Perisoreus canadensisgray jay(Also: grey jay)

Geographic Range

Breeding range: The Gray Jay is found from tree line in northern Canada and Alaska south through boreal and subalpine forests to northern California on the west coast, Arizona and New Mexico in the Rocky Mountains, northern Wisconsin in the midwest, and New York in the east.

Winter range: The non-breeding range is essentially the same as the breeding range, as the Gray Jay does not migrate except for (in late fall and winter) occasional altitudinal movements in the Rockies and rare latitudinal movements elsewhere, probably due to food shortages.

Perisoreus canadensis has never been recorded outside of North America.

(Sibley 2000, Strickland 1993, Ehrlich 1988)

Habitat

Gray Jays are associated with coniferous and coniferous-deciduous forests of the boreal and sub-alpine vegetative regions. They are most commonly found in spruce and fir woods (with occasional aspens or birch). Despite its association with humans, this jay does not live in towns or developments. It is exclusively a bird of remote forests. In fact, Gray Jays disappear as soon as a camp becomes a permanent settlement.

(Strickland 1993, Madge 1994, Goodwin 1986)

Physical Description

Often described as resembling an oversized chickadee, P. canadensis is a fluffy, pale-gray, long-tailed, short-billed, crestless jay. Gray Jays, while sexually monomorphic, do show strong regional variation, with three distinguishable populations: Pacific, Rocky Mountain, and Taiga. All adult variations have black eyes, bills, legs, and feet and white auriculars (ear patches) and throats. Pacific birds show extensive dark on the head and brownish-tinged backs. Rocky Mountain birds south of Canada have a whiter head. Taiga birds resemble Pacific birds, but are grayer above and have a grayer (rather than whitish) belly. Juveniles from all populations are sooty overall and gray-billed with white malar stripes.

Perisoreus canadensis is 11.5 inches (29 cm) long and has a wingspan of 18 inches (45 cm). Normal adult weight is 2.5 ounces (70 grams).

Gray Jays have a clear, pleasant whistle of wheeeooo or wheee-ah. Calls also include a low, husky chuf-chuf-weef and a very rough, dry kreh kreh kreh kreh alarm call. Like Blue Jays, P. canadensis sometimes sound a screeching jaaay. Gray Jays are known to mimic sounds.

(Sibley 2000, Peterson 1990)

  • Average mass
    70.3 g
    2.48 oz
    AnAge

Reproduction

Perisoreus canadensis breeds in coniferous forests and sometimes in mixed coniferous-deciduous woodlands. The male chooses a nest site usually in a conifer (spruce or fir), at a height of 5 to 12 feet (1.5 - 3.6 m), sometimes as high as 30 feet (9.1 m). The male initiates building the nest - a thick cup of twigs, bark strips, grass, moss, lichen, and spider webs. The inside is lined with fine grasses, moss, hair, feathers, and fur. The female joins the building over a period of up to 3 weeks or more.

The breeding season begins in March, while snow is still on the ground and temperatures are well below freezing, and ends by mid-May. Curiously, second broods are not attempted in ostensibly favorable later months. Three to four eggs (29 X 21 mm) are laid (range 2-5) and incubated by the female alone. The eggs are pale greenish or gray-green and heavily speckled, spotted, or blotched with olive and paler gray. After a 16 to 18 day incubation period, the nestlings hatch slightly downy and altricial. The young are fed by both parents and fledge at 22 to 24 days.

Cowbird parasitism has not been observed.

(Baicich 1997, Veghte 1964)

  • Average eggs per season
    3
    AnAge
  • Average time to hatching
    17 days
    AnAge

Lifespan/Longevity

Behavior

The Gray Jay is well-known for its bold, almost tame, behavior around humans. In logging camps, at mountain resorts, and at backwoods cabins, the "Camp Robber" or "Whiskey Jack" will brazenly raid campsites or cabins, even taking food from human hands.

Juvenile Gray Jays are divided into "stayers" and "leavers:" the dominant brood member expels siblings from the natal territory. At 55 to 65 days old, fledglings fight among themselves for the privilege of staying with the parents outside of the breeding season. The stayers have a better chance of surviving the first summer than leavers, but they do not have a chance to inherit the natal territory. The advantage probably lies in the increased food still stored in the parents' territory.

