Ruffed grouse are found throughout Canada and in 38 of the 49 continental United States. In the east they extend as far south as northern Georgia. In the western states ruffed grouse are found along the western slopes of the Cascades into northern California and in the Rocky Mountains into Wyoming and central Utah. In the central United States isolated populations persist in the Dakotas and as far south as Arkansas. Populations have been introduced into Newfoundland and Nevada.
Biogeographic Regions: nearctic (Native )
I first experienced the Ruffed Grouse when I was about six, and I was wandering about in my uncle's woods. I was startled by the characteristic "drumming" sound. Since then, I have heard the noise several times, in various wooded areas.
Perception Channels: visual ; tactile ; acoustic ; chemical
The Ruffed Grouse is hunted for sport, but it is far from being endangered. The only real requirement that the Ruffed Grouse needs is a forested region, so this is another animal that could be affected by extensive deforestation.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Some farmers are troubled by these birds, because they are primarily fruit eaters.
Leonard, 1973.
The Ruffed Grouse is hunted for sport, so areas that have very dense populations of the bird benefit from extra tourism during the hunting season
Also, The Ruffed Grouse hatchlings are mainly insectivorous, so the insect populations in some area decrease shortly after the hatching season.
Peterson, 1980.
Over one-fourth of the Ruffed Grouse's diet is made up of fruit, such as thorn apples, blueberries, strawberries. It also eats wild and cultivated sunflower seeds, birch, poplar, and willow buds. The Christmas Fern is also a special food for the Ruffed Grouse.
Young Ruffed Grouse Chicks are primarily insectivorous, until they are old enough to care fo r themselves.
Birds of America, 1940.
The Ruffed Grouse prefers forested areas in rough, cold lands. It also prefers dim and quiet woods, deep thickets, or sheltered swamps. The Ruffed Grouse doesn't like open fields, and will rarely, if never, be found there.
Pearson,1940.
Terrestrial Biomes: forest
Average lifespan
Status: wild: 102 months.
The Ruffed Grouse is approximately 18 inches in length. The color is two-toned reddish-brown and spotted on the back, and yellowish with dark bars beneath. The tail has 18 broad feathers, which appear to be half-diamond shaped when spread. The tarsus is partly feathered.
Pearson, 1940.
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 644 g.
Average basal metabolic rate: 2.3894 W.
The Ruffed Grouse is a ground nesting bird. The female lays one egg per day, until her clutch is complete. The average clutch is about 11 eggs. The female sits on the eggs, in the nest, until the eggs hatch, after 23 to 26 days. Fledging occurs after 8 to 10 weeks.
Pearson, 1940, USDA Forest Service 2001.
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average time to hatching: 24 days.
Average eggs per season: 11.
Average age at sexual or reproductive maturity (male)
Sex: male: 120 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 120 days.
Well-adapted to living on the forest floor, the Ruffed Grouse is mottled brown-and-gray on the back and barred brown-and-gray below. This species may also be identified by its large size (16-19 inches), black-banded tail, and the ruffled head and feathers on its neck and head. Two color morphs occur, a northern morph with a gray tail and a southern morph with a rusty-red tail. Female Ruffed Grouse are slightly smaller than males, and have smaller quantities of ruffled feathers. The core range of the Ruffled Grouse is centered on southern Canada, extending north to the Arctic Circle in Alaska and south along higher elevations of the Appalachian and Rocky Mountains as far as North Carolina and Utah, respectively. Several conservation programs have led to the reintroduction of this species into isolated locations in the southern portion of its range, where it was once more common. The Ruffed Grouse is a permanent resident across its range. Ruffed Grouse inhabit cool evergreen and mixed evergreen and deciduous forests. Plant matter, including seeds, buds, leaves, and berries, make up a large proportion of this species’ diet. However during the warmer months (and particularly during breeding), insects are consumed when available as a source of protein for chicks and adults alike. Ruffed Grouse may be observed while foraging for food on the forest floor or while roosting in trees at dawn or dusk. During the early part of the breeding season, males may be heard making loud drumming noises with their wings as part of their mating and territorial display. This species is primarily active during the day, but males may drum on clear nights after dark or in the morning before dawn.
Well-adapted to living on the forest floor, the Ruffed Grouse is mottled brown-and-gray on the back and barred brown-and-gray below. This species may also be identified by its large size (16-19 inches), black-banded tail, and the ruffled head and feathers on its neck and head. Two color morphs occur, a northern morph with a gray tail and a southern morph with a rusty-red tail. Female Ruffed Grouse are slightly smaller than males, and have smaller quantities of ruffled feathers. The core range of the Ruffled Grouse is centered on southern Canada, extending north to the Arctic Circle in Alaska and south along higher elevations of the Appalachian and Rocky Mountains as far as North Carolina and Utah, respectively. Several conservation programs have led to the reintroduction of this species into isolated locations in the southern portion of its range, where it was once more common. The Ruffed Grouse is a permanent resident across its range. Ruffed Grouse inhabit cool evergreen and mixed evergreen and deciduous forests. Plant matter, including seeds, buds, leaves, and berries, make up a large proportion of this species’ diet. However during the warmer months (and particularly during breeding), insects are consumed when available as a source of protein for chicks and adults alike. Ruffed Grouse may be observed while foraging for food on the forest floor or while roosting in trees at dawn or dusk. During the early part of the breeding season, males may be heard making loud drumming noises with their wings as part of their mating and territorial display. This species is primarily active during the day, but males may drum on clear nights after dark or in the morning before dawn.
The major source of ruffed grouse mortality is predation [22,34,156]. Hunting can result in high levels of mortality, but in most areas hunting pressure does not negatively impact ruffed grouse populations [22,24,34,101,156].
Diseases and parasites are common in ruffed grouse, but they do not result in substantial mortality [24,156]. Common parasites are ticks (Ixodida) and worms such as stomach worms (Dispharynx nasuta) and tapeworms (Cestoda) [156]. Immature birds are generally more frequently and severely affected [24]. Diseases that most commonly resulted in mortality in New York were quail disease (ulcerative enteritis), blackhead (histomoniasis), and aspergillosis (Bump and others 1947 cited in [24]). Grange [57] asserts that, in at least some instances, fire controls ruffed grouse diseases and parasites, such as ticks (see Indirect Fire Effects: Ruffed grouse populations and occurrence).
Ruffed grouse densities are low in the southern portions of the range [24,192]. Based on a summary of several surveys of drumming males in the Central Hardwoods region, densities were less than 2 males/100 acres (40 ha) in Georgia, Tennessee, Kentucky, and Missouri. In Indiana, Ohio, and Iowa, densities ranged from about 1 to 3 males/100 acres. In Wisconsin and Minnesota, densities ranged from 2 to 9 males/100 acres [192]. See Plant associations used as habitat for information on the effect of plant communities on ruffed grouse densities.
Densities of ruffed grouse decline from a peak in the fall, following recruitment of new chicks, to a low in spring, following winter mortality. Fall densities range from 4.9 to 28.6 ruffed grouse/100 acres, while spring densities range from 1.4 to 7.4 ruffed grouse/100 acres [24].
Adult ruffed grouse are unlikely to suffer directly from fire. It is generally accepted that large, fast-moving fires may result in mortality, and mortality of ruffed grouse adults due to fire has been documented [57], but birds typically have the mobility to avoid fire [21,35,149]. Ruffed grouse mortality rates did not differ before and after a moderate to severe May wildfire in Alberta [37].
Ruffed grouse are most vulnerable to fires in the nesting season [37,57,177]. A moderate to severe May wildfire in Alberta resulted in near complete nest destruction, as evidenced by the absence of the typical summer population peak, higher ratios of brood to single ruffed grouse flushes in unburned areas than burned areas, a lack of juveniles trapped from August to November, and a lack of young males trapped the following spring [37]. On a site in eastern Ontario, only one ruffed grouse egg was observed within a 939-acre (380 ha) burned area 2 days after a severe late May wildfire [177]. Grange [57] states that fires from May to July in Wisconsin eliminate ruffed grouse production in that year and that April fires may have the same effect, depending on their timing relative to the start of nesting. Literature reviews have used life history characteristics to speculate on possible effects of fire on nesting success and bird populations [128,152]. Since ruffed grouse nest on the ground, fires of any severity during the nesting season are likely to result in considerable nest mortality. However, the degree to which a population would be affected by fire would depend on several factors in addition to season, including occurrence of renesting, fire-return interval, fire uniformity, and fire severity. The limited amount of ruffed grouse renesting in some areas (see Reproductive output) suggests that recruitment for the year could be substantially reduced even if fires occurred early in the nesting season.
Ruffed grouse use of burned areas is variable. Within 48 hours of a moderate to severe May wildfire in Alberta, about 50% of the population had emigrated from a burned area that had been comprised of quaking aspen stands, black spruce stands, bogs, and open land. About 50% more females left the burned areas than males [37]. Within a month of a 939-acre (380 ha) late May wildfire in eastern Ontario, 1 ruffed grouse was observed along 2 transects in the burned area, and 7 were observed along 2 transects in the in the unburned area [177]. Similarly, ruffed grouse were heard drumming in unburned patches a week after a mixed-severity May wildfire burned 15,000 acres (6,070 ha) in northeastern Minnesota [182]. In contrast, in the 30 days following small, late April and early May prescribed fires performed in New York in an open herbaceous community with some shrubs and trees, there were 15 times as many ruffed grouse droppings in burned as in control areas. This difference was apparent within 48 hours of burning [44]. Grange also notes that ruffed grouse occasionally occur in abundance in burned areas in Wisconsin [57]. Sharp [169] noted that ruffed grouse may be attracted to areas burned before 15 April.
Juvenile ruffed grouse disperse in fall [24,156]. In northern Michigan in fall, juvenile dispersal was generally more common than adult dispersal [22]. In Wisconsin, juvenile dispersal occurred from September to early October (Small and Rusch 1989 cited in [156]). From March to early April, dispersal was observed primarily in male yearlings (Small and Rusch 1989, Rusch personal observation cited in [156]). Dispersal distances are typically a few miles, although in Alberta the average movement of recaptured ruffed grouse banded as chicks was 387 feet (118 m). Only 5 ruffed grouse were recaptured more than 2,625 feet (800 m) from the banding site (Rusch and Keith 1971b cited in [156]).
