Biologists try to ID impacts on grouse

Grouse hunters peg the blame on non-native wild turkeys.

While turkeys have boomed in recent decades, native forest grouse have declined. That’s proof enough for some hunters.

Casual observations offer some credibility to the indictment, but biologists tend to think it’s overblown and detracting attention from the larger problems.

The same discussion endures in eastern states, where wild turkey populations exploded over 30 years while a concurrent and equally spectacular decline occurred in ruffed grouse numbers.

A Spokane hunter recently queried The Ruffed Grouse Society about the turkey versus grouse controversy.

Gary Zimmer, the society’s coordinating biologist, responded with thoughts backed by researchers’ articles. Among his key points:

 • A species that’s expanding its range can hurt an established species, but this rarely happens with turkeys and grouse, which historically have coexisted.

 • Research using radio telemetry or cameras documented that grouse nests suffer predation, but rarely if ever by turkeys.

Scientists in the eastern half of the U.S. conclude that turkeys and forest grouse have largely different habitat preferences and don’t compete for food or space.

“But this is a persistent topic of conversation among biologists as well as hunters,” said Mike Schroeder, state Fish and Wildlife Department wildlife biologist who specializes in grouse.

Schroeder generally agrees with the eastern research, although being a scientist, he wonders if it totally applies to the Northwest.

“We have booming turkey populations in areas with a wide variety of habitats affecting most of these species,” Schroeder said.

But he stops short of concluding that turkeys are crowding out grouse.

“Competition can be indirect,” he said. For example, turkeys could be luring more crows and ravens and other predators might influence the grouse population.

Nonnative species might live with parasites fatal to other species.

Lacking funds for large-scale studies, there’s a lot Schroeder cannot conclude, but he’s confident in listing key pressures affecting Washington’s forest grouse:

 • Landscape level changes. For example, forest fires that exploded since the mid-’90s after decades of fire suppression.

 • Development and rural homebuilding, especially on low-elevation breeding areas for dusky grouse.

 • Changes in forests as logging is followed by reforestation and maturing stands.

 • Pine beetle damage to forests in the Kettle Range and other areas.

 • Impacts on aspen stands, which are important to ruffed grouse. These include fire – or lack of fire – as well as development and grazing – both by livestock and elk.

“The danger is that we just go along not knowing much about the grouse species,” Schroeder said.

“If it’s true the species are headed toward trouble, by the time we figure that out, the only affordable option is to just close down the hunting season.”