jay in the Yosemite region.

A nest with 4 nearly fresh eggs was found near Lagrange on May 8 (1919). On May 10, that year, a nest with one young bird and the other eggs on the point of hatching was seen near Coulterville. On May 21 (1915) a nest was found under construction near Pleasant Valley, and on May 23 young were heard, out of the nest, near the same place; while on May 30 an adult with 3 young scarcely able to fly was seen there, and on June 3, a family party of 4 of these jays was seen near the McCarthy ranch, 3 miles east of Coulterville. The young birds remain with their parents for a long time, even into August, and so have a long period of dependence or semi-dependence. After that the individuals or pairs scatter out everywhere through the oak covered regions.

The nest mentioned above as found near Lagrange on May 8, 1919, was in a blue oak on the crown of a rounded hill overlooking the Tuolumne River. The rim of the nest was by actual measurement 4780 millimeters (about 16 feet) from the ground, and was at the side of a horizontal branch 80 millimeters in diameter where some small twigs formed a 5-sided frame into which the nest was set. The foundation work of the nest was about 200 millimeters across, and consisted of crooked dry blue oak twigs. There were large interstices in the weaving. Inside of this was an intermediate layer of dry fine yellow grass stems and rootlets. And within this was a thin lining of black horsehair forming an inner cup. The latter was 100 millimeters in diameter at the top and 50 millimeters deep at the center. The four eggs lay on this inner lining. One of the parent jays had been sitting on the nest, which was readily visible from anywhere within a 50-foot radius of the tree; but the bird flushed at our approach and did not again come within a hundred yards of the site while we were there, although both members of the pair called from a distance several times.

Soon after arriving at Blacks Creek, west of Coulterville, in 1919, we discovered a California Jay's nest in the crotch of a willow which leaned over the creek directly opposite where we had made our camp, and not over 30 feet from the tent door. During the succeeding days we had many opportunities to observe the behavior of the parent birds. When one of us climbed to the nest on May 10, it was found to contain one newly hatched youngster and 3 eggs ready to hatch. The sitting bird had remained until closely approached. It then flushed quietly and returned as soon as the observer quitted the tree. The mate was seen only momentarily on this occasion. The remaining eggs evidently hatched on that day or the next, as the adults had by that time begun to busy themselves in obtaining food and bringing it to the nest.

The parent birds had a particular route in approaching and leaving the nest, and this route was adhered to strictly. They would always approach through the trees of a wooded slope to the east, and then, having reached the nest tree, hop by easy stages to a position on the west side of the nest. From there the nestlings would be fed, and then the nest cleaned. After that the bird would work out of the south side of the willow, fly to a digger pine across the creek immediately above our tent, hop upward until near the top of the pine, and from there would take off in a direct course to its next forage ground. Even when the jays had been hunting insects in the open area immediately west of our camp, they would circle about when ready to return to the nest and approach it from the east. Only one adult visited the nest at a time although they often followed one another in quick succession. Save for the low crooning given when standing over the young, no calls were uttered while the parents were in the vicinity of the nest. There was a 'zone of quiet' about their home, within which the owners would not call or raise any alarm.

The California Jay shares with others of its tribe the reputation of a plunderer of the nests of other birds. Both eggs and young are taken in season, but usually the jays' persecution of the smaller species ends by late summer. Mr. Donald D. McLean has told us, however, that on one occasion in midwinter he saw a California Jay kill a Sierra Junco. While near Coulterville we heard and saw several demonstrations by suspicious small birds caused by the presence of jays near the small birds' nests. One jay seen hopping about in some hillside brush caused consternation among some wren-tits and gnatcatchers which evidently had nesting interests there. On another occasion a California Jay was seen to enter a small blue oak and by a few vigorous hops ascend to the top of the tree where it perched in silence. Upon its arrival, a pair of Western Gnat-catchers which had been in the same tree left off their foraging, and the male of the pair began to swing in vertical pendulum-like arcs over the jay's head, coming within 6 inches at each swoop and rising 2 or 3 feet on either side. No note was uttered by either bird. The performance evidently discomfited the jay to some extent, for it soon began to move. For a while the gnatcatcher followed, continuing his swinging course. The jay's passage from tree to tree was marked for some distance by the movements of its demonstrative satellite. Eventually the jay made off in rapid course and left its small tormentor behind. On another occasion a California Jay seen on the ground in search of insects was the center of a similar but shorter demonstration by a Western Kingbird.

The California Jay is surprisingly adaptable as regards its food habits and yet it depends very largely upon a certain few items. In the nesting season various insects are gathered in quantity, together with such eggs and young of the smaller birds as opportunity offers. But the staple diet of the species, during the interval between the close of one nesting season and the beginning of the next, is derived from its favorite tree, the oak. At El Portal in the fall months California Jays were seen on several occasions carrying acorns in their bills. At times they would obtain the nuts from the golden oaks on the south side of the river cañon, and then fly across the river, high overhead, each bird carrying one acorn lengthwise in its bill. They flew eventually to the dry brush-covered slopes which clothe the north wall of the cañon, and there, as was seen in several instances, the acorns were buried, singly, in the ground. With vigorous blows of the stout bill a jay would quickly excavate a steep-sided pit into which he would thrust the nut, cover it over, and tamp the ground. Sometimes leaves would be whisked over the spot, with evident intent to render the place indistinguishable from the surrounding surface of the ground. There is no doubt that the jays themselves fail to recover many of these caches, and thus unconsciously, as planters of seeds, serve the interests of the trees.