Females disperse farther than males [22,156]. From fall to spring in Wisconsin, average dispersal distance was 1.5 miles (2.4 km) for male chicks and 3 miles (4.9 km) for female chicks (Small and Rusch 1989 cited in [156]). In West Virginia, average dispersal distance was 1.5 miles for 6 juvenile males and 2.2 miles (3.5 km) for 11 juvenile females (Plaugher 1998 cited in [156]). In Alberta, adult male (n=60) movements from spring to fall averaged 689 feet (210 m); during the same period movements of 7 females averaged 1,644 feet (501 m) (Rusch and Keith 1971b cited in [156]). In northern Michigan, female dispersal in the fall was generally more common than male dispersal. However, there was variation among years and across sites [22].
Ruffed grouse is a widespread, year-round resident of North America. It occurs throughout much of Canada from western Labrador and New Brunswick west to British Columbia, southern and central Northwest Territories, and southern and western Yukon Territory. Ruffed grouse was successfully introduced to western portions of Newfoundland. In the United States it occurs in central Alaska, northern portions of the West, the Midwest, and in the East from New England south to the Appalachian states. In the West, ruffed grouse occurs in Washington, Oregon, northwestern California, Idaho, western and central Montana, northwestern Wyoming, northeastern and central Utah, small areas of northern North Dakota, and the Black Hills region of South Dakota and adjacent Wyoming [156]. In the Midwest, ruffed grouse occupies much of Minnesota, Wisconsin, northeastern Iowa, Michigan, southern portions of Indiana, and southern and eastern portions of Ohio. Ruffed grouse occur throughout New England. From there its distribution extends southwest through Pennsylvania, West Virginia, western Virginia, and eastern Kentucky to the border of Tennessee and North Carolina [156]. Birds of North America provides a distributional map of ruffed grouse.
Ruffed grouse have been introduced in Nevada [137]. They have been reported in extreme northwestern Colorado [16]. A ruffed grouse nest was observed in South Carolina in 2000 [90], and ruffed grouse may also occur in northeastern Alabama [156]. Restored populations occur in Arkansas, Kansas, Illinois, and Missouri [156].
The ruffed grouse was historically more widespread in riparian areas of the Northern Great Plains, including the Dakotas, Kansas, and Nebraska, and it occurred throughout Ohio, Indiana, Illinois, Iowa, and Missouri, as well as areas in northwestern Arkansas, western Tennessee, western Kentucky, eastern Maryland, and eastern Virginia [156].
States and provinces (as of 2011 [137]):
United States: AK, AL, AR, CA, CO, CT, GA, IA, ID, IL, IN, KS, KY, MA, MD, ME, MI, MN, MO, MT, NC, ND, NH, NJ, NV, NY, OH, OR, PA, RI, SC, SD, TN, UT, VA, VT, WA, WI, WV, WY
Canada: AB, BC, LB, MB, NB, NL, NS, NT, ON, PE, QC, SK, YT
Generally speaking, periodic [60,202] fires that burn patchily [57] (see Landscape-level requirements) and occur in early spring (see Direct Fire Effects) are less likely to have detrimental impacts on ruffed grouse in the short term than fires that are large, uniform, and/or occur soon after another fire or during the nesting or brooding seasons. Over long time frames, ruffed grouse's response to a fire in a particular location is likely to depend on what factors are limiting ruffed grouse in that area [141]. For instance, if a lack of early-successional habitat is limiting ruffed grouse, development of adequate cover about 10 years following a fire would benefit the population (see Indirect Fire Effects: Habitat). In contrast, if winter forage (see Temporal and spatial variation in the diet) is limiting, a fire that reduces food producing trees would likely be detrimental to the population. See Habitat management considerations for a broader discussion of retaining food-producing trees.
Restricting burning during the nesting and brooding seasons is widely recommended [57,64,103,141,169]. Grange [57] recommends burning in early spring, because it likely reduces impacts on breeding and vegetation generally recovers quickly. In the Appalachians, burning before nest initiation in early to mid-April was stressed, since the renesting rate was low [141]. The suggested cutoff for burning oak-hickory communities in Pennsylvania was 15 April; fires after this date would likely result in lost nests or high chick mortality [169]. Similarly, Jones and others [103] recommend burning before the mean nest initiation date, which was 16 April in the central and southern Appalachians (Devers 2005 cited in [103]). Spring slash burning is recommended in harvested aspen stands, although burning in fall may also be effective [64].
Adjusting fire severity and frequency may meet ruffed grouse's various habitat needs and address issues arising from differences in site characteristics [141]. Low-severity surface fire may reduce litter and increase herbaceous species in the understory, while a comparatively severe fire that opens the canopy may increase soft mast production. Severe fires that substantially reduce canopy cover have been recommended for creating brood habitat [141]. Interspersion of different fire frequencies has been recommended for providing brood habitat in oak-hickory forests of West Virginia [153], and varying fire temporally across the landscape was recommended to increase forage production in oak-hickory forests in Pennsylvania [169]. On oak-hickory sites in West Virginia, burning some sites every year and other sites every 3 years provided good supplies of both insect and plant foods [153]. On dry sites in oak-hickory forests of North Carolina, prescribed fire every 2 to 4 years may increase herbaceous cover [141]. Based on observations in oak-hickory communities in Pennsylvania, burning sedge communities every 2 years and areas with high cover of blueberries every 4 or 5 years on a rotation—so that some blueberries produce fruit every year—may increase forage production [169]. Rotation lengths of 60 years have been recommended in western quaking aspen forests, whether harvesting or burning. In these areas, burning a 10-acre (4 ha) unit every 15 years would provide the diversity of age classes needed within typical movement distances of ruffed grouse [28]. Fires every 20 to 25 years were recommended for young boreal forest stands (Gullion 1971 cited in [24]). Other site factors that are likely to influence rate of regeneration and the appropriate fire frequency include elevation [190] and site quality [32].
Fires of about 10 acres (4 ha) that create interspersed stands of varying ages have been recommended for pine forests of Minnesota [97], quaking aspen forests in the West [28,55], and in the boreal region (Gullion 1971 cited in [24]). Similar sizes are recommended for clearcuts in aspen, where about 10 acres of a 40- to 50-acre (16-20 ha) management unit are treated every 10 to 15 years (see Habitat management considerations). Larger fires may be appropriate for setting back succession in coniferous forests (Stauffer and Peterson 1982 cited in [28]). Based on the daily ruffed grouse movement rate of 1 mile (0.6 km) (Trippensee 1948 cited in [97]), Irving [97] suggests that burns greater than 40 acres (16 ha) could have negative impacts on ruffed grouse. Large fires would likely have detrimental impacts on habitat interspersion [97], which is an important ruffed grouse habitat characteristic [169] (see Landscape-level requirements). Uniform fires larger than 40 acres would likely be more detrimental than patchy fires. However, in areas where conifers are establishing, burning large areas may produce habitat that can be later be added to units being managed in rotation (Stauffer and Peterson 1982 cited in [28]). Sharp [169] recommended varying fire both temporally and spatially for oak-hickory forests in Pennsylvania. Similarly, Jones and Harper [102] recommended varying the size of clearcuts in the Appalachians from about 2 to 40 acres (0.8-16 ha) to benefit ruffed grouse.
Prescribed fires can be placed so that mesic communities serve as firebreaks. This would result in a mosaic of postfire habitats favoring ruffed grouse [141]. Strategies mentioned for arrangement of clearcuts, such as performing cuts on midslopes (see Habitat management considerations), may also be relevant for burning.
Fire is often recommended in conjunction with timber harvesting [183] to reduce canopy cover [159] and excess logging slash [64]. Gullion [64] considered fire the most ecological way to treat slash and recommended burning following intensive timber management whenever practical [64]. Burning within a year of timber harvest has been recommended to improve brood habitat (Sharp 1970 cited in [28]). Burning should be completed by the 2nd growing season following harvest, or the density of aspen suckers could be reduced [64]. When burning failed to impact large hardwood trees on 4 sites in Minnesota, Sando [159] recommended thinning before burning to stimulate aspen reproduction and reduce overstory cover. Burning after thinning may produce good brooding conditions [103,141].
Ruffed grouse density or occurrence in harvested areas is typically similar to [96,162] or insignificantly greater than in burned areas [87,163,187,200]. This pattern suggests that for ruffed grouse Habitat management, tree harvest may be an adequate surrogate for fire [163]. However, while recognizing fire's limitations, Gullion [64] considered mechanical treatments a poor second choice to fire. Based on a meta-analysis of data from boreal forests, ruffed grouse were common in 11- to 30-year-old forests whether they were burned or harvested. Ruffed grouse were uncommon in harvested forests ≤10 years old and in burned forests ≤10 years old that had live trees remaining on the site. Ruffed grouse were rare in burns ≤10 years old that had no live trees remaining [162]. Ruffed grouse detections were similar in stand-replacement burns and in fairly recent, shrubby clearcuts in northern Idaho and western Montana. However, the variation in detections in stand-replacement burns was large [96]. In the Engelmann Spruce-Subalpine fir dry cool biogeoclimatic zone in eastern British Columbia, ruffed grouse were observed at an average of 2 individuals/km² in burns and 4 individuals/km² in logged areas. In the Montane Spruce dry cool biogeoclimatic zone of the same area, ruffed grouse did not occur on burned sites of any age and occurred at an average of 2/km² in 7- to 16-year-old forests, 7/km² in 17- to 26-year-old forests, and 3/km² in 27- to 45-year-old forests that were logged. The statistical significance of these differences was not tested [187]. In boreal forest mosaic of quaking aspen, black spruce, white spruce, jack pine, balsam poplar, and paper birch in Alberta, density of ruffed grouse was similar on burned and harvested sites, ranging from 0 to 3.7 in 25 acres [87]. In Minnesota, density of ruffed grouse was similar in early-successional logged habitat and in early-successional habitat that burned in a 5,200-acre (2,100 ha) May wildfire [163].
