DULUTH, Minn.-The Minnesota Department of Natural Resources is looking for volunteers to trek across the north woods later this winter and count grouse poop in the snow, spruce grouse poop in particular.

The spruce grouse may be the Rodney Dangerfield of the northern forest - it doesn't get much respect - often referred to as "fool's hen" because they tend not to fly away when approached.

They aren't particularly sought-after by hunters; some say their meat tastes like pine needles. They aren't rare enough to get most birders excited and they live in very dense, evergreen forests where most people don't wander.

Thus we don't know a whole lot about spruce grouse. In fact, while the bird exists across much of Canada and the far northern tier of U.S. states, until now no one has developed an accurate method to figure out their population trends.

"This is really the first effort to accurately track population dynamics for the eastern subspecies of spruce grouse," said Grand Rapids-based DNR grouse researcher Charlotte Roy.

Spruce grouse don't really drum, like male ruffed grouse in spring, so there's been no way to check if their numbers are going up or down, or even where in Minnesota they live, simply by listening in the woods.

"Spruce grouse females do a cantus call (to attract males) in the spring. But not all of them do it and it's only for a short period. We found it's not very reliable," said Roy. "But you can tell the difference between a spruce grouse fecal pellet and a ruffed grouse pellet pretty easily, so we're going to count pellets."

Easy, important work for volunteers

For the record, spruce grouse fecal pellets are usually greenish-black due to their diet of spruce, balsam fir and pine needles. The pellets are also long and slender. Ruffed grouse pellets are yellowish-brown, shorter and fatter.

The best time to look is in late winter and early spring, as the snow starts to melt. The winter's accumulation of pellets is exposed, usually intact.

"The pellets are surprisingly visible. There can be a lot of them if you look in the right places," Roy said. "And (volunteers) don't need to be out there on any exact date or condition. Just before the snow melts."

To make sure volunteers look in the right places, training sessions will be held in February or March. Volunteers need only commit to one day each spring to survey two tracts, but they are asked to keep up the commitment for three years to reduce retraining.

A GPS unit with attached camera will be provided for the survey day.

Already moving north?

DNR and other researchers have been looking for spruce grouse pellets for four years, along with help from tribal natural resources staff and wildlife biologists from the Superior and Chippewa national forests. So far they have found them almost exclusively north of U.S. Highway 2, ranging as far west as Red Lake and up to Grand Portage Reservation to the east.

"We've narrowed it down a little. We found they aren't distributed as far south as we may have thought earlier," Roy said, noting that may be a problematic trend.

Jeremy Cable, a biologist for the Chippewa National Forest, which is participating in the spruce grouse effort, said the bird is only rarely reported in that area. Four routes will be searched for fecal pellets within the 650,000 acres of federal land within the Chippewa boundaries now at the southwest corner of spruce grouse range in Minnesota.

"We're not sure just how many we have," Cable said. "We think we're on the edge of their range now. We suspect we had more of them in the past."

That's partially because the national forest, over the past 150 years of logging, has trended toward fewer evergreens and more aspen trees. The Forest Service has been working over the past 15 years to reverse that trend and restore more conifers, which would attract spruce grouse, Cable said. He noted the grouse is considered a "sensitive species" by the federal agency, not endangered but sensitive to land uses such as logging.

"It's part of what bases our decision for land management, how certain species are impacted," Cable said.

The DNR gets a little information on spruce grouse from its annual survey of small game hunters. An estimated 10,000-20,000 are shot each autumn. But it turned out the numbers of spruce grouse reported shot was tied more to the population of ruffed grouse, which lead to shifts in ruffed grouse hunter activity, than to the actual spruce grouse population.

"As a biologist, trying to set sustainable harvest levels, we really lack even basic population information on this species," Roy said.

In addition to getting the first accurate population trend analysis and population range, researchers hope to get a sense of the most important habitats for the bird.

Roy says the spruce grouse may be joining more iconic northern species such as moose and lynx - species already being affected by climate change, shifting habitats and the trend to warmer weather.

Because spruce grouse have adapted to spruce forests, and because those forests are dependent on very cold winters - like this one, with temperatures colder than 40 below zero - to keep their advantage over other tree species, it's not clear how spruce grouse will adapt if the coldest winters are less frequent and spruce trees diminish.

In 2015 researchers at the University of Minnesota published a report in the journal Nature Climate Change that used growing plots near Cloquet and Ely and added the amount of warmth expected later this century. Spruce and fir, which thrive in cooler areas, suffered up to a 40 percent decline in growth when warmed just a few degree.

Another study published in the journal Global Change Biology in 2017 found spruce and fir among the most vulnerable tree species to long-term warming.

"I do think spruce grouse are in danger of being pushed out of Minnesota by climate change's impact on habitat. Not tomorrow, but over time," Roy said. "They depend on the species like black spruce and jackpine that really needs super-cold winters to keep their advantage over other tree species."

About spruce grouse

• Falcipennis canadensis

• Size: 16 to 19 inches long, just over one pound - similar in size and shape to the ruffed grouse.

• Coloration: Black and brown banded with white. Darker than ruffed grouse; head is a colorful mix of red, yellow and white, especially during the spring mating season.

• Sounds: Both sexes make a soft clucking sound. Females make a territorial cantus call in spring that attracts males to display.

• Nesting: Spruce grouse mate in April or May. Hens lay up to 12 eggs on the ground that hatch in 24 days. Chicks can fly in two weeks but stay with their mother for about three months.

• Food: Spruce needles and buds. Young birds eat mainly insects in summer.

• Winter survival: Prefers to roost nightly in deep snow but will settle for thick conifers.

• Predators: Great horned owls, goshawks, martens, fisher and foxes. Some hunters pursue them but most are taken incidentally by ruffed grouse hunters.

• Nickname: Spruce hen, fool's hen, fool's grouse because they often are not wary of people. But researchers say that's not because they are stupid; they just live in dense evergreen forests and don't get attacked by predators very often.

Source: Minnesota DNR

Volunteer grouse poop counters needed

• Commit to a half-day of training during the late winter to learn spruce grouse and ruffed grouse pellet identification and specific GPS skills .

• Commit to surveying at least two routes on one day each year for three years.

• Surveys require the ability to use a GPS unit and walk a circular transect of 100 meter radius around a road-based point as the snow is melting.

• Record the number of spruce grouse roost piles and individual fecal pellets encountered within 1 meter of the transect, along with information on most recent snowfall and the primary conifer trees in the area. You must be able to tell the difference between jack pine, tamarack, balsam fir, red pine, white cedar and black spruce trees.

• Ability to walk through possibly deep snow in dense forest cover

To sign up or for more information, contact Charlotte Roy, DNR grouse research scientist, at Charlotte.roy@state.mn.us or call (218) 328-8876.