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Ruffed Grouse

Bonasa umbellus
Overview
Minnesota Seasonal Status:

Permanent resident in the forests of Minnesota and a common species during the Minnesota Breeding Bird Atlas (MNBBA).

North American Breeding Distribution and Relative Abundance:

Wide distribution across the boreal forest from the Maritime provinces and the eastern United States to British Columbia and the Pacific Northwest. Southern limits in the Northeast extend into the Appalachian Mountains to northern Georgia; in the Midwest to southern Michigan, Minnesota, and Wisconsin; in the Rocky Mountains to central Utah; and along the Pacific coast to northern California. The species attains its highest densities in western British Columbia. (Figure 1).

Conservation Concern:
Conservation Status Score 9

A game species, the Ruffed Grouse was assigned a Continental Concern Score of 9/20 by Partners in Flight.

Life History
Migration:

Permanent resident.

Food:

Primarily vegetarian, but diet varies by season. In the breeding season, consumes leaves of many herbaceous plants, fruits, and insects; the latter are important to chicks and adults. In other seasons, consumes buds, twigs, catkins, flowers, leafy greens, and acorns. Fond of aspen buds, catkins, and leaves but also uses hazel, willow, and birch.

Nest:

On the ground in a depression with dead leaves, usually near the base of a tree, stump, log, or boulder.

Ruffed Grouse Ruffed Grouse. Bonasa umbellus
© David Brislance
Figure 1.

Breeding distribution and relative abundance of the Ruffed Grouse in North America based on the federal Breeding Bird Survey, 2011–2015 (Sauer et al. 2017).

Minnesota Breeding Bird Distribution*

The Ruffed Grouse is the quintessential upland game bird of Minnesota. Hatch in 1892 in his First Report of the State Zoologist exclaimed, “Nowhere was the Ruffed Grouse more abundant than in all the deciduous forests of this state.” He further said he had reliable reports that its distribution was “from the southern line of the state to the Lake of the Woods in the extreme north.”

Roberts (1932), in his treatise Birds of Minnesota, glorified the bird even more when he said, “Sportsmen will probably agree that the Ruffed Grouse, from every point of view, is the finest upland game-bird belonging to the state of Minnesota, if not the whole of North America.” He described the Ruffed Grouse as breeding in all woodlands of the state and noted that it was highly adaptable to agricultural and urbanized expansions in the early 1900s:

Even with the cutting of the forests and the occupancy of the land, it has maintained a foothold in all available places in the settled portions of the state. Nearly every considerable bit of woodland in the southern part of Minnesota, with anything like wild conditions, still has its breeding Grouse, and scattered pairs may be found even in the environs of our larger cities.

He commented on the “lean” and “fat” periods of its population cycles, which occurred as far back as 1879 without any “special connection with hunting.” He devoted considerable text to the possibility that cycles were related to tularemia (Bacterium tularense), a common disease associated with snowshoe hare. More recent evidence disputes the role of disease in the mortality of wild populations.

Roberts (1932) documented confirmed nests with eggs or young from 1877 to 1924 in Anoka, Becker, Hennepin, Isanti, Marshall, Morrison, Polk, Stearns, and Wright Counties, as well as a covey of young at Itasca State Park. A nest was also documented in Morrison County.

Forty years later and in contrast to Roberts’s optimistic viewpoint of the Ruffed Grouse’s occupancy throughout woodlands of the state, Green and Janssen (1975) limited its range to the “forested portions of the state.” They outlined a distribution that eliminated the southern and southwestern counties west of a line from central Fillmore County to the Twin Cities metropolitan area, west to Swift County and north to central Kittson County. Most of the western tier of counties in Minnesota were not included in the Ruffed Grouse’s distribution. Green and Janssen stated that there had been no reports of the species from Hennepin County for 25 years. They documented confirmed nesting in 31 counties, all within forested areas of the state.

Janssen (1987) described a Ruffed Grouse distribution similar to that reported by Green and Janssen (1975) but with potential extensions west into Rice County (Nerstrand Woods State Park) and eastern Steele County. He also reported a reintroduction of the species into the Hennepin County Park system in 1972, which produced some success, as documented by Sivets (1975) in Morris Baker County Park in 1974, and by Gillette (1976) in Elm Creek, Baker, and Crow-Hassan Park Reserves from 1974 to 1976. Janssen reported confirmed nesting records in 36 counties since 1970. The counties encompassed the same general range as Green and Janssen’s (1975) distribution but extended the western boundary to include Becker County and northeastern Grant County. Hertzel and Janssen (1998) reported 42 counties with confirmed nesting records since 1970 when they added Fillmore, Kandiyohi, Olmsted, Pennington, Roseau, and Winona Counties to Janssen’s 1987 list.