Use of fire may be limited by site conditions. For instance, Whitaker and others [204] found that oak-hickory forests in West Virginia were commonly not within the prescribed range of conditions for burning. Furthermore, the prescribed conditions may not have produced the kind of fire behavior needed to improve habitat; vegetation on a burn performed within prescribed conditions in a dry year recovered more slowly than desired [204].
Nutritional content, levels of protective plant chemicals, and ease of obtaining food influence the value of forage for ruffed grouse. High levels of metabolizable energy and protein and low levels of plant protective chemicals increase ruffed grouse forage quality. Ruffed grouse avoid plants with high levels of tannins [167], coniferyl benozoate [59,98,99], and other protective chemicals [167]. Table 3 ranks various food types by 3 nutritional factors. The availability of large aspen buds during winter and the ease of harvesting them from sturdy terminal branches may help explain ruffed grouse selection of aspen buds over other available species with seemingly better nutritional value [38,192]. For instance, ruffed grouse selected aspen over willow buds that had higher protein levels during winter in Alberta [38]. Based on information about diet, foraging, and models developed from observing captive ruffed grouse forage, Hewitt and Kirkpatrick [83] estimate that ruffed grouse eating aspen for 30 to 50 minutes can obtain the same amount of metabolizable energy as ruffed grouse eating a combination of evergreen and herbaceous leaves and fruits for 100 minutes. In winter in Alberta, ruffed grouse selected aspen buds with more protein and potassium levels than aspen buds not eaten, suggesting that these nutrients influence food selection [38].
Table 3. Typical forage quality of various food types [167] Metabolizable energy Protein levels Protective chemicals Herbaceous leaves high high low Acorns high high variable Buds and catkins low intermediate intermediate Soft fruits high low low Evergreen leaves low low highForage quality may explain some of the differences between ruffed grouse population performance in different regions. High levels of evergreen forage [85,124,167], soft fruits, and tannins [167] in the diet suggest ruffed grouse in the Southeast may have poor winter diets that lack protein. Larger home ranges in oak-hickory than mixed-mesophytic forests, larger home ranges in oak-hickory communities following poor mast crops [206], and differences in ruffed grouse habitat selection in oak-hickory compared to mixed-mesophytic forests [205] suggest that nutritional stress may be greatest in oak-hickory forests. In low-acorn producing years, these communities lack high-quality alternatives to acorns, such as cherries and birch catkins and buds [206]. On an oak-hickory site in southwestern Virginia, carrying capacity was low due to scarcity of high-quality winter forage [85], and throughout the region ruffed grouse fat reserves declined during winter and spring [140].
Diet quality may influence ruffed grouse recruitment. Mast production may influence fat levels in ruffed grouse, but there are contradictory results regarding whether carcass fat has positive [125] or no [148] influence on fecundity and recruitment. Beckerton and Middleton [6] found a positive correlation between protein level in the diet and clutch size, clutch weight, hatching success, chick weight, and survival of chicks to 9 weeks (P<0.025). The possibilities of lower chick survival and recruitment in southern populations ([34,198], Davis and Stoll 1973 cited in [24]) (see Plant associations used as habitat), low winter protein levels for ruffed grouse in some southern plant communities [124,167], and the association between protein level and reproduction [6] suggest that incorporating nutritional considerations into management decisions in these areas may benefit ruffed grouse populations [102,141]. It also underscores the importance of mast production for ruffed grouse in oak-hickory forests [34,141]. Tirpak and others [198] suggest that in mixed mesophytic forests, alternative (nonmast) foods allow for consistent survival over winter and high mast years increase reproduction. In oak-hickory forests, survival is generally lower because of limited food sources, and it increases in high mast years. In contrast, Thompson and Dessecker [192] state that in the Central Hardwoods region, occurrence of a specific plant species is not as important as vegetation structure. See Management Considerations for recommendations to improve availability of good-quality black-backed woodpecker forage.
Estimated reductions in foraging time due to the ease of collecting aspen have led to suggestions that ruffed grouse in northern regions with aspen have lower exposure to predators compared to ruffed grouse in other regions [98,192]. However, little data support this assertion (see Predation), and no information is available on the impacts of potentially lower energy requirements for foraging [98]. See Cover requirements: Foraging for information on specific components of foraging habitat.
Females are not territorial [24,156]. They occupy overlapping home ranges that vary from about 5 to 35 acres (2-14 ha). Home ranges are generally smallest during incubation and when raising a brood [156]. In central Missouri, average male ruffed grouse home range was greater in fall and winter than in spring and summer [194].
In addition to season, plant community and latitude influence home range size. In Minnesota, home ranges are generally larger in oak-hardwood forests in the southern portion of the ruffed grouse's range than in aspen (Populus tremuloides and/or P. grandidentata) forests (Epperson 1988, Thompson and Fritzell 1989, and Fearer 1999 cited in [156]). Data from 10 sites in the Appalachian region also indicate that ruffed grouse home range size declines with increasing latitude [206]. The average ruffed grouse home range size in Missouri was 168 acres (68 ha) in the spring and summer (Thompson and Fritzell 1989 cited in [156]). Average male ruffed grouse home range size in Minnesota in spring was 22 acres (8.9 ha) (Archibald 1975 cited in [156]). Home range sizes of females with broods were larger in Pennsylvania (146.8 acres (59.4 ha)) and Tennessee (106.7 acres (43.2 ha)) than in Minnesota (32 acres (12.9 ha)) (Godfrey 1975, Epperson 1988, Scott and others 1998 cited in [156]). Brood ranges in western North Carolina averaged 60 acres (24.3 ha) [103]. In oak-hickory forests of Rhode Island, ruffed grouse annual home ranges averaged 255 acres (103 ha) [43]. In various types of predominantly hardwood stands in Virginia, ruffed grouse home ranges averaged 82.3 acres (33.3 ha) [45].
Several other factors may influence home range size. For instance, on 10 Appalachian study sites, adult male home range size was about 2.5 times smaller than that of females or juvenile males, and male home range size was positively related to an index of population density. Home ranges were larger during successful breeding seasons than in unsuccessful seasons and decreased following closure of hunting [206]. Methological differences between studies also contribute to variability of home ranges estimates.
Although the importance of fire in creating ruffed grouse habitat is often described (see Habitat), data available as of 2011 on ruffed grouse's response to fire are not clear-cut. There are data suggesting ruffed grouse declined, had no response, or increased in the few years following fire (see Ruffed grouse populations and occurrence). In many cases, conclusions that can be drawn from data are limited due to small sample sizes, lack of controls, the anecdotal nature of the observations, variation due to population cycles, and/or other confounding factors. Data are also lacking on the long-term impacts of fire on ruffed grouse and on the influence of site and fire characteristics on ruffed grouse's response to fire. As noted by a literature review summarizing songbird responses to fire in southwestern ponderosa pine forests [47], there are several limitations to many studies addressing bird response to fire. Many studies focus on breeding communities and use composite statistics, such as species richness. Many are opportunistic, restricted in spatial or temporal scale, include confounding factors, and/or lack sufficient replication. Few compare demographic parameters of a given species between burned and unburned vegetation [47].
Ruffed grouse populations and occurrence: Although not statistically tested in many cases, short-term declines following fire have been observed throughout the ruffed grouse's range. In the 1st and 2nd years following a moderate to severe May wildland fire in a landscape comprised of quaking aspen, black spruce, bogs, and open land communities in Alberta, ruffed grouse populations in spring were about half of their prefire levels. Due to a lack of recruitment of new drummers, the density of drumming males on burned sites was about one-third of that on the unburned site by the 2nd postfire year [37]. In central Alberta, use of a recently burned stand comprised of thick quaking aspen saplings <1 inch (2.5 cm) DBH peaked in winter but never exceeded that expected based on availability [157]. In ponderosa pine-grand fir and ponderosa pine-Douglas-fir forests in the northern Rocky Mountains, ruffed grouse were observed at 3% of points in an unburned control with ladder fuels and small- to medium-diameter tree encroachment; 2% of points in sites burned by surface wildfires 1 year earlier; and were not observed at all on sites that were recently logged and/or burned to create the open understory structure typical of historical ponderosa pine woodlands [212]. In coniferous sites in western Montana, ruffed grouse relative abundance in the 3 years after mixed-severity wildfires was about 50% of the relative abundance in the 5 years before fire. In contrast, the mean relative abundance of ruffed grouse on control sites did not change substantially between the prefire and postfire periods. Statistical analysis of these differences could not be performed due to the few detections of ruffed grouse [176]. In scrub oak communities in Pennsylvania, ruffed grouse was apparently more abundant in unburned areas than in areas burned with prescribed fire 1 year previously [170]. In oak-hickory and beech-maple forest in Indiana in 1996, ruffed grouse occurred on unburned sites but not on sites burned in the spring of 1993 and 1995. The difference was not significant for ruffed grouse, but it was significant (P<0.013) for resident ground- or shrub-nesting birds [3]. In northwestern Minnesota, the average density of male ruffed grouse from 1963 to 1980 was 10/mile² in a control area and 6/mile² in an experimental area that had been burned in 1968, 1971, 1973, and 1975. Fires burned 59% to 90% of the study area, and by 1975 only 18% of the quaking aspen overstory remained. However, aspen suckers occurred in high densities in chokecherry (Prunus virginiana), pin cherry, willow, and red-osier dogwood (Cornus sericea subsp. sericea) shrublands, suggesting the clonal root network was intact [9].There are also data showing an ambiguous or no response of ruffed grouse to fire. In mountain big sagebrush (Artemisia tridentata subsp. vaseyana)-grassland communities in northwestern Wyoming, ruffed grouse were not observed during the year of burning on spring-burned, fall-burned, or unburned plots, and they were rare on both burned and unburned plots the year after burning [135]. In an Engelmann spruce-subalpine fir forest in northwestern Wyoming, ruffed grouse were observed about 3 years after a wildfire burned 648 acres (262 ha) from July to September. In the adjacent mature unburned forest, ruffed grouse were observed 2 years following fire, and they occurred at a density of 8.9 pairs/100 acres 3 years following fire. Ruffed grouse were also observed along the edges of the burned and unburned forest 2 years after the wildfire [145]. In western Montana, bird densities were recorded from 2 to 4 years following a July wildfire in a burned stand that was not cut, a burned stand that was cut, an adjacent unburned and uncut stand comprised of Douglas-fir, ponderosa pine, and western larch, and a control stand 5 miles (8 km) from the burn. Ruffed grouse only occurred in the unburned forest adjacent to the burn 2 years after fire and the burned and uncut stand 4 years after fire. In both cases they occurred at a density of 2 ruffed grouse/100 acres [77]. Although densities of ruffed grouse were lower on experimentally burned areas than in controls in northwestern Minnesota, population trends on the experimental and control areas were correlated (P<0.05). Declines just after the first fire may have been due to burning, but by the end of the study period population levels in both areas were low [9]. In northeastern Minnesota, ruffed grouse detections in June were similar on unburned sites and sites burned 4 years previously in a 15,000-acre (6,070 ha) May wildfire [139].
