What’s Limiting Eastern Ruffed Grouse Populations?

Insights from a career grouse biologist on the factors impacting eastern ruffed grouse survival.

As an aspiring wildlife biologist, I was extremely fortunate to spend a semester of my undergraduate studies in an internship program with Mr. William K. (Bill) Igo, a biologist with the West Virginia Department of Natural Resources (WVDNR). Among the many influences Bill had on my life was his passion for upland game bird biology, management, and hunting. 

Bill and his Brittany gave me a great introduction to ruffed grouse hunting. He sensed my interest and gave me a copy of The Upland Shooting Life by George Bird Evans. Bill was quick to point out that Mr. Evans was somewhat of an enigma for the WVDNR. He was a gifted writer and enthusiast for upland game bird hunting. Evans was a strong critic of late grouse seasons. He maintained that late season hunting suppressed grouse populations. 

Due to his notoriety, Mr. Evans had a lot of influence in his home state of West Virginia. His writings were repeated throughout the region by outdoor writers and avid grouse hunters whenever grouse populations fluctuated. It turned out that his book and theory of hunting effects on grouse shaped my career.

Initial Investigations of Virginia Ruffed Grouse

Following a sharp decline in grouse flushing rates in 1976, the Virginia Game Commission shortened the grouse season by two weeks. Mr. Joe Coggin, then-Supervisor of Game Research, told me George Bird attended the regulation hearings and spoke in favor of a shorter grouse season. But Joe was not sure late season hunting was limiting Virginia grouse. He asked researchers at Virginia Tech to begin an investigation. 

I was fortunate to be the first Virginia Tech graduate student in this investigation. My advisor, Dr. Roy Kirkpatrick, directed me to begin studying the nutritional ecology of grouse in Virginia. I specifically examined food quality and grouse condition. I found grouse were able to build body fats on diets of soft mast in the summer and fall, and acorns in the fall and winter. We hypothesized that winter survival and reproduction could be impacted without high-quality foods.

Years later, I became Virginia’s Ruffed Grouse Project Leader. The question of the impacts of late season grouse hunting persisted in the upland bird hunting community. The fundamental question was whether late season hunting was additive or compensatory mortality. 

Is Late Season Ruffed Grouse Hunting Additive Or Compensatory?

The basis for sport hunting is that hunting losses are compensated by fewer natural mortalities. Thus, post-hunting populations compare to unhunted populations. Wildlife managers also considered a third hypothesis—that hunting was compensatory up to some threshold where it then becomes additive. The obvious concern was that hunting would cause a decline in breeding populations and result in long-term population declines. 

Regrettably, wildlife studies have concluded different results on hunting effects on ruffed grouse populations. One explanation is that ruffed grouse ecology and hunter pressure vary widely across its range. After all, it is the most widely distributed resident game bird in North America. Key factors wildlife managers ideally want to know before drawing any conclusions about hunting impacts include survival rates, hunting mortality rates, and reproductive rates. Knowledge of the impacts of weather, predation, diseases, and habitats on all these parameters are important considerations for managers. Thus, it is understandable that different conclusions have been reported about hunting and other factors limiting grouse populations across the range. 

Nevertheless, decisions must be made about setting seasons, with or without expert knowledge. Criticism and complaints from concerned users come when populations and harvests are less than satisfactory. Joe Coggin had felt the heat. Now it was my turn as concerned grouse hunters continued to raise the question about hunting impacts. 

Concerned hunters wanted to know if those hens harvested in late season would live and reproduce, thereby increasing the population.

The Appalachian Cooperative Grouse Research Project

Together with Jeff Sole, Upland Game Bird Project Leader in Kentucky, we conceived a research project to address these concerns. It took several years of planning and coordination, but we eventually realized our wishful thinking of a cooperative multi-state research project to investigate hunting and other factors limiting grouse populations. 

