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This western race of our familiar “whisky jack” is described by Ridgway (1904) as similar to our eastern bird, but it is larger and lighter colored; the whole head is white, except immediately around and behind the eyes, which, together with the hind neck, are slate-gray; the upper and under parts are paler gray. Young birds, in juvenal plumage, are paler than the young of canadensis or fumifrons, the pileum being much paler gray or grayish white and the feathers of the under parts more or less tipped with white or pale grayish. Ridgway gave it the appropriate name of “white-headed jay,” and, on account of this prominent character, it is locally called “baldhead,” “tallowhead,” or “whitehead”; it is also commonly known as the “camp robber,” and many of the popular names applied to our eastern bird are also used to designate it. The name “jay” is usually used by the westerner for one of the races of the Steller’s jay.
The Rocky Mountain jay is appropriately named, for it is confined mainly to the boreal zones in the Rocky Mountain region from southern Canada to Arizona and New Mexico. Its breeding range seems to be limited to the heavily forested regions in the mountains, from the lower limit of coniferous forests up to timberline, the altitude varying with the latitude. Referring to its haunts in the Yellowstone National Park, Wyo., M. P. Skinner (1921) says: “While I have frequently found Rocky Mountain Jays in the smaller meadows and openings, still it is apparent they like the forests best. Forests of lodgepole pine, limber pine, fir, spruce, cedar, and even aspen groves and willow thickets constitute their chosen haunts. Their nests are in the lodgepole pine belt between the 7500 and 8000 foot levels.”
Aretas A. Saunders writes to me: “This bird is a common species all through the mountainous parts of Montana. Though a resident, and present throughout the year, it is much more in evidence from early in August to late in February than from March to July. From about August 5 on, these birds are likely to be encountered daily until late in February. But through the spring and early summer a sight of one of these birds is a rare thing. I find that I have records of their occurrence in every month of the year, but the records are very few, as compared to late summer and fall.”
Fred Mallery Packard writes to me of the status of this jay in Estes Park, Colo.: “One of the commonest birds of the Canadian and Hudsonian forests in summer; usually found between 8,500 feet and timberline at 11,000 feet, but occasionally as high as 13,000 feet. In winter most of these jays descend to the lower edge of the Canadian and Upper Transition Zones (8,000 to 9,000 feet), some to Estes Park village at 7,500 feet, while a few winter as high as timberline.”
Referring to Colorado, Dr. Coues (1874) quotes Mr. Trippe as saying: “I have never seen the Canada Jay below 9,000 feet, even in midwinter; and but rarely below 9,500 or 10,000. During the warmer months it keeps within a few hundred feet of timber-line, frequenting the darkest forests of spruce, and occasionally flying a little way above the trees.”
In New Mexico its range seems to be mostly above 11,000 feet, where Mrs. Bailey (1928) says that “it belongs among the hemlocks and spruces of the Hudsonian Zone.” She gives a number of records for north-central New Mexico, ranging from 7,800 up to 12,000 feet, but says that 9,500 feet is about the usual lower limit of its range in fall and winter.
Nesting.—W. C. Bradbury (1918), after several unsuccessful attempts and much heavy traveling in deep snow, finally succeeded in 1918 in securing three nests of the Rocky Mountain jay in Colorado. One nest was taken in Grand County on May 2 at an altitude of 8,600 feet; the nest, which contained only two heavily incubated eggs, was in a lodgepole pine “about twenty-five feet from the ground, in a rather bushy top, located close to the trunk on a small limb. Some of the strings used in the nest were neatly bound around the limb upon which it rested. The outside framework is “composed chiefly of pine and other twigs.” The “nest proper” is “composed of fine grasses, cotton strings of several sizes, and large amounts of unravelled rags and white rabbit hairs; lined with same material and feathers. There are several pieces of cotton cloth spread between the twig foundation and the nest proper.”
Another nest was at “about 8,700 feet altitude in Saguache County, Colo., in open stand of lodge-pole pine. The nest was on the south side of a tree fifteen feet high, located on two limbs two and one-half feet from the trunk and five feet from the ground. * * * Nest proper composed of fine grasses and bark fiber neatly and closely woven together, and warmly lined with chicken and occasional grouse and jay feathers.” This nest contained three slightly incubated eggs on April 26.
The third nest was taken in Gunnison County, at an elevation of 10,600 feet, on April 21, containing two eggs with well-developed embryos. “The nest was in the top of a white spruce, fifty-five feet above the surface of the snow, which was fourteen feet deep on the level. * * * The entire structure is composed of spruce twigs and tree moss, with a small amount of coarse wood fiber and an occasional feather, all very closely and firmly intermixed and woven together. The cup is lined with tree moss, grouse and a few other feathers.”
These nests are evidently quite similar to those of the Canada jay, and the size is about the same, though the inner cup seems to be shallower, 1¾ inches. The over-all outside diameter varies from 6½ by 7 to 7 by 9 inches; the outside height is 3 to 4 inches; and the inner diameter of the cup varies from 3 to 3½ inches.
Mr. Skinner (1921) says that in Yellowstone National Park “nests are built in tall lodgepole pines during early April at from 7500 to 8000 feet elevation. They are about thirty feet up, or two-thirds of the distance from ground to tree top, and made of straw placed in the angles between the trunk and a limb about two inches in diameter. The inner nest is mostly of pine needles.”