Positive responses have been observed within the first postfire years, primarily in aspen communities. Indices of ruffed grouse suggest greater abundance on burned than unburned aspen-scrub oak communities in Pennsylvania 1 year following prescribed fires [170]. Ruffed grouse abundance [62] and density [61] were positively related with acres burned in previous years in subboreal forests of Minnesota. Ruffed grouse density was significantly (P<0.001) associated with number of acres burned 1 (r =0.597) and 2 years (r =0.677) previously. Density was significantly (P<0.01) correlated with the number of fires 1 (r =0.536) and 2 years (r =0.498) previously [61]. More generally, ruffed grouse population peaks occurred about 4 and 15 years following major fire years the early 1900s [62]. The creation of young aspen stands following fire is an often mentioned benefit of fire for ruffed grouse (see Habitat).
Ruffed grouse use of burned sites has been observed in many communities and at varying times since fire. Sharp [169] noted ruffed grouse dusting in early May and brood use in summer on sites burned in early spring in oak-hickory communities of Pennsylvania. Two years following a mid-May wildfire in northeastern Minnesota, ruffed grouse occurred in an aspen community at a density of 1 male/ 29.5 acres [10]. Ruffed grouse occurred on 4 of 33 northern Rocky Mountain coniferous forest sites that had burned in a stand-replacement fire 1 or 2 years previously [95]. Percent of points where ruffed grouse were detected was 3% to 4% on sites burned in stand-replacement fires compared to 12% in cottonwood/quaking aspen forests in northern Idaho and western Montana [96]. In northeastern Minnesota, ruffed grouse were uncommon 2 and 3 years following a 15,000-acre (6,070 ha) May wildfire, but they were common on both burned and unburned areas 4 years after the fire [139]. In a jack pine-black spruce forest in northeastern Minnesota, ruffed grouse were observed 3 and 22 years following a 3,380-acre (1,368 ha) autumn wildfire, although they were not detected before the fire or at postfire years 1, 7, 19, 23, or 30 [71]. In a pitch pine community in Massachusetts, ruffed grouse occurred in stands burned under prescription 2 years previously in spring, summer, or fall. Ruffed grouse were also present in regenerating stands burned 10 years previously in summer or winter, and there was a ruffed grouse territory on a site that was spring-burned 30 years previously [122]. Ruffed grouse occurred on a Vancouver Island site that had been logged and burned 20 years earlier [106]. In the Engelmann Spruce-Subalpine fir dry, cool biogeoclimatic zone of the northern Rockies in eastern British Columbia, ruffed grouse were observed in stands that were burned 27 to 45 years previously. On average, 2 individuals/km² were detected in burns of this age [187]. In Yellowstone and Grand Teton National Parks in Wyoming, ruffed grouse were common in lodgepole pine forests 30 to 50 years and 50 to 100 years after severe fire. Forty-three years following severe fire, they occurred at a density of 2 pairs/100 acres in a dense lodgepole pine stand with openings. Ruffed grouse were present in a shrub-young forest 25 years following severe fire but did not occur in another shrub-young forest that burned 29 years previously. Ruffed grouse were not observed in the first 3 years following a moderate fire or in the first 17 years following severe fires [190]. In a meta-analysis of data from boreal forests, ruffed grouse were common in 11- to 30-year old burns, in aspen and mixedwood stands of aspen, spruce, and/or birch 76 to 125 years after fire, and in mixed-wood stands more than 125 years after fire. They were uncommon in burns ≤10 years old that had live trees remaining on the site, in forests 31 to 75 years after fire, and in aspen stands 125 years after fire. Ruffed grouse were rare in white spruce stands over 125 years following fire and in burns ≤10 years old that had no live trees remaining [162].
Fires may benefit ruffed grouse by controlling parasites. Control of insect parasites, such as wood ticks, and disease were considered benefits of fire for grouse in Wisconsin [57]. Parasites of blue grouse (Dendragapus spp.) including Disoharynx nematodes, for which ruffed grouse is a host, have been shown to increase with time since fire [8].
Habitat: Since early-successional and disturbance-dependent forests often provide quality ruffed grouse habitat (see Stand ages and Cover requirements), fire may increase the quantity and/or quality of ruffed grouse habitat [25,28,60,70,79,94,105,159,202,208]. Gullion [60] notes that the hardwood forests that provide the best ruffed grouse habitat are maintained by fire and that fire discourages the establishment of spruce, fir, and other late-successional conifers that may provide less favorable habitat. In Alaska, ruffed grouse occur in deciduous forests, which tend to establish in burned areas before conifers do [202]. Fires in Wisconsin eliminated dense mats of dead grasses, sedges, shrubs, sticks, and other debris. Removal of this "rough" benefits many grouse species [57]. In the southern Appalachians, fire may maintain oak-hickory forests and prevent succession to red maple or other shade-tolerant forest types [204]. It is commonly suggested that fire exclusion has resulted in ruffed grouse habitat degradation and declines in habitat availability [80,136,156].
Fires tend to increase interspersion of habitats, which is likely to benefit ruffed grouse [57,60,70,107]. In Wisconsin, the variation in stand density, species composition, and spatial arrangement of these stands due to numerous fires was an important factor in producing high ruffed grouse yields [57]. In western Virginia, patchy prescribed fires created both foraging opportunities and cover due to unburned pockets occurring within the burned area [107]. Gullion [60] notes that mixed-severity fire results in interspersion of stand age classes and species, from old, fire-intolerant species in areas missed by a fire to areas where forest cover has been removed and pioneering species establish. In a review, Crawford [24] suggests fire can be used to inexpensively increase edge. See Landscape-level requirements for details of habitat interspersion's contribution to ruffed grouse habitat quality.
In some cases, ruffed grouse habitat availability and quality may be negatively impacted by fire. Fires in areas being used by ruffed grouse may reduce habitat availability, depending on fire severity [57], uniformity, season, and size. Ruffed grouse were common on a boreal forest site in Alberta that had been clearcut 25 years previously, but they were uncommon on a similar site that had burned 25 years previously. A lack of live residual trees, more dead wood, and a less developed shrub layer on the burned site may have contributed to this trend [73].
Fire impacts different types of ruffed grouse habitat in different ways. It is likely to have the most immediate benefits to ruffed grouse brooding and foraging habitats. Nesting cover may be improved by reducing dense underbrush and preserving the relatively park-like conditions that characterize many nesting areas [60]. Since coarse woody debris may increase the quality of breeding and brooding habitat, fire that produces more coarse woody debris than it consumes could benefit ruffed grouse. However, excessive amounts may limit movement of chicks and inhibit the growth of food plants [204]. Fire can produce habitat with dense understory and open ground layers that are used for cover. However, not all fires in communities occupied by ruffed grouse result in suitable ruffed grouse cover. For instance, fires may not be severe enough to open the canopy sufficiently to promote adequate aspen regeneration [67]. Short-term impacts may be negative. In a quaking aspen-balsam poplar/thinleaf alder (Alnus incana subsp. tenuifolia)-red alder community, a May wildfire reduced thinleaf alder cover <3 feet (1 m) tall on drumming sites from an average of 28.7% cover along a transect line before fire to 2.9% cover after fire [37]. See the FEIS review of gray alder (A. incana) for more information on the impact of this fire on the alder component of ruffed grouse cover. Winter roosting habitat may also be affected by burning. Fire can result in fewer tree roosts and alter snow characteristics such as depth, duration, and crusting [127]. For example, large openings may allow for greater snow accumulation [109]. Little information is available on the influence of fire and site characteristics on the quality of ruffed grouse habitat or the time needed for ruffed grouse habitat to develop after fire.
In aspen communities, moderate-severity fires that kill aboveground stems and eliminate litter but do not damage roots generally result in dense suckers (see Cover requirements) that provide ruffed grouse habitat [7,67]. Gullion [67] suggests that burning in spring may regenerate some aspen stands but is unlikely to succeed in older stands most in need of regeneration. Generally, this is due to a lack of fuel, resulting in fires that are not severe enough to initiate suckering [67]. In 4 stands in Minnesota, sugar maple reproduction was eliminated and aspen regeneration was stimulated by burning, but the reduction in overstory hardwoods was inadequate to produce ruffed grouse cover. On 2 other sites, fire maintained ruffed grouse habitat by promoting aspen sprouting and reducing reproduction of shade-tolerant species. Fire was most effective in treating young aspen stands. These areas had more fuel and smaller trees with thinner bark than stands with an average tree diameter exceeding 5 inches (13 cm). Above this size, the authors indicate that harvest will likely be required to produce ruffed grouse habitat [159]. Multiple fires in young aspen stands would likely cause detrimental impacts to ruffed grouse habitat [17]. Prescriptions for aspen that would provide a moderate rate of spread are provided by Sando [159]. See the FEIS reviews of quaking aspen and bigtooth aspen for detailed information on their responses to fire.