The Minnesota Biological Survey reported 304 breeding season locations, which were consistent with the ranges described by both Green and Janssen (1975) and Janssen (1987), except for 1 location in Nicollet County in southern Minnesota (Minnesota Department of Natural Resources 2017a). Locations were numerous in many counties, including in Aitkin, southern Beltrami, southern Cass, Clearwater, Cook, Houston, northern Lake, Itasca, Marshall, northwestern Morrison, Otter Tail, Pine, northern St. Louis, and Winona Counties.

The participants in the MNBBA reported 2,239 records, which corresponded well with what had been previously described by Green and Janssen (1975) and Janssen (1987) (Figure 2). Ruffed Grouse breeding evidence was found in 26.0% (1,272/4,899) of all blocks surveyed and in 26.1% (610/2,337) of priority blocks (Figure 3; Table 1). By far, most of the breeding evidence records were of probable nesting, in 51.2% (651 of 1,272) of all blocks with records. Confirmed nesting was found in 227 blocks and 32 counties, including 2 counties (Chisago and Todd) that were not previously reported by Hertzel and Janssen (1998). Breeding records were particularly dense in the northeastern and northern regions of the state, basically north from northern Mille Lacs County to central Becker County and east from eastern Marshall and eastern Roseau Counties. Observations were lacking from the Twin Cities metropolitan area, including Hennepin, Ramsey, and the western metropolitan counties of Carver and Wright.

The landcover suitability map for the Ruffed Grouse illustrates that the most suitable habitat for the species is northeastern Minnesota, with suitability decreasing to the west and to the south (Figure 4). Sparse populations are predicted in southeastern Minnesota and in extreme northwestern Minnesota.

Changes in the Minnesota distribution of the Ruffed Grouse have primarily been retractions from the southwest, south, and western margins of its former range reported by Roberts (1932). In their review of the Ruffed Grouse in North America, Rusch et al. (2000) said these retractions were widespread throughout many areas, including riparian woodlands of the Dakotas, eastern Iowa, eastern Kansas, and Nebraska. Further, Ruffed Grouse once occupied all of Ohio, Indiana, Illinois, Missouri, northwest Arkansas, western Tennessee, western Kentucky, eastern Maryland, and eastern Virginia. In many of these areas, Ruffed Grouse have been reintroduced. Roberts (1932) reported individuals or populations being maintained in fragmented woodlands in the southwest and in the Twin Cities metropolitan area, often following reintroductions. These were likely what we now call “sink” populations, in which reproduction is highly variable or very poor and which require constant recolonization from other “source” populations or restocking programs.

Historical changes in the Ruffed Grouse’s distribution were largely due to land clearing for agriculture and settlements, the consequent reduction in contiguous forest habitat, and market hunting (e.g., Rusch et al. 2000). Schorger (1945) described presettlement fires that maintained oak-dominated forest types in southern Wisconsin and higher grouse densities in the south. Settlements and agriculture in the latter 1800s and early 1900s resulted in reduced forest area in southern areas of the state. Increased logging in the northern forests, formerly dominated by conifers and northern hardwoods, created more habitat and increased populations in northern Wisconsin. Regenerating forests with increased aspen and birch cover types also provided a better food source for the species. Similar retractions of the species’ range from the south portions of Ontario (Cadman et al. 1987) and Michigan (Brewer et al. 1991) have also been documented.

*Note that the definition of confirmed nesting of a species is different for Breeding Bird Atlas projects, including the definition used by the Minnesota Breeding Bird Atlas, compared with a more restrictive definition used by the Minnesota Ornithologists’ Union. For details see the Data Methods Section.

Figure 2.

Breeding distribution of the Ruffed Grouse in Minnesota based on the Breeding Bird Atlas (2009 – 2013).

Print Map
Figure 3.

Summary statistics of observations by breeding status category for the Ruffed Grouse in Minnesota based on all blocks (each 5 km x 5 km) surveyed during the Breeding Bird Atlas (2009-2013).

Breeding statusBlocks (%)Priority Blocks (%)
Confirmed227 (4.6%)120 (5.1%)
Probable651 (13.3%)255 (10.9%)
Possible389 (7.9%)232 (9.9%)
Observed5 (0.1%)3 (0.1%)
Total1,272 (26.0%)610 (26.1%)
Table 1.

Summary statistics for the Ruffed Grouse observations by breeding status category for all blocks and priority blocks (each 5 km x 5 km) surveyed during the Minnesota Breeding Bird Atlas (2009-2013).

Figure 4.

