BLUE-FRONTED JAY. Cyanocitta stelleri frontalis (Ridgway)

Field characters.—Somewhat larger than Robin. Head with a conspicuous crest; tail as long as body, broad, and slightly rounded at end; wings short and rounded. Head (including crest) and forepart of body, blackish; wings, tail, and hinder part of body, chiefly deep blue. Young more blackish, less blue, especially on lower surface, and plumage more fluffy. Voice: Extremely varied (see below); usual calls harsh and loud, ksch, kschak, or glook, in series of three.

Occurrence.—Common resident of Transition and Canadian zones on west slope of Sierra Nevada and of Canadian Zone on east slope. Recorded from Smith Creek (east of Coulterville) and Feliciana Mountain, east to Lake Tenaya and Lake Merced; also from cañon of Leevining Creek opposite Warren Fork east to Williams Butte. A partial vertical migration to lower altitudes (as to El Portal and even Pleasant Valley) occurs in at least some winters. Remains in Yosemite Valley throughout the year. Frequents wooded territories; seldom descends to ground. Non-flocking, but individuals quickly assemble about any object or sound which incites their curiosity.

The Blue-fronted Jay is the Sierra Nevadan representative of the Steller or crested jays, a wide-ranging group found throughout most of the mountainous regions of western north and middle America. Blue jays, of any species, by reason of their large size, loud voices, and bold manners, bring themselves quickly to the attention of all who visit their haunts, and this is eminently true of the subject of the present account. Locally the Blue-fronted Jay is known as the "mountain blue jay" because of its restriction to the higher altitudes, and to distinguish it from the California, Woodhouse, and Piñon jays found in the lower country on either side of the mountains. The name 'blue-fronted,' designating this particular jay, refers to the streaks of light blue which face the crest in front, that is, just above the base of the bill. This color mark is not conspicuous enough, however, to serve as a mark for field identification.

The Blue-fronted Jay inhabits both the Transition and Canadian zones. On the west slope its range meets that of the crestless or flat-headed California Jay where the main forest belt of the mountains proper gives way to the foothill oaks and chaparral. In a few places along this line or belt of contact these two jays are found together; but each keeps as a rule to its special niche, the Blue-fronted to the pines, the California to the live oaks and blue oaks. Upward, the range of the Blue-fronted ends abruptly at the Canadian-Hudsonian boundary, above which is found the Clark Nutcracker. On the east slope of the mountains, in the Yosemite region, the Blue-fronted Jay is found only in the Canadian Zone. The Transition Zone of the arid interior lacks at this latitude any extensive growth of forest trees, and this fact probably accounts for the absence of Blue-fronted Jays from that part of the Transition Zone.

As a species the Blue-fronted Jay occupies the range outlined above throughout the year, but with the coming of winter there is a down-mountain movement (altitudinal migration) which carries a portion of the jay population to lower zones. This has been observed on the west slope of the Sierras and may occur on the cast side as well. At El Portal, on November 28, 1914, an influx of Blue-fronted Jays was observed immediately following the first fall of snow for the season on the adjacent higher ridges. In 1915, on December 8, Blue-fronted Jays suddenly appeared at Pleasant Valley. The jays stayed there "through the winter" according to local testimony, but were gone by the end of February. Mr. Donald D. McLean has told us that a certain number of these jays regularly drop to below Coulterville for the winter months. In certain winters, presumably those marked by severe storms in the mountains Blue-fronted Jays have migrated down even into the San Joaquin Valley, for instance, to Stockton. It seems likely that difficulty in getting adequate food is a more important factor in influencing this semi-migration than unfavorable weather, especially since a certain number of the jays seem to find no inconvenience in remaining in the higher zones throughout the winter season.

During the nesting season the jays are to be seen in devoted pairs, and after the broods leave the nest the fullgrown young and their parents remain for a time in family parties. With the coming of fall, the parental and filial instincts wane, these family parties break up, and the individuals scatter out rather uniformly through the forest. But the jays retain a strong social sympathy which causes the separated birds to quickly congregate about any object or sound which excites their curiosity. In mid-winter, even this interest decreases and the jays then seem to pay little attention to contemporary events, unless food be involved. Heightened curiosity is, for birds in general, an accessory of the nesting season when danger, apparent or real, threatening either the nest or brood, must be guarded against. At the opposite season, midwinter, when nesting instincts are at their lowest ebb, curiosity also lags. Self-preservation is then the important factor. But even putting this seasonal variation aside, Blue-fronted Jays show marked interest in most of the events which take place about them. Often when the observer is seeking one of the rarer or more reclusive birds or mammals of the forest, his cautious stalking comes to naught because of the blatant squawking of one of these garrulous informers. In our own case, frustration of our original purpose has more than once resulted in our pointed attention being directed toward the disturbing jay!