Brooding: Fire may create and improve ruffed grouse brooding habitat in the short term. In oak-hickory forests of West Virginia, escape cover ratings for ruffed grouse broods were significantly (P<0.05) higher on sites burned a few months previously than on sites burned over 2 years ago or untreated controls [153]. On a North Carolina study site, within 2 growing seasons after a March prescribed fire in oak-hickory forest, a diverse herbaceous community had developed that several broods used almost exclusively [141]. In oak-hickory forests of West Virginia, prescribed fire following clearcutting increased the value of the clearcuts as brood habitat. The abundance of some early-successional species increased, plant and insect forage increased (see Foraging below), and shade-tolerant species such as red maple decreased. Availability of insects was about 38% greater on the burned areas during the 2nd growing season after the fire than on control areas. This difference was significant for small bugs (Hemiptera) and beetles (Coleoptera) [204]. Increases in herbaceous cover (Bowles and others 2007 and Elliott and others 1999 cited in [103]) following fire suggest fire could improve brood habitat [103]. Haulton and others [78] suggest that prescribed burning and stand thinning may be more appropriate in creating brood habitat in the southern Appalachians than in more northern regions, because ground cover seems more important to brood habitat than stem density in the southern portions of the ruffed grouse's range (see Cover requirements: Brooding).
In oak-hickory forests of West Virginia, prescribed fire following clearcutting reduced the density of small-diameter (<1 inch (2.5 cm)) coarse woody debris by about 50%. Given the potential for excess logging slash to negatively impact broods (see Coarse woody debris), this reduction was considered an improvement to brood habitat [204].
Foraging: In some situations, ruffed grouse consume more vegetation and insects in burned areas than unburned areas. In oak-hickory forests of West Virginia, feeding rates of human-imprinted ruffed grouse chicks were significantly higher on burned sites. Chicks fed on invertebrates at a significantly greater rate on sites burned a few months previously than on sites burned 2 years before or on untreated sites. Vegetation feeding rate was significantly greater on a site burned 2 years previously than on sites burned a few months before or untreated controls (P<0.05). Feeding rates on thinned and burned sites were similar to those on sites that were only burned [153]. Ruffed grouse were observed eating new sprouts of willow, hazelnut, and birch 1 year after a 61,800-acre (25,000 ha) August fire in old-growth red and eastern white pine communities of Quetico Provincial Park in Ontario [126]. Significantly more arthropods were observed in ruffed grouse droppings collected from open, herbaceous old fields of New York that were burned in late April and early May than in unburned areas. Given the lack of insects in droppings collected from drumming logs and males' tendency to stay near drumming logs at this time of year, it is suspected that females were consuming insects in the recent burns [44].
Fire may increase the abundance of ruffed grouse food plants. Increases in fruit production in the years following fire [57,169] and greater abundance of groundlayer vegetation such as grasses, sedges, and legumes (Fabaceae) have been reported following fire in oak-hickory communities of Pennsylvania [169] and in Wisconsin [57] and Minnesota [60]. Fire may also increase acorn production [57] and prevent succession from early-seral stages that include oaks to late-successional stages with shade tolerant species that do not provide acorns, such as red maple [204]. A review notes that in northern Idaho, fire maintains seral shrubfields that produce berries eaten by ruffed grouse [175]. In oak-hickory communities of Pennsylvania, early spring burning promoted establishment of some food plants including blackberries, sumacs, and grapes. Fire may also promote aspen establishment where there is a seed source. Common gypsyweed (Veronica officinalis) and woodland violets (Viola spp.) germinated in burned areas in spring, providing important food for ruffed grouse chicks in summer. Tick trefoils were abundant in fertile woodlands following fire. In areas that were harvested and not burned, the species present before the fire came back "vigorously", but unlike in the burned areas, new species did not establish. Fire on this site also limited a leaf spot fungus that was killing white edge sedge (Carex debilis), a ruffed grouse food [169]. In West Virginia, prescribed burning following clearcutting in oak-hickory forests increased some early-successional plants including common mullein (Verbascum thapsus, P=0.0946) and black locust (P=0.0012) [204]. In Wisconsin, fruit production in trees such as cherries and serviceberries (Amelanchier spp.) increased several years following fire, and fire promoted production of new shoots that are a preferred ruffed grouse food [57]. In contrast, in loblolly pine (Pinus taeda)/legume stands more than 20 years old in the South Carolina Piedmont, prescribed fires of moderate severity during the spring or summer did not significantly change the abundance or frequency of legume plants [26].
A review notes that several factors influence ruffed grouse food production following fire [97]. A potential increase in food availability following fire is generally assumed due to increases in light [57,60], exposed mineral soil [169,204], and availability of nutrients [60]. Whitaker and others [204] did not observe increases in soft mast the 2nd year following fire and suggest the dry conditions occurring at the time of their study may have delayed the expected increase in berry production on burned sites.
Fire may also improve the quality of ruffed grouse food plants. Since a burned quaking aspen stand was rarely used for winter roosting, an increase in the use of this stand in winter compared to other seasons may have been due to the high quality of food in the burn [157]. Gullion [62] suggested that fire-damaged aspen may provide better nutrition than unburned individuals. Burning increased protein and phosphorus (P<0.01) levels and decreased fat (P<0.01) and crude fiber (P<0.05) in mountain-laurel leaves [191], which were an important winter ruffed grouse food source on sites in eastern Tennessee and western North Carolina [178]. Fire may increase the nutrition provided by foods on a site by accelerating nutrient cycling [60]. Grange [57] notes the fertilizing effects of nutrients in ash and their potential to increase plant palatability.
Burning may increase the availability of ruffed grouse's insect prey. Based on observations following small prescribed fires in late April and early May in open, herbaceous old fields in New York, Euler and Thompson [44] suggest that ruffed grouse's increased foraging on insects in burned areas may be due to increased visibility of insects due to decreased cover and increased insect activity, and/or earlier insect emergence due to increased temperatures in burned areas [44]. Gullion [60] also suggested that increased temperatures in burned areas may increase insect availability.
Landscape-level characteristics contribute substantially to ruffed grouse habitat quality. The size of forested patches, their relation to other forested patches, and the amount of interspersion and edge within forested patches all influence ruffed grouse habitat quality.
Ruffed grouse are associated with large forested areas, typically a minimum of 40 to 250 acres (16-100 ha). Large blocks of aspen and oak forest provide better habitat than small patches [156]. The habitat suitability index developed for the Central Hardwoods region included a forest area requirement, with habitat suitability increasing in forest patches of 250 to 987 acres (100-399 ha) and peaking in patches of 988 acres (400 ha) or more [151]. In fragmented aspen woodlands in north-central North Dakota, ruffed grouse occurrence increased with the size of aspen patches (P<0.01). The estimated probability of ruffed grouse occurrence was 50% in aspen groves of 250 to 494 acres (100-200 ha) and 76% in groves of 2,470 acres (1,000 ha) or larger. No ruffed grouse were observed in aspen groves of 25 acres (10 ha) or less [58]. In Douglas-fir forests in northwestern California, ruffed grouse were positively associated with stand area (P<0.1), with patches less than 49 acres (20 ha) having low frequency and relative abundance of ruffed grouse. Ruffed grouse frequency increased to 20% in stands 50 to 250 acres (21-100 ha) and was 40% in stands larger than 250 acres [155]. In boreal forests of Alberta, evidence of ruffed grouse breeding occurred in riparian buffer strips that were 660 feet (200 m) wide but not in narrower buffer strips [74]. In contrast, in boreal forests of north-central Saskatchewan, there were no significant relationships between ruffed grouse occurrence and fragment size [86]. Ruffed grouse released into northern Missouri used open land more than 5 times what would be expected based on availability and old fields about 2 to 3 times what would be expected [111]. A minimum patch size of 25 to 50 acres (10-20 ha) is commonly recommended [27,32] (see Habitat management considerations).
Contiguous blocks of aspen or oak forest may provide better habitat than isolated and/or fragmented forests surrounded by agricultural fields [156], although evidence is sparse regarding this generalization. According to a ruffed grouse Habitat management guide for landowners, the minimum patch size for successful management of ruffed grouse varies with surrounding habitat type, with ruffed grouse more likely to occupy connected patches than isolated patches [32]. In Douglas-fir forests of northwestern California, relative abundance of ruffed grouse appeared to decrease with increasing high-contrast edge on the stand's perimeter (0.2 ruffed grouse/36 counts in stands with <10% high-contrast edge vs. about 0 in stands with >75% high-contrast edge, not stastically significant) [155]. In contrast, in southern boreal forests dominated by white spruce and quaking aspen in north-central Saskatchewan, ruffed grouse were randomly distributed between contiguous and fragmented habitats [86].
Ruffed grouse show both positive and negative relationships to amount of edge. This may reflect differences in study design such as scale, the types of edges investigated, and/or differences in ruffed grouse habitat requirements across their range. For instance, in Pennsylvania, brood survival increased with increasing proximity to edge at the site scale but decreased with increasing road density at the landscape scale (See Cover requirements: Brooding for details) [197]. In predominantly hardwood stands in Virginia, landscapes with lots of high-contrast edge were selected by ruffed grouse (P<0.01) [46] and were significantly (P<0.01) associated with smaller ruffed grouse home ranges and decreased movement [45]. In a Pennsylvania landscape comprised of bigtooth aspen, quaking aspen, pitch pine, several oaks, and red maple (Acer rubrum), breeding males were only observed in areas that had been clearcut 3 times. The 3rd cut increased the length of edge between stand age classes of about 1, 6, and 11 years old by 75% [209]. In central Pennsylvania, random sites were significantly farther (P≤0.006) from edges and openings than sites where females with broods were observed [166]. Ruffed grouse abundance and frequency in Douglas-fir forests of northwestern California were positively associated with areas adjacent to hardwood stands (P<0.01), but they were not significantly impacted by either the amount of total edge in 2,500-acre (1,000 ha) blocks or the amount of edge in the plot [155]. In contrast, in southern Ontario, ruffed grouse were positively associated (P<0.1) with the amount of forest more than 330 feet (100 m) from an edge [4]. Ruffed grouse in northern Minnesota exhibited greater survival in pure hardwood and pure coniferous forest stands than in similar stands with edge (P<0.025) [60,61].
