Gray Jay

From SongbirdReMixWiki

Jump to: navigation, search


Common Name: Gray Jay
Scientific Name: Perisoreus canadensis

Size: 11.5 inches (29 cm)

Habitat: North America; within the Northern United States and Canada. Found in found in the boreal forests across North America north to the tree-line and in subalpine forests of the Rocky Mountains south to New Mexico and Arizona.

Status: Least Concern. Global Population: 16,000,000 Mature individuals. 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.

Diet: Seed, fruits and some insects. Gray jays do not hammer food with their bill as do other jays, but wrench, twist, and tug food apart. Gray jays commonly prey on nestling birds

Breeding: Gray jays typically breed at 2 years of age. Pairs are monogamous and remain together for their lifetime, but a male or female will find another mate following the disappearance or death of their partner.

Gray jays cooperatively breed. Nesting 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 (Picea mariana), white spruce (Picea glauca), and balsam fir (Abies balsamea) 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 (Malacosoma dysstria) filled the interstitial spaces of the nest. Nests are usually built on the southwestern side of a tree for solar warming and are usually <1 nest diameter from the trunk. Nest height is typically 8 to 30 feet (2.4–9.1 m) above the ground.

Clutch size is 2 to 5 eggs. Incubation is performed only by the female and lasts an average of 18.5 days.

Cool Facts: Gray Jays readily capitalize on novel food sources, including food sources introduced by humans living on or passing through their territories. To the frustration of trappers using baits to catch fur-bearing animals or early travelers trying to protect their winter food supplies, and to the delight of modern campers, many individual Gray Jays quickly learn that humans can be an excellent source of food, even coming to the hand for bread, raisins, or cheese. Such familiarity has inspired a long list of colloquial names for the Gray Jay. In addition to the once official ‘Canada Jay,’ there are, lumberjack, meat-bird, camp robber, venison-hawk, moose-bird, gorby and, most notable of all, ‘whiskeyjack’. This a variant of an aboriginal name, variously written as wiskedjak, whiskachon, wisakadjak, and other forms, of a mischievous prankster prominent in Algonquian mythology.

The vast majority of Gray Jays live where there is a strong presence of one or more of black spruce (Picea mariana), white spruce (P. glauca), Englemann spruce (P. engelmanni), jack pine (Pinus banksiana), or lodgepole pine (P. contorta). 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 (Picea sitchensis). 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.

Gray jays warn each other of predators by whistling alarm notes, screaming, chattering, or imitating, and/or mobbing predators.

Found in Free Downloads

Personal tools