The Blue-fronted Jay spends much the greater part of its time in the trees; it does not forage extensively on the ground as does the California Jay. A favorite perch is near the top of a tall tree where it can command a wide range of vision and hence see all that goes on in the forest. Ascending a tree it is wont to keep close to the trunk and hop upward from one limb to another, assisted occasionally by a flutter of the wings. At times a bird will ascend one tree, then sail down on spread wings and tail to the bottom of an adjacent tree and from there repeat the performance. Such actions are usually accompanied by certain of the harsh scolding calls described later. This trait of keeping close to the trunk, "like following a spiral staircase" as one observer has expressed it, makes the birds difficult to watch during the nesting season when they are endeavoring to avoid being seen. At such times they often run along lengthwise on the branches in furtherance of their attempts to elude observation. A mannerism of the bird which particularly impresses the observer at times is its turning the head abruptly this way or that while looking about; in so doing its tall pointed crest is switched from side to side so that the presence of this adornment is emphasized.

The jays are closely related to the crows and share with those birds the possession of an elaborate vocabulary. A commonly heard call of the Blue-fronted Jay is a series of harsh staccato notes variously rendered chuck, chuck, chuck, or quick, quick, quick, or kschak, kschak, kschak, given in quick succession and usually uttered as the jay flies off, on spread wings and tail, and sails into the shelter of a neighboring tree. Then there is a softer though yet harsh, more slowly enunciated, scolding ksch, ksch, ksch, or kwisch, kwisch, kwisch, given three or more times while a jay is perched or hopping upward in a tree. Again there is a deeper, hollow toned or wooden, glook, glook, glook. Occasionally a jay will take position in dense foliage and then utter a clear, whistled skwee-oo, resembling the cry of a Red-tailed Hawk as heard at a distance. Under similar circumstances we have heard two other, weird notes, which, since we are unable to express them in syllables or to imitate them, we must merely designate as the 'dry-pump' note, and the 'wheelbarrow' note. A modification of the ksch note leads to kschuey, more prolonged and more often uttered singly than in series of three. When two jays of a pair are hunting close together a low crackling or growling ker'r'r'r'r is uttered. This cannot be heard at any distance and seems to be used most frequently during the nesting season. All these calls are uttered with modifications and different intonations so that a great variety of sound results. It is known that Blue Jays occasionally give a low but musical song and also that at least some individuals can imitate other birds besides hawks. It seems likely, therefore, that these birds are able to comment intelligibly to one another on many different experiences and situations. Here, in this, one of the 'highest' of the birds, we find that a 'language' has been evolved, doubtless to the increased advantage of the species.

Blue-fronted Jays are omnivorous, in that they take any and all kinds of food that the season or place may afford. Camp scraps, bread, fruit, etc., are eaten more or less readily, and pieces of fresh meat are always in demand. An adult male shot on the East Fork of Indian Cañon above Yosemite Valley on June 25, 1915, had its mouth and throat filled with beetles. Two Blue-fronted Jays seen in golden oaks near Yosemite Point on November 19, 1915, along with Band-tailed Pigeons and California Gray Squirrels, were evidently feeding on acorns. The latter source is doubtless a mainstay, resorted to when more desirable food fails.

An interesting habit of the Blue-fronted Jay in hiding food material has been recorded by Dr. Barton Warren Evermann (1915a, p. 58). While his party was eating lunch at Happy Isles on July 12, 1914, one of these jays came down close in quest of food. Bits of cracker were thrown to the bird one at a time. One of these was carried off into the forest, another was eaten, and a third piece was carried to a neighboring incense cedar. This piece the jay wedged and drove into a crevice in the bark and then stripped off several small pieces of bark and placed them in the crack so as to conceal effectively the piece of cracker. The habit recalls that of the California Jay in burying acorns and other bits of provender in the ground.

Enemies of the Blue-fronted Jay do not seem to be numerous. We have already related, in the chapter on the Sharp-shinned Hawk, an encounter between one of those birds and a jay. Mr. Donald D. McLean says that this hawk is the principal enemy of the Blue-fronted Jay at his place east of Coulterville.

No bird in the assemblage of forest-inhabiting species is more secretive with regard to its nesting activities than the Blue-fronted Jay. During the whole of this season, all the artfulness of which the jay is capable is devoted to keeping secret the location of its nest. The structure, although large, as are the nests of most birds of this family, is often hidden in a dense growth of vegetation. And the greatest stealth is observed by the jay in gathering and carrying nest material and in approaching or leaving the site, no matter whether the nest is only under construction or contains eggs or young. No notes are uttered within the immediate environs of a nest and so upon hearing a jay call during the late spring or early summer, one may know at once that the bird is not at its nest.