It has been suggested that ruffed grouse prefer edges in areas of low-quality habitat ([64], Dessecker and McAuley 2001 cited in [31]). Gullion [64] elaborates by explaining that in aspen habitats, ruffed grouse obtain cover and food in the same stand, well away from edges. He states that only in poor-quality areas is there a need for edges comprised of a dense shrub layer or young tree layer next to a mature overstory that provides food [64]. Based on the influence of landscape characteristics on ruffed grouse home ranges in Virginia, Fearer and Stauffer [45] suggest that associating edge with poor-quality habitat may be appropriate in aspen, but edge may be a necessary aspect of ruffed grouse habitat in eastern and southeastern portions of the ruffed grouse's range. Since regeneration cuts may not meet ruffed grouse foraging requirements, adjacent mature stands are required to supply adequate nutrition [45]. The edges associated with interspersion of different ruffed grouse habitats likely benefit ruffed grouse.
Interspersion of habitats within large forested areas is necessary to meet the year-round requirements of ruffed grouse. Proximity of cover near foraging habitat [32,144,151,156], nesting habitat near brood habitat [192], and young forest near mature forest [24,144] are often mentioned as important for ruffed grouse. Proximity of drumming and nesting habitat may be important [215] in areas where they differ [66,205]. In predominantly hardwood stands in Virginia, ruffed grouse selected landscapes with highly interspersed preferred habitats, landscapes with small (1.2-12 acre (0.5-5 ha)), roughly square patches of differing ruffed grouse habitats (P<0.01) [46]. There was a positive (P=0.008) association between the area of habitat patches away from edge and home range size, with smaller patches resulting in smaller home ranges [45]. The habitat suitability index developed for the Central Hardwoods region includes interspersion of early-successional forest and acorn-producing forest [151]. In Idaho, the differences in microhabitat characteristics used by different groups of ruffed grouse (see Cover requirements below) led the authors to conclude that several conditions must exist for a quaking aspen stand to provide year-round ruffed grouse habitat [180]. In Minnesota, ruffed grouse occurred at higher densities where wetlands, conifer, mixed conifer-aspen, and hardwood forests were evenly distributed compared to areas where one of the habitats dominated. This trend may be caused by differing requirements at different life history stages or variable weather necessitating differing types of cover [215]. In contrast, in southwestern Virginia, areas with a greater variety of plant communities support fewer ruffed grouse, possibly because increasing the variety of plant communities eventually increases the amount of vegetation unfavorable for ruffed grouse [45].
Based on the need for interspersed habitats, several researchers have recommended small treatment areas. Gullion and others [24,63,66] recommended that aspen clearcuts be no more than 25 acres (10 ha), so that no one age class comprises too large an area. Clearings for brood foraging habitat are typically about 0.25 to 1 acre (0.1-0.4 ha) (Sharp 1963 cited in [156]). Based on operational considerations, Jones and Harper [102] recommended cuttings that vary in size from 2 to 40 acres (0.8-16 ha) and noted that presence of early-successional habitat was more important than size of clearcuts. See Habitat management considerations for more detail regarding treatment sizes.
Federal legal status:
No special status
Other status: Information on state- and province-level protection status of animals in the United States and Canada is available at NatureServe, although recent changes in status may not be included.
Population trends: In a comprehensive review, Rusch and others [156] suggest ruffed grouse populations are likely stable in Canada and the western United States and declining in the eastern United States. Ruffed grouse populations in the Appalachians were likely declining from 1996 to 2002 [34] and were declining in Ohio from 1982 to 1998 [189]. Tirpak and others [198] determined ruffed grouse on all Appalachian sites investigated were declining. According to reviews, survey data suggest declines in Indiana and Ohio [31], and hunter flush rates indicate long-term declines in Ohio, Tennessee, and Virginia and inconsistent trends in West Virginia and North Carolina [192]. It has been suggested that population declines are due to lack of early-successional habitats in eastern forests, but population cycling complicates the interpretation of this information [31].
Habitat The major goal of ruffed grouse Habitat management is providing a continuous [31] and adequate supply of interspersed successional stages of sufficient quality to meet ruffed grouse's various habitat requirements [24,32,34]. This typically involves creation of early-successional habitat [24,32], which is done by cutting, grazing, and/or burning (see Fire Management Considerations) [24]. Improving or enlarging foraging areas may be important, especially in the Appalachian region. Seeding roads with clovers and small forbs, eradicating nonnative perennial cool-season grasses, and enhancing acorn production may assist in achieving this goal [34]. Encouraging consistent production of soft fruits and herbaceous leaves and increasing abundance of soft and hard mast species may increase winter and spring ruffed grouse carrying capacity [140]. Tirpak and others [199] provide recommendations for nesting habitat that include retaining stands with basal areas of >25 m²/ha near early-successional stands. In 2-age stands with residual basal areas <25 m²/ha, a minimum of 20% cover of large-diameter (≥6 inches (15 cm)) coarse woody debris is recommended for nesting areas [199]. However, in aspen stands, coarse woody debris may provide better cover for predators than for ruffed grouse [63]. Logging roads near nesting areas provide brooding habitat and are even more attractive to ruffed grouse when seeded [199,205]. These foraging areas may help buffer the impacts of years with poor mast production. Increasing insect production and ground cover in bottomlands was also recommended to provide brood habitat [205]. In oak-hickory forests of Pennsylvania, small clearcuts (0.25-1 acre (0.1-0.4 ha)) resulted in the creation of brood habitat that lasted about 7 years [168].
Management techniques used vary with plant community and other site factors. For instance, recommended forest rotation lengths vary from about 40 years in Douglas-fir stands [158] and 40 to 60 years in aspen [27,32,63] to more than 80 years in forests of the Central Hardwoods [192] and about 50 to 150 years in mixed and deciduous forests [24]. More rapidly maturing species are managed on shorter rotations, allowing for more early-successional habitat on the landscape at any one time [31]. Rotations in northern hardwoods can be as short as those in aspen, and decreasing stand size allows for longer rotations when necessary [208]. Clearcutting is nearly universally recommended for creating ruffed grouse cover in aspen [63,66], northern hardwood [141,208], mixed-mesophytic [141], and Central Hardwood communities [192]. Gullion [63] recommends that less than 10% canopy cover remain following harvesting in aspen to ensure adequate aspen regeneration for ruffed grouse. In aspen/scrub oak and mixed-oak communities in central Pennsylvania, short-rotation clearcutting of 2.5-acre (1 ha) patches created brood habitat [166]. Clearcuts may create breeding [115,134] and summer cover for males in oak forests. Males selected (P<0.001) an area managed by clearcutting 1-acre (0.4 ha) patches in an oak-hickory forest of Pennsylvania in spring and summer [134]. Ruffed grouse density in the managed oak-hickory community was greater than in managed aspen stands (McDonald and others 1994 cited in [134]). In oak-hickory forests, alternative timber harvesting techniques have been suggested, since clearcutting may reduce food resources (see next paragraph). It may take many years after cutting for species such as oaks and beech to produce hard mast [141,205]. In conifer stands, wider spacing of trees than is common in hardwood stands is recommended to encourage a dense understory [213]. Uneven-aged techniques are typically not suitable for creating habitat for ruffed grouse or other species that depend on early-successional conditions [192].
Selective harvesting may be a useful technique for ruffed grouse Habitat management in some circumstances. In oak-hickory forests, group selections may improve brood habitat and, when positioned appropriately, provide travel corridors. Thinning between groups may also improve connectivity [102]. Use of irregular shelterwood and 2-age techniques also benefit ruffed grouse in oak-hickory forests. By opening the forest, shelterwood cuts increase herbaceous ground cover, soft mast production, and (in later stages) midstory stem densities. Retaining trees that produce hard mast allows for provision of acorns, other food sources, and cover in the same stand [141]. For the Appalachian region, Devers and others [34] recommend silvicultural techniques that improve acorn production. They suggested use of multiple techniques, including clearcuts that create early-successional cover and shelterwood harvests that leave hard mast reserves for foraging [34]. On a North Carolina study site, ruffed grouse selected shelterwood and 2-aged stands in fall and spring. Use of these areas began 3 years following treatment and continued through the remaining 3 years of the study [102]. In oak-hickory communities of the southern Appalachians, basal areas of less than 16m²/ha were suggested to encourage development of the shrub-seedling-herb layers [140]. Use of shelterwood harvests in the Central Hardwoods region was more limited, since they typically do not remove enough overstory to produce dense understory cover. Crop release cutting is not recommended in the Central Hardwoods region in stands providing good habitat [192]. In contrast, if group selections are large and clustered, with no more than 20 ft²/acre retained in clumps of several large trees, the stand may develop the high stem densities required by ruffed grouse. Selection cutting may also be useful in riparian areas of this region [192]. As little as 10% canopy cover or basal areas of 2.5 to 3.7 m²/ha remaining may limit aspen regeneration ([63], Perala 1977 cited in [31]).
Size and arrangement of recommended treatments are based on the landscape-level habitat requirements of ruffed grouse. In Central Hardwoods forests, cuts of more than 10 acres (4 ha) are recommended because they may provide better ruffed grouse cover than many small harvests scattered in a landscape dominated by mature forests [192]. Jones and Harper [102] recommend clearcuts that vary from 2 to 40 acres (0.8-16 ha) in the Appalachians. They suggest harvesting at midslope to provide corridors between ridgetop drumming and roost cover and the diverse food sources in bottomlands. Harvesting on mid- and lower slopes in the southern Appalachians was recommended to improve connectivity of the ridgetops used by males and areas used by females in the breeding season [164]. In New Hampshire, small clearcuts were placed near areas with well-developed herbaceous cover and winter food sources, such as areas with paper birch, black cherry, or apple trees [208]. In aspen forest in Minnesota [63,66], the West [27], and in general [32], management units of about 40 to 50 acres (16-20 ha) were recommended, with 10 acres (4 ha) harvested every 10 to 15 years. This would maintain 4 age classes within about 300 feet (91 m) of each other [63,66]. Cuts of 25 to 50 acres (10 to 20 ha) were recommended for sites in western Washington [158].
Timber harvesting may have may have some short-term negative effects on ruffed grouse. Ruffed grouse densities may decline immediately following cutting [61]. Timber harvest may disturb nesting and result in loss of nest sites, winter cover [144], and feeding areas [61,144]. In either harvested or burned boreal forests, the salvaged-logged stands had the lowest ruffed grouse habitat quality [200]. However, in boreal forests of western Quebec, ruffed grouse showed no short-term response (P>0.1) to harvesting in mixed and deciduous forests. Machinery access was limited to reduce impacts on vegetation regeneration [147].
