AppearanceIt is one of three members of the genus ''Perisoreus'', the others being the Siberian Jay, ''P. infaustus'', found from Norway to eastern Russia and the Sichuan Jay, ''P. internigrans'', restricted to the mountains of eastern Tibet and northwestern Sichuan. All three species store food and live year-round on permanent territories in coniferous forests.
DistributionThe gray jay is a native resident from northern Alaska east to Newfoundland and Labrador and south to northern California, Idaho, Utah, east-central Arizona, north-central New Mexico, central Colorado, and southwestern South Dakota. It is also a native resident in northern Minnesota, northern Wisconsin, northern Michigan, northern New York, and northern New England.
StatusGray Jays are widespread in boreal and subalpine habitats only lightly occupied by humans. Significant human impacts may nevertheless occur through anthropogenic climate warming. Gray Jays at the northern edges of their range may benefit from the extension of spruce stands out onto formerly treeless tundra. A published study has documented a decline at the southern edge of the Gray Jay’s range, however, and plausibly linked a local decline in productivity to warmer temperatures in preceding autumns. Such warm temperatures may encourage spoilage of the perishable food items stored by Gray Jays upon which success of late winter nesting partly depends.
BehaviorGray jays do not hammer food with their bill as do other jays, but wrench, twist, and tug food apart. Gray jays commonly carry large food items to nearby trees to eat or process for storage, possibly as defense against large scavengers. They are "scatterhoarders", caching food items among scattered sites for later consumption.
Any food intended for storage is manipulated in the mouth and formed into a bolus that is coated with sticky saliva, adhering to anything it touches. The bolus is stored in bark crevices, under tufts of lichen, or among conifer needles.
Risk and energy expenditure are factors in food selection for gray jays. Gray jays select food on the basis of profitability to maximize caloric intake. Increased handling, searching, or recognition times for a preferred food item lowers its profitability.
The gray jay takes advantage of man-made sources of food, hence the names "camp robber" and "whiskey Jack". According to Maccarone and Montevecchi, human observers do not inhibit gray jay's feeding behavior; however, Rutter claims that "once having identified man with food it does not forget". He found that after a nesting female was accustomed to being fed by humans she could be enticed to leave the nest during incubation and brooding.
HabitatThe vast majority of Gray Jays live where there is a strong presence of one or more of black spruce, white spruce, Englemann spruce, jack pine, or lodgepole pine. Gray Jays do not inhabit the snowy, coniferous, and therefore seemingly appropriate Sierra Nevada of California where no spruce and neither of the two named pines occur. Nor do Gray Jays live in lower elevations of coastal Alaska or British Columbia dominated by Sitka spruce.
The key habitat requirements may be sufficiently cold temperatures to ensure successful storage of perishable food and tree bark with sufficiently pliable scales arranged in a shingle-like configuration that allows Gray Jays to wedge food items easily up into dry, concealed storage locations. Storage may also be assisted by the antibacterial properties of the bark and foliage of boreal tree species. An exception to this general picture may be the well-marked subspecies ''P. c. obscurus'', once given separate specific status as the “Oregon Jay”. It lives right down to the coast from Washington to northern California in the absence of cold temperatures or the putatively necessary tree species.
ReproductionNesting typically occurs in March and April. Male gray jays choose a nest site in a mature coniferous tree and take the lead in construction. Gray jay nests were found in black spruce, white spruce, and balsam fir trees in Ontario and Quebec, with black spruce predominating. Cup-shaped nests were constructed with brittle dead twigs pulled off of trees, as well as bark strips and lichens. Cocoons of the forest tent caterpillar filled the interstitial spaces of the nest.
PredatorsGray jays are consumed by several bird species including great gray owls, northern hawk-owls, and Mexican spotted owls. Gray jay remains were found in the nest sites of fisher and American marten. Red squirrel eat gray jay eggs.
Gray jays warn each other of predators by whistling alarm notes, screaming, chattering, or imitating, and/or mobbing predators.
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