Gray jays are winter residents in lodgepole, spruce

By Jeff Mitton

I sat at midday in the sun, in a lodgepole pine forest being thinned by bark beetles.

I was taking a break for lunch and enjoying the view when I realized that not only was I not alone, but somebody was watching me. On a branch 10 feet over my head a handsome bird stared intently at me, or more precisely, at my lunch.

A gray jay swooped to the ground and hopped closer, eager to share.

Gray jays, Perisoreus canadensis,are also called whiskey jack, a corruption of Wisakedjak, an Algonquin name for a mischievous and disobedient mythical creature. It appears that gray jays have been pestering humans for centuries if not millennia.

Gray jays are a member of the family Corvidae, which includes ravens, crows, jays, magpies and nutcrackers. Their closest relatives, in the genusPerisoreus,are the Siberian jay in northern Europe and eastern Russia and the Sichuan jay in Tibet and northwestern Sichuan.

Gray jays have never been seen outside of North America, but within North America they are widespread, ranging from isolated populations in New Mexico and Arizona to Alaska and across the forests of Canada to Newfoundland. The vast majority of gray jays are found in forests of lodgepole pine, Engelmann spruce, black spruce and white spruce.

Like many other members of this family, gray jays commonly feed on the nestlings of other species, but they also take chorus frogs, salamanders, toads, mice, a wide variety of insects, mushrooms, seeds and berries.

Gray jays are year-round residents of high-elevation and high-latitude conifer forests, and their life history and behavior distinguish them from the majority of other birds and suit them to habitats with extreme cold and short growing seasons.

Gray jays mate for life and maintain a permanent territory for feeding and nesting. Effectively, they are very sedentary birds and their lack of migrations and mixing allows populations to become adapted to specific local environments. The morphological and behavioral differentiation associated with site-specific adaptation inspires ornithologists to recognize 13 subspecies.

Reproduction is surprisingly early in the season. Two to five eggs are laid in February or March, in the depth of winter when there are no insects, nuts, berries or amphibians to eat.

Much of the previous year was spent harvesting food, working a beakful of food into a paste made sticky with saliva and furtively cached in areas in the territory. A packet of food may be stuck under a flake of bark, or on a branch hidden by needles. These packets of food sustain the parents and fortify growing nestlings before most bird species have returned from their winter ranges in the tropics and subtropics.

After the nestlings fledge they become competitive and combative and ultimately the strongest drives the others out of their home territory. The victorious youngster spends the next year in the territory, receiving food and valuable training from its parents. In return, it helps feed its younger sibs that will hatch the following spring.

Although the stay-at-home youngster assumes the additional responsibility of feeding younger sibs, the mortality rate for stay-at-homes is 52 percent, in comparison to a whopping 85 percent for those forced to leave their natal territory. Gray jays have a lot to learn about getting along in a frigid conifer forest, particularly about caching food to survive along winter.

Apparently, adults have much valuable wisdom to impart to their offspring.

Jeff Mitton (mitton@colorado.edu) is a professor in the Department of Ecology and Evolutionary Biology at the University of Colorado. This column originally appeared in the Boulder Camera.

December 2010