Grazing in aspen may also benefit ruffed grouse [39] by creating open areas and maintaining brushy stages [24]. However, heavy grazing [24,144] and grazing within about 2 years of clearcutting [144] are detrimental to ruffed grouse.
Other recommendations for managing ruffed grouse habitat include protecting shrub thickets during harvesting [24,192]; maintaining herbaceous openings near dense cover [192,208], including areas of conifers for winter cover [144,192]; and, west of the Cascade Range in Washington, protecting riparian habitats for at least 330 feet (100 m) on either side of streams [158]. In northern Minnesota, ruffed grouse apparently declined in riparian buffer zones adjacent to harvest blocks compared to controls [75]. In New Hampshire, maintaining openings of about 0.5 to 0.75 acre (0.1-0.3 ha) for every 10 acres (4 ha) of closed forests was recommended [208].
Much more detail regarding managing habitat for ruffed grouse is provided in several sources. For instance, information on spatial and temporal arrangement of harvests in aspen [32,64], harvest strategies for other communities [32], and creation of drumming logs [64] is available. For information on effects of zoning strategies on amount of ruffed grouse habitat, see Zoller and others [217]. Another Zollner and others [218] article addresses impacts of various harvest strategies on many, sometimes conflicting, objectives including creating ruffed grouse habitat [218]. Rickers and others [150] described a GIS-based method for projecting extent of future ruffed grouse habitat based on potential management actions. For information about sensitivity of population growth rate to various ruffed grouse survival and reproductive parameters and other population management-related information, see Tirpak and others [198].Hunting pressure is apparently low enough in most areas that it does not impact ruffed grouse populations [22,24,34,101,156]. Mortality due to hunting was 11% in North Carolina [101], 12% in the Appalachian region [34], 29% in northwestern Wisconsin [5], and 12% to 35% on 2 sites in Michigan over 5 years [22]. Hunting during population cycle lows [22] and the resulting high harvests during long hunting seasons and high bag limits may have negative impacts on ruffed grouse populations [5,110]. Hunting may alter ruffed grouse habitat selection [205].
Population cycles: In Canada, Alaska, and the Great Lakes states, ruffed grouse populations typically exhibit cycles of increases and declines [104,156], with lows often 80% of peak population levels (Keith 1963 cited in [24]) and cycles repeating about every 10 years [24,104,156]. Population cycles do not generally occur in other portions of the ruffed grouse's range [156,192], and not all northern populations exhibit cycles (Graham and Hunt 1958, Keith 1963, and Theberge and Gauthier 1982 cited in [24]). Reproductive failure has been observed before a ruffed grouse population decline [61], and population lows have often been associated with decreased survival ([5,104], Rusch and others 1978 and Ransom 1965 cited in [116]).
Predation [5,104] is a commonly suggested driver of ruffed grouse population cycles. Ruffed grouse populations may decline due to increased avian predation following snowshoe hare (Lepus americanus) population declines ([5], Lauten 1995 cited in [156]). During a ruffed grouse population decline in northwestern Wisconsin, juvenile survival rates during autumn and winter and adult survival during winter declined about 50%. Avian predation rates increased from less than 5% in 1989 to over 30% in the winter of 1992. This increase coincided with increased Christmas bird counts and migration counts of northern goshawks and, to a lesser extent, great horned owls. Ruffed grouse nest success did not vary significantly between years [5]. Ruffed grouse survival was negatively correlated with winter predation in Alberta (P<0.01, r = -0.88), and the timing of ruffed grouse population decline matched immigration of northern goshawks into Minnesota [104]. Although not reported in the literature, mammalian predation of ruffed grouse may also increase when small mammalian prey decline. American martens had greater amounts of grouse, including ruffed grouse, in their diets when small mammalian prey was relatively rare [171].
Weather has also been suggested as a driver of ruffed grouse population cycles. Detrimental winter conditions in northern Minnesota resulted in low reproductive output by ruffed grouse the following spring [61]. Since there were too few recruits to replace ruffed grouse lost during the winter, the population declined. Based on ruffed grouse census data from 1927 to 1955 in the same area, an increase of 1 °F in maximum temperature in early July was associated with an increase in ruffed grouse density of 0.15 ruffed grouse/mile² the next April, while a 1 °F increase in maximum temperature in mid-February was associated with a decrease of 0.1 ruffed grouse/mile² the next April [117]. Winter predation can alter predicted effects of temperature. For instance, in 1961 high predation rates during winter undermined a potential increase from productive nesting the previous season [61].
Amount of continuous habitat, vegetative composition, and habitat manipulation have been suggested as reasons for a lack of population cycling in some boreal and mixed-forest communities in the northern portion of the ruffed grouse's range (Graham and Hunt 1958 and Keith 1963 cited in [24]). Habitat availability associated with postfire plant succession has also been suggested as influencing population levels (see Indirect Fire Effects: Habitat). Lack of habitat or habitat occurring in isolated patches may explain why some snowshoe hare populations do not exhibit cycles (Buehler and Keith 1982 cited in [104]). A 1980 review by Larsen [116] provides more detail on how weather, predation, and fire may affect ruffed grouse population cycles.
More recent research suggests ruffed grouse population cycles are influenced by multiple factors including forage quality, weather patterns that affect snow roost availability, and predator abundance. The lack of strong associations between ruffed grouse indices and winter weather and/or northern goshawk indices suggests that factors influencing population cycles are complex and largely unknown [216].
Reproduction: Drumming defines territories and makes females aware of males' presence, so females visit male territories. They may visit more than one male territory, and males may fertilize more than one female. Male ruffed grouse produce a drumming sound by spreading their wings, rotating them forward, and then moving them back quickly. The air rushing into the momentary vacuum created produces the drumming sound. Males beat their wings up to 50 times in the 8 to 11 seconds it takes to complete a drumming sequence. Males do not assist with nest construction, incubation, or brood rearing [156]. Other breeding behaviors, vocalizations, and time budgets during the breeding season and other times of year are discussed by Rusch and others [156].
Reproductive timing: Drumming peaks in spring, typically early April in the southern portion of ruffed grouse range and late April or early May in the northern portion. Drumming typically occurs half an hour before to several hours after sunrise and briefly before sunset. During the spring peak in drumming, males may drum in the late morning and/or afternoon. Drumming is infrequent in midsummer, increases in fall, and is sporadic in winter.
Breeding occurs in spring and coincides with increased drumming. Mating generally occurs in April, from early April in Georgia to late April in Minnesota, northern Wisconsin, Manitoba, and Alberta (Gullion 1984, Yoder personal communication, and Rusch personal observation cited in [156]). Females generally nest as yearlings [24,156].
Following mating, females take 3 to 7 days to build nests, which are bowl-like depressions on the ground that are lined with vegetation. In Minnesota, egg laying begins as early as 24 April and continues for 14 to 17 days (Maxson 1977 cited in [156]). Incubation begins after laying of the last egg and typically lasts 23 or 24 days [156]. In the Appalachian region, the average start of incubation was 1 May, ranging from 27 April to 8 May, with adult females initiating incubation an average of 3.5 days earlier than immature females [34]. During this period females spend 96% of their time on the nest (Maxson 1989 cited in [156]).
Median hatching dates of 1st nests were from 1 to 11 June in the northern portion of the range, 22 May in southeast Ohio and northeast Iowa, and 25 May in the southern Appalachians (Small and others 1996 cited in [156]). First-nest attempts on 2 sites and in 2 years in West Virginia ranged from 18 to 29 May [36]. Second-nest attempts are typically started in May (Archibald 1976 and Maxson 1977 cited in [24]). Median hatching date in northern Lower Michigan was 10 June for 1st nests and 1 July for renests [119]. Median hatching dates of 2nd nesting attempts in the southern Appalachians ranged from 26 June to 4 July.
Chicks are precocial. Within 2 to 3 hours of hatching they walk, feed themselves, and hide from predators. The brood leaves the nest within 24 hours of hatching, and chicks fly short distances within 5 to 7 days. Females brood chicks at night and during inclement weather for 3 weeks following hatching. During this period females also defend chicks against predators. Females stay with their broods until late August to early September, when the 12- to 15-week old chicks begin to disperse [156].
Reproductive output: Ruffed grouse raise one brood per season. If the first nest is lost early in the spring, they may renest [156]. In the southern Appalachians, 82% of hens nested (Haulton 1999 cited in [156]). In the Appalachian region, an average of 96% of females attempted to nest and 23% renested [34]. In West Virginia, 98% of females attempted to nest but only 1 of 41 females renested [36]. In the central and southern Appalachians, the ratio of first nests to renests was 18:1 [198]. In northwestern Wisconsin, all females attempted to nest and 60% renested [5]. Renesting rates were 56% in Wisconsin (Small and others 1996 cited in [156]), 8% in the southern Appalachians (Haulton 1999 cited in [156]), and 67% in Michigan, with 48% of yearlings and 100% of adult hens renesting (Larson 1998 cited in [156]). In the Appalachian region, modeling indicated that forest association influenced renest rate (see Plant associations used as habitat for details), and renesting was negatively associated with the average monthly minimum temperature in winter [34].
Reviews report average clutch sizes of 7 [156] and 11.5 eggs [24] and ranges of 4 to 19 eggs [24,156]. Clutch sizes of 1st nests range from 9.5 (Haulton 1999 cited in [156]) to 12.7 eggs [119]; these are larger than 2nd-nest averages of 7.0 [5] to 7.5 eggs (Bump and others 1949 and Rusch personal observation cited in [156]). In the Appalachian region, average clutch size of 368 nests was 9.86 eggs; clutches were small in nests initiated late [34]. Adult and yearling clutch sizes did not differ in Wisconsin (Small and others 1996 cited in [156]), Michigan (Larson 1998 cited in [156]), Minnesota (Maxson 1974 cited in [156]), or the southern Appalachians (Haulton 1999 cited in [156]).