In the Yosemite region the nesting season of this species begins in April or early May and lasts until July. The nest with young, found on May 18, 1919 (see below), must have been begun in late April. The numerous foraging expeditions of the Blue-fronted Jays during June, as announced by the commotions among small birds heard during that month, probably meant that the jays had young at that time, as did the finding of a mass of insects in the throat of an adult jay taken on June 25, 1915. In Yosemite Valley, on June 27, 1915, a family of these birds was seen, the young still being attended by their parents. Only two nests of this jay came to our immediate attention.

On the road between "Kenneyville" and Mirror Lake in Yosemite Valley, on May 22, 1919, a pair of Blue-fronted Jays was come upon in the act of gathering material for their nest. Several people had camps on the ground about what proved to be the nest tree, so that the jays did not in this instance seem to mind the presence of an observer and they were watched for some minutes. One of the jays was seen to fly into a black oak, obtain a twig, and carry it off, upward, through the adjacent trees to the nest site, at the top of a yellow pine, fully 40 feet above the ground. Then the other member of the pair came, broke off a twig, dropped it, evidently by accident, and sought another. This bird seemed more particular and hopped about the tree for some time before choosing another twig. Pieces dry enough to break off readily, and a little longer than the jay's body, were chosen, and twisted off by a wrench with the bill. The twig would be worked along between the mandibles until held across the middle and then the jay would ascend by the usual vertical hopping and short flights to the nest. Following the taking of black oak twigs the two jays, together, flew across the river which flowed close by the nest tree, and there, descending quickly to the ground, sought material in an azalea thicket at the edge of the water. Each took a quantity of twigs and grass and apparently also some mud, and flew again to the nest tree. Again they took twigs from the black oak. From this alternate selection of twigs and muddy material it was inferred that the nest was well under way. The jays were not heard to call within 150 feet of the nest tree. One was seen, after depositing material at the nest site, to sail monoplane-like off through the trees, calling only after the nest was well behind.

On May 18, 1919, careful search through a thicket of young pine trees on the floor of Yosemite Valley in the vicinity of Rocky Point led to the discovery of an occupied nest of the Blue-fronted Jay. The nest was in a small yellow pine which stood at the edge of the thicket bordering a clearing which opened onto the Merced River about 30 yards off. The rim of the nest was 2700 millimeters (8 feet 10 inches) above the ground, and the structure was on the south side of the trunk resting on three small branches of the whorl which at that height emanated from the trunk. The nest, when once located, was easily seen on the open side even from a distance. It was a bulky affair, decidedly larger than the usual Robin's nest. It was solid in construction, with a large external basal framework of dead and more or less weathered twigs of irregular shape and small diameter (2 millimeters or less). Many of these were black oak twigs while others were of a very furry herbaceous plant. All of the material of this outer framework, as was attested by the clean, fresh-appearing ends of the pieces, had been freshly broken off by the jays. This suggests that, save for the small amount of herbaceous material, all the outer constituents were gathered above the ground. The outside framework measured about 300 millimeters (12 inches) in one direction and 400 millimeters (16 inches) in the other.

The inner cup of this nest was composed of dry needles of the yellow pine, held together by enough mud to give the structure a firm resistant feel. The mud, however, did not extend to the inner surface. The interior of the cup consisted solely of pine needles, which crossed and recrossed so as to make a porous interior lining. This cup was 100 millimeters (4 inches) in diameter at the rim and 68 millimeters (2-5/8 inches) deep at the center. Both the nest and the ground beneath were entirely clean of excrement.

The nest held three young, nearly naked, and hence not over 3 or 4 days old. An adult jay had been covering the young, but flushed at the observer's near approach. The bird slipped off quietly to an adjacent tree and there struck a dumb, statuesque pose which was maintained for a minute or so until the observer showed obvious interest in the nest. Then the bird set up the usual call, ksch or kschuey, repeated over and over again. This brought another jay, presumably the mate (the two sexes are exactly alike save that the female is very slightly the smaller), and soon afterward two others. All four joined in the vocal demonstration. When the jays first set up their calls, two California Gray Squirrels, a Sierra Chickaree, and a pair of Spurred Towhees began to call, but these all quieted down after a time. When the nest was removed from the tree for closer study the four demonstrative jays came close about and called in raucous chorus, but after a while they began to move away and changed their calls to the more wooden-sounding type of note. Thus the Blue-fronted Jay exhibits a marked concern over the disturbance of its own home.

It remains to tell the jay's relation to other birds at this season. Bird students have for years known that the Blue-fronted Jay, like its lowland counterpart, the California Jay, is a merciless plunderer of the nests of small birds. And the small birds have known this, evidently for generations, because they almost universally announce with unmistakable tones of anxiety the presence of a Blue-fronted Jay near their nests. The period during which this instinct of blue jays is exercised coincides of course with the nesting season, when eggs or young of the other birds are available and when the jays themselves have broods or mates to feed. At other times of the year the jay and its smaller relatives live in peace. We, ourselves, while in the Yosemite region, did not chance to see one actual instance of plundering by this jay; such observations can come but rarely even to a person on the lookout for them. But we have observed cases elsewhere, and we know of many reliable reports of the depredations of this jay. We saw evidence of a circumstantial nature, and some of this is worth while relating.

