Night is giving way to an overcast dawn as Alex Fish's rubber boots finally halt atop a root-snarled hump. We've been following his GPS receiver through dense tangles of a black-spruce bog for the past half hour. Now the search for spruce grouse (Falcipennis canadensis) begins.
It's late April, and we're at Red Lake Wildlife Management Area, a 320,000-acre tract of black spruce, jack pine, aspen, white cedar, and sedge meadows near the Canadian border in northwestern Minnesota. Male spruce grouse, awash in reproductive hormones, are putting on displays of fluttering, strutting, and swishing to attract females and intimidate competing males. This peak of courtship activity is the best time to find and study these otherwise quiet boreal birds.
Minnesota hunters harvest about 10,000 to 20,000 spruce grouse each year under a daily bag limit of five, according to DNR small-game harvest records. This compares with an average of 500,000 ruffed grouse taken annually. While many spruce grouse are likely harvested mistakenly by hunters pursuing ruffed grouse, some hunters enjoy hunting spruce grouse.
"Spruce grouse live in some of the wildest, most remote places in the state. And some hunters are attracted to the opportunity to pursue the bird in those areas," says Jay Johnson, DNR hunter recruitment and retention supervisor. "Other hunters pursue spruce grouse because it's a unique bird that can be harvested in only a handful of states."
Hunters have limited opportunities for prairie chickens and sharp-tailed grouse and longer seasons for ruffed grouse and spruce grouse. Northwestern Minnesota is one of the few areas where all four of the state's native grouse species can be harvested in a single season?a feat known in some hunting circles as a Minnesota Grand Slam.
For the past six weeks, Fish, a seasonal wildlife research technician with the Department of Natural Resources, has set out in the predawn darkness for a plot of forest to locate spruce grouse. When he reaches it, he makes a few field measurements, such as types of trees, density of underbrush, and height of understory vegetation.
Then he follows his GPS to another 16 stopping points within the 158-acre plot. At each one, he follows the same routine. First, he listens for a few seconds as the forest stirs. Then he takes weather readings. After noting various birds he's hearing, he opens a small plastic amplifier that adds one more sound to the cacophony of forest birds—the hen spruce grouse's call, known as a cantus.
A series of raspy warbles emanate from the speaker, and Fish's attention is immediately drawn to the sound of wing beats 50 yards behind us. After a few moments, we push through a tangle of underbrush to a tiny clearing where a male spruce grouse sits on a branch about 20 feet up in a black spruce tree. Seemingly oblivious to his early-morning visitors, the bird stretches his body to make the most of his 2-pound stature. Above his eyes, two brilliant red combs form elegant arcs. Beneath his chin, short feathers puff out like a beard. His chest and wings are a bold contrast of black and white; his orange-tipped tail feathers rise and fall slightly as if marking the seconds before a hen's approach.
Detecting a spruce grouse on the first stop is good, Fish says, because it could signal an uptick in spruce grouse breeding activity, and it means we'll see more birds. Fish's fieldwork is part of a survey on Red Lake WMA and the adjacent Beltrami Island State Forest. One goal of the study is to evaluate techniques for locating spruce grouse in future surveys. Additionally, researchers plan to learn more about whether specific habitats are especially attractive to spruce grouse during mating season. They'll look at the number of trees; the density of underbrush and of groundcover such as Labrador tea, leatherleaf, and sphagnum moss; and the number and size of open areas. This data will help wildlife managers understand how to improve habitat for this game bird, which was once more plentiful in northern Minnesota.
With enough data on grouse detections, researchers could one day create a computer model for identifying ideal habitats across the bird's range, says Mike Larson, DNR forest wildlife research group leader and a former grouse biologist. "We would be able to estimate the probability of a stand of trees being occupied by spruce grouse, based on the characteristics of the forest around the stand," he says. These timber stands would vary in size and contain suitable wintertime cover as well as areas for courtship and nesting.
Spruce grouse, which are at the southern edge of their range in Minnesota, face potential threats from changing forest management practices as well as impacts from projected climate change. For these reasons, in 2008 the Association of Fish and Wildlife Agencies recommended that states in spruce grouse range develop formal surveys for monitoring population change and conducting research on the effects of habitat alterations and hunting.
While there is no sign that spruce grouse populations are in trouble, biologists aren't certain of the bird's abundance or specific habitat needs in Minnesota. Citing this lack of population trend data, as well as the bird's dependence on the conifer-dominated landscapes of the boreal and near-boreal forest, the DNR in 2006 listed the spruce grouse as a Species of Greatest Conservation Need. The bird has been on the sensitive species list for Chippewa National Forest since 2004.
One of the reasons for the lack of spruce grouse population data is the secretive nature of the birds, Larson says. "Ruffed grouse drum, sharp-tails dance, and prairie chickens boom," he says of the state's other native grouse species. "But the spruce grouse puts on a much more subtle display, fluttering its wings as it flits from low tree limbs to the ground. Because it's less visible, it requires a much more intensive survey effort, and that's one reason we have much less data on the spruce grouse."
Before beginning the current study in 2011, Larson reviewed four historic studies of spruce grouse in Minnesota, done between 1951 and 1979. While each provided useful information, they were limited to unique study areas, making it difficult, Larson says, to apply the results to a broad geographic area.