Predicted breeding distribution (birds detected per 10-minute point count) of the Ruffed Grouse in Minnesota based on habitat, landscape context, and climate data gathered during the Minnesota Breeding Bird Atlas (2009-2013) using the General Linear Modeling method without an adjustment for detectability.

Breeding Habitat

Substantial literature has accumulated on details of the breeding habitat for this species. Rusch et al. (2000) summarized that highest densities in the midwestern states are in aspen-dominated forests with a mixture of young and older forests that provide cover and food. Further, they suggest that large, contiguous blocks of upland aspen and oak forest are preferred to smaller, isolated or fragmented woodlots surrounding agricultural fields. In Minnesota, Ruffed Grouse were also found in mixed deciduous-coniferous forests but in lower densities (Gullion and Marshall 1968; Gullion and Alm 1983). The Minnesota Department of Natural Resources (2017b) found that young to middle-aged aspen forests were the best habitat and that alder lowlands and patches of gray dogwood were attractive in summer and fall.

Vegetation structure around nest sites is generally described as hardwood or aspen stands with open understories that provide good visibility to detect ground predators, and dense overstory cover for protection from aerial predators (Rusch et al. 2000).

Drumming sites include young hardwood forests where stem densities are high, providing overstory cover but good visibility at ground level. Gullion (1970) quantified these sites in Minnesota. Densities of understory stems ranged from 30,000 to 33,000 stems per ha, and drumming logs were typically 20 cm in diameter and greater than or equal to 2 m in length (Gullion 1967). There were generally 1 to 2 logs per territory. Other objects, such as large boulders, mounds of dirt, exposed tree roots, and other structures that elevate grouse above the ground, were also used. Rusch et al. (2000) concluded that the lack of drumming logs or platforms was not likely to limit the distribution of grouse.

Green (1995) discussed the Ruffed Grouse’s need for edges and maintained that labeling it as an “edge species” was erroneous and the result of poor definition and misunderstanding. She quoted the following from Gullion (1984, 74-75):

Ruffed grouse have usually been included among the species for whom the development of a great deal of ‘edge’ is beneficial. However, when we take a closer look at what happens at the edges where ruffed grouse concentrate, and why the birds are there, the story takes a different slant. Actually, extensive use of forest edges by ruffed grouse provides the best indication of how unsatisfactory a forest habitat has become for these birds. When grouse must depend upon edges to find the resources they need it means that the rest of the forest is deficient in those resources, and the quality of the habitat has deteriorated to such a state that only a small portion remains acceptable.

Habitat analysis from the National Forest Bird (NFB) Monitoring Program (Niemi et al. 2016) indicated that the species was found in a variety of forest cover types during the breeding season in June, including aspen-birch, aspen-spruce-fir, lowland hardwoods, mixed swamp-conifer, and upland hardwoods. The analysis was primarily based on drumming counts but points out the species’ wide breeding habitat distribution and used a large, probability-based sample (n = 1,128; detections at 486 sample points). Habitat data gathered where Ruffed Grouse were detected during the MNBBA point counts indicated wide use of land cover types, including upland coniferous forests, northern mixed forests, lowland coniferous forests, and pine-oak barrens (Figure 5).

The effect of landscape fragmentation on Ruffed Grouse populations has been raised as a concern. North and Faber (2014), in their evaluation of the effect of the Twin Cities metropolitan area on regional distributions of breeding birds, noted the lack of Ruffed Grouse populations in the metropolitan area. They were concerned that the region may serve as a bottleneck to dispersing Ruffed Grouse and prohibit gene flow between populations in the north and those in southeastern Minnesota. Small et al. (1991) had previously raised concerns about Ruffed Grouse and fragmented habitat in Wisconsin based on a study of 381 radio-marked grouse. They found that immigration from private lands was important to maintain populations of grouse on public lands because mortality from both predation and hunting were high on public lands but only predation was high on private lands. Fragmented landscapes and the Ruffed Grouse’s low ability to disperse could increasingly have substantial effects on populations by reducing colonization.

Rusch et al. (2000) emphasized that optimal year-round cover included a mixture of young and older forests. Furthermore, contiguous blocks of upland aspen and oak forests were better than smaller, isolated or fragmented woodlots surrounded by agricultural fields.

Figure 5.

Habitat profile for the Ruffed Grouse based on habitats within 200 m of point counts where the species was present during the Minnesota Breeding Bird Atlas (2009-2013).

Population Abundance

Partners in Flight estimated a United States and Canadian population of 18 million adults (Rosenberg et al. 2016). Partners in Flight also estimated that the population had increased by 31% from 1970 to 2014. The North American Breeding Bird Survey (Sauer et al. 2017) was unreliable for detecting population trends because most counts are completed after the primary drumming season is over.

