REGIONAL— Researchers in northern Minnesota are hoping that a new method of estimating the region’s spruce grouse population will give wildlife managers a better handle on the species’ …
REGIONAL— Researchers in northern Minnesota are hoping that a new method of estimating the region’s spruce grouse population will give wildlife managers a better handle on the species’ abundance and population trends. That could prove important in maintaining the species in the state in the face of climate change.
Using dozens of agency cooperators and citizen volunteers, the new survey used spruce grouse droppings as a means of documenting the presence of spruce grouse at dozens of locations across the northern third of Minnesota. By conducting the survey annually, researchers can detect meaningful changes in the population.
For years, researchers have considered the spruce grouse to be notoriously difficult to count and the abundance of the species has typically been assessed based on hunter harvest surveys, but those numbers can vary significantly depending on hunter effort. Few hunters actually target spruce grouse, which is perceived to have a “gamier” taste than ruffed grouse. Most are harvested simply as incidental take by ruffed grouse hunters, and hunter effort varies dramatically from year-to-year in northern Minnesota, depending on the ruffed grouse population cycle. That makes it an imperfect gauge of spruce grouse abundance. Since 2006, hunter surveys have suggested that the spruce grouse harvest has ranged from a low of 10,000 to a high of 27,000.
Spruce grouse are a game species in Minnesota, but in neighboring Wisconsin they are listed as threatened, which suggests that Minnesota is on the edge of spruce grouse range. As a species dependent on conifer forest habitat, they are expected to have a smaller range in the future because of climate change-induced habitat loss, and that’s one reason that researchers are seeking better methods for tracking population changes.
“We needed better information about the population to make informed management decisions,” said Charlotte Roy, grouse project leader with the Minnesota DNR. “This survey is expected to detect meaningful changes in the population over a 10-year period.”
The first survey was conducted this past spring, as cooperators from the U.S. Forest Service, northern Minnesota tribes, the DNR, as well as 40 citizen volunteers, including Vermilion Community College students, surveyed 65 routes throughout the conifer forests of northern Minnesota, ranging from Warroad in the northwest to Grand Portage in the east.
“Citizen-scientist volunteers and cooperators are important contributors to the survey. We couldn’t do this survey without their help,” she said.
Survey participants found spruce grouse sign at 88 sites representing 32 percent of those surveyed. More sign was found in the northwest portion of the survey region, primarily that portion of northcentral Minnesota known as “The Big Bog.” Researchers in that area found spruce grouse droppings in 68 percent of the sites they surveyed. The Tower area had the second-highest percentage, with spruce grouse found in 58 percent of the sites visited, while researchers in the Ely area found spruce grouse droppings in 52 percent of sites visited.
Researchers will conduct the survey annually to track population trends and changes in distribution.
The DNR’s 2018 spruce survey report and grouse hunting information can be found at mndnr.gov/hunting/grouse.