While biologists focus on the spruce grouse as an indicator species, the bird is also a highlight species for birders across the United States, says DNR Nongame Wildlife Program supervisor Carrol Henderson. The spruce grouse is one of a handful of boreal birds that can be reliably spotted in northern Minnesota. "The boreal biome is very special," he says. "It's one of the few places in the United States outside Alaska where you can dependably see populations of spruce grouse, pine grosbeak, and great-gray owl, among a few others."
If you're fortunate enough to find a spruce grouse, you're likely to get a very good look at it. Perhaps the best-known feature of both sexes of spruce grouse is their seeming total lack of fear of humans. This unwariness has earned them the nickname "fool hen." Reports abound of hunters approaching the birds and knocking them dead with a stick. The female, slightly larger than a pigeon, somewhat compensates for her lack of caution with a brown, black, and gray camouflage pattern that allows her to blend into lichen-covered coniferous forests. The male, however, sports a loud contrast of black and white bars with brilliant red combs above each eye.
At the end of breeding season, hens create ground nests, often little more than a slight depression in a bed of conifer needles, under overhanging branches. A hen lays as many as 12 eggs, which hatch in 24 days. The chicks can fly in about two weeks, but they follow their mother until September or October.
Spruce grouse are found in coniferous forests in Canada and northern regions of the United States. In Minnesota, Larson says, the bird's range has varied through the years, generally coinciding with the presence of black spruce, jack pine, and white cedar. The adult spruce grouse's diet is made up almost entirely of short conifer needles.
Coniferous trees also provide a place for spruce grouse to escape predators such as hawks, owls, fisher, martens, and fox. While the birds show little fear of humans, the approach of a predator or even a dog causes the birds to flush wildly and dart high into the nearest tangle of trees. In winter the birds sometimes burrow into deep snow to avoid predators and to stay warm.
In the 1800s, spruce grouse were found as far south as Lake Mille Lacs. However, according to a 1951 Conservation Volunteer article by area game managers Milton Stenlund and Lester Magnus, spruce grouse were nearly extirpated from Minnesota after a period of intense logging and many forest fires from 1890 to 1915.
In the 1940s, regenerating forests had matured enough to support understories of balsam fir, spruce, and jack pine, thus prompting a resurgence of spruce grouse populations. More recently, spruce grouse have been most common in Lake of the Woods and Koochiching counties and the northern halves of St. Louis, Lake, and Cook counties. The range also includes eastern Roseau and northern Itasca counties and parts of Beltrami County.
Back at Red Lake WMA headquarters, DNR area wildlife manager Gretchen Mehmel is eager for more precise information to help improve habitat for spruce grouse populations. Mehmel was the first in the DNR to suggest looking into what more could be done for their habitat. She arranged funding for a large portion of the study from income derived from state management of federal land on Red Lake WMA.
In 2011, the first year of the project, crews detected 46 spruce grouse in about 978 systematically distributed points in 63 randomly selected plots centered on jack pine and lowland black spruce. They also found 40 spruce grouse at incidental sites, which weren't part of the survey route. In 2012 they detected 32 spruce grouse at 1,314 points in 83 randomly selected plots. Research will resume this spring under DNR grouse biologist Charlotte Roy, who will lead the design of a roadside survey to determine the distribution and population of the spruce grouse across its range in Minnesota.
For Mehmel and other wildlife managers in northern Minnesota, this study could help answer some important questions about managing forest habitat for spruce grouse in the future. "Like the moose, spruce grouse are kind of the canary in the coal mine for climate change," Mehmel says. "Because they're on the southern edge of their range in Minnesota, whatever we can learn now about spruce grouse habitat preference might be valuable for wildlife managers in the future who may need to protect those habitat types."
On Red Lake WMA, Fish and I have no difficulty locating spruce grouse on this warm, overcast day. Before noon, he's recorded seven detections—the most in a single day so far this 2012 season. On our way to our last stop, we sidestep numerous pitcher plants on the moss-covered forest floor. Fish notes a small patch of exposed soil that is likely the result of repeated landings of a male spruce grouse fluttering from the trees. As Fish bends to snap a few photos, a male spruce grouse darts through the underbrush on foot. Fish plays the cantus call to see if the bird will return.
Although the male does not return, a hen responds to the amplified song with her own cantus. Because both encounters occur away from a prescribed stop, Fish makes note of them as incidental detections. They are our last grouse encounters of the day, as our remaining hours in the black spruce bog pass uneventfully.
Back at the truck, with the sun still high in the sky, Fish tallies the day's spruce grouse detections at nine. As a bonus, he also notes golden- and ruby-crowned kinglets, boreal chickadee, black-capped chickadee, red-breasted nuthatch, winter wren, dark-eyed juncos, white-throated sparrows, hermit thrushes, and yellow-rumped warblers. "Not a bad day at the office," Fish says. Before the survey ends in the coming weeks, Fish will visit at least 13 more plots.
After a day of winding my way through dense tangles in Red Lake WMA, I see why so little is known about the spruce grouse. Gathering data on a bird that lives deep in the forest and is nearly silent and secretive for all but a few weeks each year is difficult, painstaking work. In time, however, this project and others like it will help unravel the mysteries of what this beautiful bird needs to sustain itself in Minnesota's boreal forests.