The project started small, but interest in grouse was high in the region. Eventually, seven state wildlife agencies joined the project. The project was titled the Appalachian Cooperative Grouse Research Project (ACGRP). Six years later, we had caught and radio collared 3,118 ruffed grouse at 12 study sites in eight states. A total of 17 graduate students at eight universities worked on the project.

As part of our primary objective, we closed the hunting seasons at three study sites over the project’s final three years. We compared survival rates in the closed areas to four control sites where hunting continued into February. 

We found no difference in survival rates between hunted and un-hunted populations. In effect, we observed that hens “saved” from hunting were nevertheless subject to high predation rates in March, April, and May. The primary spring predators were hawks and owls. It is important to note that hunting mortality rates in our studies averaged 12 percent. 

Pat Devers, Ph.D. student at Virginia Tech working on the project, wrote, “It is important to recognize that we cannot assume harvest rates higher than those observed in this study are compensatory; nor can we extrapolate our results beyond the Appalachian region.” 

We did find hunting increased grouse winter home ranges.

What Is Limiting Grouse Populations In The Appalachians? 

Surprisingly, we found survival rates in the region were comparable to or even higher than studies from the Lake States and New England. Most of the mortalities were predation, with the greatest losses from avian predators, primarily in the fall and spring. We found Cooper’s hawks and owls were the primary predators.

Reproductive Rates

In contrast, we found reproductive rates in the region were lower. Most notably, chick survival rates and renesting rates were lower in the region’s most abundant forest type, oak-hickory. We found significant annual variation in reproduction in oak-hickory forests that correlated to acorn crops. We noticed hens in these forests tended to forgo nesting in the spring following a poor acorn crop. 

Body Condition

Bob Long, then-M.S. student at West Virginia University (WVU), found that nutrition and pre-breeding condition had a significant impact on reproduction. Bob suggested that hens have a threshold of approximately 11 percent body fat to be successful nesting. 

Weather And Predation

Beyond body condition, weather and predation were responsible for regulating chick survival rates. Using miniature transmitters on grouse chicks, Brian Smith, then-Ph.D. candidate at WVU, found predation and weather were equally responsible for chick losses.

Additional Findings From The ACGRP

In contrast to oak-hickory habitats, grouse in hardwood forests (cherry-maple) in the Appalachians have more reliable food resources and more predictable reproduction. John Tirpak, then-M.S. student at California University of Pennsylvania, found nests in dense understories were more likely to be successful than those in sapling stands and those near openings.

Darroch Whitaker, then-Ph.D. student at Virginia Tech, studied the home ranges and space use of grouse across 10 study sites. He examined 67,814 locations of radio-marked grouse to determine home ranges of more than 1,000 birds. Darroch found that females had larger home ranges than males, juveniles had larger home ranges than adults, and hens with broods used moist bottomlands and riparian areas. He concluded managers should maintain and enhance these critical areas to increase grouse reproduction and grow populations.

Eastern Ruffed Grouse Management Today

The findings from the ACGRP underscored the complexity of ruffed grouse population dynamics in the Appalachian region. While hunting mortality was found to be largely compensatory under the observed conditions, the long-term viability of grouse populations is tied to broader ecological factors, particularly habitat quality and food availability. Today, eastern ruffed grouse management efforts are increasingly focused on addressing these fundamental challenges. 

The “Eastern Ruffed Grouse Conservation Plan (2025-2034)” builds on these insights. The Plan outlines a regional strategy that prioritizes habitat restoration, standardized monitoring, and collaborative conservation efforts across multiple states and provinces.

Ultimately, the future of ruffed grouse in the eastern U.S. depends on a landscape-scale commitment to habitat restoration and adaptive management. Science-driven conservation strategies ensure that management decisions are based on a comprehensive understanding of the species’ needs. By implementing the strategies outlined in the Plan, wildlife managers aim to stabilize and, where possible, rebuild grouse populations for future generations.

“And for so long as the gunner treasures the birds of a paradise and treats them as the fragile things they are,” wrote George Bird Evans, “each covet will belong to him and his dog. Or so he may dream.”