September 22, 2006

Cheyenne, Wyoming - Autumn’s chill and snow sends elk and deer to lower elevations and waterfowl to warmer climates. But the blue grouse, one of Wyoming’s popular game birds, does the opposite, heading from its summer range of 6,000 to 8,500 feet to higher elevations up to 11,000 feet.

This blue grouse phenomenon is termed "reverse migration," but it’s not the only trait that makes this mountain grouse a unique and intriguing bird.

"The blue grouse’s migration is unique among game species," said Harry Harju, retired head biologist and assistant Wildlife Division chief for the Wyoming Game and Fish Department. "Heading to higher elevations for the winter eliminates the habitat competition animals encounter at lower elevations."

Harju earned his doctorate researching blue grouse ecology at the University of Wyoming.

Hens with broods begin the uphill trek in August, although adult males have been on the winter range since July. Sept. 1, when the blue grouse hunting season opens, the birds are scattered through both their summer and winter range. By October most birds have reached their winter grounds. With the advent of spring, nature pushes the bird’s down button to pursue the ritual of courtship and nesting.

Roosters start establishing courtship territories upon arrival around the first week of April. Hens begin arriving 2-3 weeks later. The entire population has reached the breeding area by May.

Blue grouse courtship grounds are less visible than those famous flatland romantics: the sage and sharp-tailed grouse. Close to timber along the forest’s edge, solitary dominant males perform an equally intriguing display of avian antics. They jettison straight up, 1-2 feet, with an exaggerated wing beat and land after making an incomplete midair turn. While on the ground, or on a tree limb, they utter a muted hoot and puff out red air sacs, rimmed with white feathers on their neck. The males tirelessly perform the ritual trying to gain favor of the hens nearby.

"Blue grouse males perform the display alone," Harju says. "But there may be several grouse territories very close to each other, and there are probably younger males nearby in the timber who were unsuccessful in establishing their own territories."

Hens make a shallow depression under a small tree or bush to nest. They border the depression with any available material (including leaves, needles and grass), lay 5-9 pinkish-buff eggs and incubate 26 days. If her nest is destroyed, the hen likely will try again. Males share no responsibility incubating or raising the brood.

Around 10 days old, chicks first take wing and by three weeks can fly fairly well. Blue grouse chicks are precocial, meaning they’re responsible for finding their own food upon hatching. Needing protein for quick development, chicks eat mostly insects the first six weeks. Adults eat some insects, too, but the majority of their summertime fare is forb seed heads, leaf ends, various berries, juniper needles, chickweed and dandelion. In another unique trait, the species dine exclusively on pine and fir needles in the winter - and specifically just the outer two thirds of the needle. Wyoming birds seem to prefer to winter on windswept ridges or the edges of patches of either lodgepole, limber or whitebark pine and Douglas or sub-alpine fir. Broods may stay with hens through the winter.

"Blue grouse seem to thrive on winter," Harju said. "They arrive on their breeding grounds at their heaviest weight of the year."

But how the bird maintains its very white muscle and superb, mild taste on that diet, instead of smelling like creosote, is a mystery.

Wyoming supports two distinct subspecies. The "dusky" grouse inhabits the Snowy Range, Sierra Madres and other smaller ranges in southeast Wyoming. The state’s northwest forests are home to the "Richardson’s" grouse. The Richardson subspecies is browner and lacks the broad gray tail band of the dusky.

Because the population is scattered the first month of hunting season, success is often spotty. Harju offers this tip: "Hunters should log the location, elevation and date where they find birds, then return to those spots about the same dates in following years. The blue’s migration clock is very predictable."

Many blue grouse are bagged incidentally to deer and elk hunting trips. Blue grouse are a very under harvested resource and that’s why Wyoming has no weapon restrictions for taking them and very long seasons.

"It’s a game bird that’s often overlooked. The hunting isn’t crowded, and they are excellent table fare," Harju said. "While the birds aren't considered much of a challenge to kill because they often take refuge in trees and sometimes seem reluctant to fly, once they've been hunted, they become quite wild and flush more quickly. If you don't see them fly into a tree, they can be very difficult to find, since their coloration blends in very well with the background, and they are very difficult to flush out of a tree since they often land a long way from the ground. When they do flush, they often dive off the mountainside, making for very difficult wing shooting."

During the 2005 Wyoming season, 4,986 blue grouse hunters were afield 19,782 days and bagged 13,076 blue grouse.

The blue grouse season runs through Nov. 30. "Late October or November hunting can be very difficult," Harju said. "After there’s snow on the ground, birds generally stay in the trees - except on very nice sunny days - and are difficult to see and flush."