(Terres 1995, Strickland 1991)

Communication and Perception

Food Habits

Gray Jays are omnivorous, commonly eating arthropods, berries, carrion, eggs, nestling birds, and fungi. Gray Jays use a variety of foraging techniques including flycatching, foliage gleaning, ground gleaning, and even aerial pursuit of rodents. Nestlings are fed partially digested food.

One of the most interesting traits of the Gray Jay is its food storage ability. This Jay has unusually large salivary glands that produce copious sticky saliva. They use this saliva to impregnate and encase food, creating a bolus that will adhere to trees. Away from ground scavengers and protected from the wind and snow, these caches allow efficient food hoarding. Gray Jays have been observed making over 1,000 caches in a single 17-hour day. This behavior may be the major adaptation enabling Perisoreus canadensis to occupy the hostile boreal regions during the winter. Fittingly, the genus Perisoreus means "hoarder."

(Dow 1965, Ehrlich 1988, Strickland 1993, Terres 1995)

Economic Importance for Humans: Positive

Perisoreus canadensis is valuable as an indicator of the health of boreal and sub-alpine systems. Although these areas are less altered than most biomes, acid precipitation and global climate change could have a noticeable effect on this species. Because they are specially adapted to harsh winter environments, Gray Jays may be negatively impacted by warming trends. Thus, the species could serve as an early-warning system for cascading effects of anthropogenic climate change.

Economic Importance for Humans: Negative

While many corvids can cause extensive crop damage, the Gray Jay, because of its habitat requirements, does not overlap with farms. It can, however, be an annoyance (some would say a great delight) to campers, as it will linger in campsites and attempt to pilfer food.

Conservation Status

Perisoreus canadensis is locally common over its wide range, but there is little precise population data. The Breeding Bird Surveys (BBS) from 1966 to 1993 show a -0.6% decline over that period, but with a statistically insignificant sample. The short-term BBS data trend from 1984 to 1993 show a 51.8% increase during that time (P<.01). Gray Jays are very vulnerable to human-set terrestrial fur-bearer traps.

The Gray Jay is not listed as Endangered or Threatened in the United States or Canada. No special management measures have been implemented for the species.

(Madge 1994, Price 1995)

Contributors

Matthew Dietz (author), University of Michigan-Ann Arbor, Terry Root (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

References

Baicich, P., C. Harrison. 1997. A guide to the nests, eggs, and nestlings of North American birds. San Diego,CA: Academic Press.

Dow, D. 1965. The role of saliva in food storage by the Gray Jay. Auk, 82: 139-154.

Ehrlich, P., D. Dobkin, D. Wheye. 1988. The birder's handbook: a field guide to the natural history of North American birds. New York: Simon & Schuster, Inc..

Goodwin, D. 1986. Crows of the world. Suffolk, England: St. Edmundsbury Press Ltd..

Madge, S., H. Burn. 1994. Crows and jays: a guide to the crows, jays, and magpies of the world. New York: Houghton-Mifflin Co..

Peterson, R. 1990. A field guide to western birds. New York: Houghton-Mifflin Co..

Price, J., S. Droege, A. Price. 1995. The summer atlas of North American birds. San Diego, CA: Academic Press.

Sibley, D. 2000. National Audubon Society Sibley guide to birds. New York: Alfred A. Knopf, Inc..

Strickland, D. 1991. Juvenile dispersal in Gray Jays: dominant brood member expels siblings from natal territory. Canadian Journal of Zoology, 69: 2935-2945.

Strickland, D., H. Ouellet. 1993. Gray Jay (Perisoreus canadensis). A Poole, F Gill, eds. The birds of North America. Philadelphia, PA: The Birds of North America, Inc..

Terres, J. 1995. The Audubon Society encyclopedia of North American birds. New York: Random House Publishing, Inc..

Veghte, J. 1964. Thermal and metabolic responses of the Gray Jay to cold stress. Physiological Zoology, 37: 316-328.