Alfred M. Bailey tells me that he and R. J. Niedrach found two nests in the mountains of Colorado; one was 20 feet from the ground in a small Douglas fir, at 9,000 feet; and the other was 25 feet above ground in an Engelmann spruce, at an elevation of 11,000 feet (pl. 4).
Eggs.—The Rocky Mountain jay seems to lay usually two or three eggs, perhaps sometimes four. These are practically indistinguishable from those of the Canada jay, though some are more heavily marked. The measurements of 20 eggs average 29.9 by 21.7 millimeters; the eggs showing the four extremes measure 33.0 by 24.0, 32.0 by 24.5, and 26.6 by 20.0 millimeters.
Food.—This “camp robber” has practically the same feeding habits as others of the species, frequenting the camps to steal, eat, or carry off almost anything edible. It often does considerable damage to food left in camp or to baited traps. Wilbur C. Knight (1902) writes: “Some years ago while deer hunting we had several carcasses hanging in the trees near by and some quarters that had been skinned. I noticed the birds flying away from the meat whenever I came into camp and upon examining the quarters that were skinned, I found that they had made several holes through the dried surface, large enough to admit their heads, and that they had eaten from each opening from one to two pounds of meat and had entirely destroyed the quarters.”
Mr. Skinner (1921) says: “Truly omnivorous eaters, the Rocky Mountain Jays pick up oats dropped about stables or along the roads; catch caterpillars, black worms, and grasshoppers; and once I saw a Jay try for a locust, although he missed and did not try again that I could see.” Mrs. Bailey (1928) adds “wild fruits, including elderberry, bearberry, sumac, and viburnum; also scattered grain in corrals; insects, especially grasshoppers and caterpillars; small mammals, meat, and camp food.” On the Upper Pecos River she (1904) saw them eating toadstool.
Mr. Munro has sent me some notes on the stomach contents of Rocky Mountain jays taken in British Columbia. In four stomachs collected on September 20, 1939, one contained seeds of Rosaceae to the extent of 70 percent; two others contained 70 percent insects, including a large dipterous pupa, parts of two large Diptera, and other insect remains; fragments of a beetle and seeds of the serviceberry were found in some of the stomachs. In the three stomachs taken December 3, 1926, seeds of Rosaceae figured largely, from 95 to 98 percent; mixed with them were a few seeds of serviceberry and a few insect fragments. Mr. Packard writes to me:
“Every camp and cabin in the higher parts of the park has its coterie of jays that depends to some extent upon food discarded by campers to supplement their own forage. A site may be used but once or twice a year, yet within 5 minutes of a person’s arrival there the camp robbers are hopping on nearby trees in anticipation of a handout.
“On July 5, 1939, shrill cries coming from the top of a small Engelmann spruce near timberline at Milner Pass disclosed two ruby-crowned kinglets darting at a pair of camp robbers, each of which had a nearly grown kinglet in its claws. The jays paid little attention to the agitated parents, but calmly devoured the nestlings while we watched. In each case, the jay opened the stomach of its prey, ate the viscera, and then pecked at the head. I have also observed camp robbers carrying nestling Audubon’s warblers in midsummer.”
Behavior.—In general habits and behavior the Rocky Mountain jay is much like its better-known northern relative; it has the same thieving habits, is equally bold and inquisitive, and is quite as sociable and friendly, the camper’s companion and a nuisance to the trapper or the hunter. Mr. Skinner (1921) calls attention to two points, not mentioned under the preceding race; he says:
The flight of a Rocky Mountain Jay seems weak. A few wing strokes carries the bird along slowly and upward slightly, then a sail carries him down at about the same angle, and this sequence is repeated over and over again, resulting in a slow flight of long, shallow undulations. * * * Birds of the air and of the tree tops as they are, when they are on the ground they move somewhat awkwardly in a series of long hops, a little sideways perhaps, a good deal like crows and ravens.
Its migrations, if they may be called such, are more altitudinal than latitudinal. It wanders to lower elevations in winter and often seeks the vicinity of permanent camps and settlements in search of food, retiring to the higher altitudes at the approach of the breeding season. During the nesting season it is very retiring and secretive but is much more in evidence during fall and early in winter.
Mr. Saunders writes to me: “They stay around lumber camps or other places, feeding on garbage, particularly scraps of meat or fat, but also bread. At such seasons, if one stops to eat lunch anywhere in the evergreen forests, the birds will appear shortly, and are very tame, and ready to share all the lunch one is willing to give them.”
Mr. Munro says in his notes: “In the heavy still forest on a snowy day, they came fluttering silently from the heavy timber in response to an imitation of the pigmy owl call—soft, fluffy birds like overgrown chickadees.”
Voice.—Mr. Saunders (MS.) says that this bird is an exceedingly quiet one, in contrast to other jays; only once or twice has he heard one make a sound.
Mr. Munro writes in his notes sent to me: “These birds were heard imitating the call of pine grosbeaks, which were nesting in the vicinity. They also imitated the calls of pigmy owl and red-tailed hawk. I was impressed by the exact imitation of the pigmy owl made by two pairs which were called up at different places by an imitation of the owl call. I was sure that a pigmy owl was answering me until the jays appeared. Both the single hook note and the quavering tremolo were given. In one instance, both were given after I had whistled only the single note.”