In Yosemite Valley on June 1, 1915, our attention was attracted to a Blue-fronted Jay which was beset by an angry Western Warbling Vireo and then by a Cassin Vireo in similar mood. Each evidently suspected the jay of sinister intention and each in turn endeavored to drive the larger bird away. At Chinquapin, on June 14, 1915, two Red-breasted Nuthatches were heard calling wa, wa, wa, in excited tones. Following up the noise, we found their attention to be centered on a pair of Blue-fronted Jays. The latter were perfectly quiet, a mannerism for which the marauders are noted when on their plundering expeditions. On the same day a Ruby-crowned Kinglet was heard calling its yer-rup, yer-rup, yer-rup, over and over again in low but insistent tones. It, too, was concerned over a pair of the silent but insidious jays. When one of the latter was shot the kinglet immediately broke into song! At Mono Meadow on June 22 some anxious bird notes were heard coming from the top of a lofty red fir. These, again, proved to be due to the presence of a pair of Blue-fronted Jays in the neighborhood. In this instance there were at least 11 small birds at the scene of the disturbance. A pair of Western Warbling Vireos seemed to be the ones most intimately concerned and their calls had evidently attracted the other birds to the site. "Those present" in addition to the vireos were two Wright Flycatchers, two Western Tanagers, two Audubon Warblers, a Red-breasted Nuthatch, and two Ruby-crowned Kinglets. All were contributing their voices to the clamor of remonstrance against the jays. Near Bower Cave, on May 13, 1919, a pair of Willow Woodpeckers was seen mobbing a pair of Blue-fronted Jays, while a California Woodpecker offered half-hearted sympathy. The first-named were uttering in monotonous succession their high-pitched call notes.

Because of the depredations of the Blue-fronted Jay among the smaller song birds of the Park, the rangers, under the direction of the Park Superintendent, have, for a number of years, carried on a campaign for the reduction of the Blue-fronted Jay, more particularly in the Yosemite Valley itself. Sixty-seven jays were killed in the midwinter of 1915-16, in the vicinity of the government stables where they kept drifting in after the arrival of the winter snow. A 3-hour census by the junior author in this neighborhood a little later the same winter (February 28, 1916) did not reveal the presence of a single jay there; in fact none was seen on the floor of the Valley during a three day visit at that season. But by the end of April the same year jays were again present in fair numbers. And three years later, in 1919, even though the campaign against these birds had been continued with greater or less persistency during the intervening period, we could not see that their numbers on the floor of Yosemite Valley were below normal.

Some figures, even though somewhat speculative, will be suggestive here. The floor of Yosemite Valley, counting the area below the 5000-foot contour, contains roughly 10 square miles. Upon the basis of our many censuses, we estimate the jay population in early spring, before the advent of the new broods, to be 32 birds to a square mile, or a total of 320 jays for the area in question. This, be it noted, is the population at the time of year when the numbers have been reduced by various natural causes to the lowest figure. With the breeding season, assuming that each pair of adults successfully rears three young, the jay population jumps to 80 a square mile, or 800 for the Valley, an increase of 250 per cent! Because the surrounding territory was a reservoir of reserve jay stock, depletion of the jay population locally on the floor of the Valley, in the campaign described above, was quickly followed by a 'spilling in' of birds from the flats adjacent and the slopes above. The pressure of competition for food between the individuals of the species serves under normal conditions to keep the birds spaced out rather uniformly. Whenever the population is suddenly reduced in one particular place, birds from the surrounding territory, beginning to feel the release of pressure, work in, and soon fill the vacancy. The process is somewhat analogous to bailing grain out of a bin; the 'hole' is quickly filled up.

However much we may deplore the ravages of these jays among the woodland songsters, it seems unlikely that any great or permanent reduction in the numbers of the former can be accomplished through human agency, commensurate, at least, with the cost involved. The species is well able to recover quickly from any local reduction, as has been shown so well in Yosemite Valley. The Blue-fronted Jay is resident over a large stretch of territory but sparsely occupied by man; it soon becomes 'gun wise'; and it is very secretive in its nesting habits. All these factors appeal to us as making reduction hopelessly difficult. Furthermore, the sizes of the broods of the small birds were probably long ago adjusted to the toll taken annually by the jays. Plundering the nest of almost any bird, large or small, early in the nesting season, will be quickly followed by the building of a new nest and the laying of another set of eggs. So that loss once sustained need not mark the total failure of any particular bird pair for the season. In other words, the relation we find obtaining between jays and other birds is the natural, normal condition of affairs, which has come about through a long period of adjustment.