The Minnesota Department of Natural Resources has completed spring roadside Ruffed Grouse drumming counts in Minnesota since 1949. Routes consist of 10-4 min listening stops at 1.6-km intervals. The counts are completed in April or May. Statewide trends have been relatively stable from 1949 to 2016. Peaks generally occur about every 10 years (Figure 6). The population index for the Ruffed Grouse in southeastern Minnesota has been relatively low since 1991. The population cycles are less pronounced southward from the northeastern region, where they are most evident, and they are nonexistent in the southeast (Bergerud 1988; Roy 2016). Annual harvest of Ruffed Grouse in Minnesota averages slightly over 500,000 birds (range of 150,000 to 1.4 million) (Roy 2016).

Rusch et al. (2000) stated that average recorded densities are about 3 drumming males or 9 adults per 40 ha (100 acres) in spring but suggested these are overestimates because studies have been completed primarily in good habitat. They also surmised that densities during the peak of the cycles in Minnesota and Wisconsin were likely about 20 birds per 400 ha. Dessecker et al. (2006) estimated male drumming densities by habitat type in the Great Lakes region, which varied from 0.5 drumming males per 40 ha in pine forests to 3.5 drumming males per 40 ha in aspen-birch forest types. Home ranges of the Ruffed Grouse based on telemetry of 13 hens in Minnesota ranged from 2 to 14 ha (Maxson 1989).

Figure 6

Statewide population index values for Ruffed Grouse in Minnesota (95% bootstrapped confidence intervals have been used since 1981; different methods were used prior to 1981; Roy 2016).

Conservation

Partners in Flight assigned a moderate Continental Concern Score of 9/20 to the Ruffed Grouse (Rosenberg et al. 2016). Overall the species still has a relatively large population, wide distribution, and a stable or possibly increasing population in North America. Strategic efforts to improve populations of the Ruffed Grouse have been developed by the Ruffed Grouse Society (Dessecker et al. 2006) and specifically for Bird Conservation Region 12, which includes Minnesota. The plan calls for restoring its population to levels observed in 1980 by 2025. The year 1980 was selected because it represents a point in time when population levels were considered “normal.” Prior to this time, in the early to mid-20th century, populations were considered to be higher than historically normal because of the creation of excessive early-successional vegetation and abandonment of farms during the early 1900s.

Regulated hunting has not been considered to be a problem in maintaining population levels of the species (Rusch et al. 2000). Historically, however, hunting did decrease populations in the late 1800s and early 1900s. In Minnesota, Hatch (1892) described the Ruffed Grouse as “mercilessly slaughtered by pot-hunters,” and he wrote that “their [Ruffed Grouse] ‘glorious day is passing away’ as fast as about 300 dogs and 700 double-barreled breech-loading shotguns can accomplish their annihilation.” Schorger (1945) in Wisconsin described that shooting of grouse for subsistence and sale was common through the early 1900s. For instance, 600 grouse per day were shipped to markets in Milwaukee in 1898.

Considerable land is available for hunting Ruffed Grouse in Minnesota, and many conservation efforts have been implemented to maintain population levels. The Minnesota Department of Natural Resources (2017c) states that there are 11 million acres of public hunting land, 528 designated hunting areas covering nearly 1 million acres, more than 40 designated Ruffed Grouse management areas, and 600 miles of hunter walking trails. The Ruffed Grouse Society identified over 100 management areas and special projects dedicated to Ruffed Grouse restoration and management between 1985 and 2010. Clearly, many of these areas provide extensive benefits to many other wildlife species as well.

Rusch et al. (2000) summarized the major issues for the future of the Ruffed Grouse as the following: maturation of the forests, especially in the eastern United States; forest fragmentation and lack of connectivity among forest tracts; management of hunting of small, isolated populations of Ruffed Grouse; future effects of pesticide use in agricultural regions and in forestry; and the need for an improved understanding of the genetic structure of Ruffed Grouse.

In 2000, when Rusch et al. published their review, no mention was made of climate change. However, Langham et al. (2015) and the National Audubon Society (2015), in their review on the effects of climate change on birds in North America, identified the Ruffed Grouse as “climate endangered.” The society predicted that Ruffed Grouse would lose 34% of its breeding range by 2080. Moreover, their model predictions suggest that the species will no longer exist in the lower 48 states by the end of this century.

Like so many other bird species, the Ruffed Grouse has an unclear future in the long term in Minnesota. Its future will depend on the decisions that society makes regarding its use of natural resources and the factors that are known to affect those resources.

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