The sparse data available indicate that about 45% to 65% of nests produce at least one chick. In northern Lower Michigan, average annual production was 3.4 hatchling females/adult female, and fall recruitment was 1.0 juvenile female/adult female [119]. Mean lifetime reproductive success, calculated from data on 20 hens over a 1-year period in Wisconsin, was estimated at approximately 9.3 chicks. Sixty percent of these hens produced chicks that survived to leave the nest (Rusch personal observation cited in [156]). In the Appalachians, just under 70% of hens hatched at least one chick ([34], Haulton 1999 cited in [156]). Reports of nest success from several locations (see Table 2) show that generally more than half of eggs hatch, and only about 50% to 75% of nests produce at least one egg. Parasitism of ruffed grouse nests by ring-necked pheasants (Phasianus colchicus) and wild turkeys (Meleagris gallopavo) has been documented, although it is uncommon [156].
Table 2. Ruffed grouse nest success at several locations. Cells are blank where information was not available in the study cited. Location % eggs that hatched % nests with ≥1 egg hatched Wisconsin 44.9% of 256 eggs (Rusch personal observation cited in [156]) 48% (Small and others 1996 cited in [156]) Northwestern Wisconsin 53% [5] Michigan 48% (Larson 1998 cited in [156]) Lower Michigan96% in 1st nests
83% in 2nd nests
44% of 1st nests
79% of 2nd nests [119]
New York 61.4% (Bump and others 1947 cited in [156]) West Virginia 91.0% [36] Central and Southern Appalachians 63% [199] Southern Appalachians median: 82% 66% [34] 94% of 482 eggs (Haulton 1999 cited in [156])Several factors influence nesting success and recruitment, including weather, food availability, location, and habitat structure. According to a review, cold, wet weather in May and June reduces nesting success and may cause high losses among broods (Edminster 1954 cited in [24]). In the Appalachian region, the best supported model of nest success included average minimum temperature in March and April, production of hard mast such as acorns, and their interaction [34]. (See Forage quality for information on the effects of diet quality in various habitats on ruffed grouse reproductive output and other population parameters.) Ruffed grouse productivity and recruitment in the Appalachian region were lower than in more northern portions of the species' range [34]. A review also mentions generally lower recruitment in southern populations. South of latitude 42° 3' N, 39% to 57% of ruffed grouse populations are immature in fall, while 63% to 78% of more northerly populations are immature (Davis and Stoll 1973 cited in [24]). During times of population increase, recruitment rate may be as high as 80% (Dorney 1963 cited in [24]), while low recruitment rates result in large-scale population declines and slow recovery from population lows (Gullion 1971 cited in [24]). See Preferred Habitat for information on habitat effects on reproductive output.
Ruffed grouse are closely associated with aspen, typically quaking aspen, year-round in the northern United States and Canada [29,156]. Based on survival on 3 of 4 sites from 1 August to 15 May, long-lived ruffed grouse (> median survival) in Michigan had significantly (P≤0.081) more young aspen (<10 yrs) in their activity ranges than short-lived ruffed grouse. Risk of ruffed grouse mortality declined with increased amount of aspen less than 30 years old on 3 of 4 Michigan sites [22]. Occurrence of quaking aspen is highly correlated with ruffed grouse densities [98]. In the Cloquet Forest Refuge in Minnesota, 10- to 25-year-old aspen stands had 1 ruffed grouse pair/ 7 acres, while upland pine and spruce-fir-tamarack (Larix laricina) lowland forest had few or no ruffed grouse [63]. In contrast, managed oak forest sustained higher ruffed grouse densities than managed aspen forests in Pennsylvania (McDonald and others 1994 cited in [134]). In north-central North Dakota, ruffed grouse occurrence was positively (P<0.01) associated with the area of aspen groves [58]. On the Black Hills National Forest, the probability of ruffed grouse occupancy increased an average of 5.7% with every 12.4-acre (5 ha) increase in the area of quaking aspen within 1,800 feet (550 m) [76]. In central Alberta, although quaking aspen woods comprised only 20% of the study area, 74% to 92% of all flushes, 96% of drumming logs, and 97% of brood flushes occurred in this community over 2 years [157]. In southeastern Idaho, ruffed grouse selected (P<0.05) stands dominated by quaking aspen year-round and mixed quaking aspen-conifer stands from spring to fall [179]. In Minnesota, only 3 of 256 drumming logs were out of sight of a mature male aspen [63], and in Maine 95.6% of all drumming sites were within sight of a mature male aspen [160]. In north-central Wisconsin, over 60% of drumming males occurred in aspen sapling stands, which comprised 21% of the total habitat [133]. In Pennsylvania, unmanaged pole-sized and saw-timber aspen-black cherry stands were used more than expected based on availability during breeding and summer seasons (P≤0.0023) [134]. During a ruffed grouse population low in Minnesota, aspen communities had higher ruffed grouse carrying capacities than conifer forests, and male ruffed grouse strongly selected young aspen stands. However, they did use other forest types, even where unoccupied young aspen stands were available [215].
Kirk Piehler; USDA FS Hiawatha National ForestPine and boreal spruce forests may provide lower-quality habitat than hardwood forests, including aspen woodlands. In forests of northern Minnesota, ruffed grouse with activity centers in pure hardwood forests survived an average of 19.3 months, while average survival of those with activity centers in closed-canopy pine stands was 12.6 months (P<0.025) [60,61]. Densities were also lower in conifer than in hardwood forests [60]. Variations in densities in broad regions of the ruffed grouse range are provided in Table 4. Lower survival in boreal forests suggests they provide lower-quality habitat than aspen communities (Gullion 1967a, Gullion and Marshall 1968, and Rusch and Keith 1971a cited in [156]). In Michigan, short-lived ruffed grouse had greater (P<0.02) amounts of lowland hardwood communities in their activity ranges than long-lived birds in 1 of 2 study areas [22].
Table 4. Densities of ruffed grouse in various plant communities Plant Community Density (number/100 acres) Aspen-birch woodlands 6 males [132] Boreal forest region1.4-10 spring, 25-29 fall;
≥55.5 in fall during population peaks
Reproductive success may be lower in oak or oak-hickory communities than in other hardwood plant communities. Nesting rate, renest rate, clutch size, productivity, and recruitment were lower in oak-hickory forests than in mixed-mesophytic forests of the central and southern Appalachian region. Nest success did not differ between the 2 forest associations [34]. In Minnesota, nest success was 89% in mixed hardwoods and 25% in oak woodlands (Maxson 1978a cited in [24]). Increased structural diversity of mixed hardwood communities may reduce predator effectiveness (Godfrey 1975b cited in [24]). However, survival of ≥2-month-old ruffed grouse was greater in oak-hickory than in mixed-mesophytic forests of the Appalachian region [34]. Chick survival rates follow a general trend of lower survival in more southern locations (see Table 1). Forage quality has been suggested as a possible cause of differences between ruffed grouse populations in oak-hickory and other hardwood plant communities.
Ruffed grouse have shown selection for habitats such as mixed conifer/hardwood stands, mesic hardwood communities, and scrub oak and avoidance of others such as pitch pine/scrub oak (Pinus rigida/Quercus ilicifolia and Q. prinoides), upland hardwood, and conifer habitats. Ruffed grouse females selected (P<0.001) mixed deciduous and conifer stands in winter in Ontario [11]. In Rhode Island, ruffed grouse home ranges included more (P<0.05) conifer/hardwood habitat than expected based on availability [43], and in central Missouri, eastern redcedar-hardwood communities were preferred over all other plant communities year-round and comprised more of spring and summer home ranges than expected in the study area (P<0.05) [194]. Mesic deciduous stands with a rhododendron-mountain-laurel (Rhododendron spp.-Kalmia latifolia) understory were selected (P<0.01) in southwest Virginia [46]. In spring and summer ruffed grouse, especially females, exhibited stronger selection for mesic bottomlands in oak-hickory forests than in other plant communities [205]. In central Missouri, male ruffed grouse demonstrated a strong preference for oak-hickory with a dense understory: Their home ranges had more of this vegetation type than would be expected in the study area, and ruffed grouse use of these plant communities was greater than would be expected based on occurrence within the home range (P<0.05) [194]. Ruffed grouse were associated with high bear oak (Q. ilicifolia) cover in plots in southeastern Massachusetts [56]. Brooding females selected (P<0.05) mixed oak/scrub oak and avoided pitch pine/scrub oak communities in central Pennsylvania [166]. Other communities avoided by ruffed grouse include upland hardwoods in Michigan [22] and mixed oak sawtimber in Pennsylvania [134]. Conifer habitats were avoided by ruffed grouse in Rhode Island [43] and by females with broods in Quebec (P<0.0001) [54].
Predation is the major source of ruffed grouse mortality, with avian predators typically responsible for the most mortality [22,34,156]. Based on a review of the limited literature available, Hewitt and others [82] estimated that on average, about 80% of nest lost is due to predation. In the Appalachian region, predation and exposure each caused 44% of known chick mortalities [173]. Predation was responsible for 78% of juvenile mortality on private lands and 54% of juvenile mortality on public lands in a Wisconsin study area (Small and others 1991 cited in [82]). Avian predation caused 77% of mortality in northern Michigan [22], 46.2% in Wisconsin (Rusch personal observation cited in [156]), and 44% in the Appalachian region [34]. Mammalian predation caused 6% to 28% of mortality on these sites ([22,34], Rusch personal observation cited in [156]). In western North Carolina, mammalian predators were responsible for the most mortality, 42.6%, although this report may be skewed by mammal scavenging on dead birds [101]. Although predation causes substantial ruffed grouse mortality, it rarely limits populations (Gullion 1971 cited in [24]). Two studies indicate that predator control does not increase ruffed grouse densities [82].
Ruffed grouse eggs are eaten by American mink (Mustela vison), fishers (M. pennanti), other weasels (Mustela), skunks (Mephitidae), red foxes (Vulpes vulpes), northern raccoons (Procyon lotor), American crows (Corvus brachyrhynchos), common ravens (C. corax), black racers (Coluber constrictor), and black ratsnakes (Elaphe obsoleta obsoleta) [82,156]. In West Virginia, northern raccoons, American black bears (Ursus americanus), and black ratsnakes have been reported to disturb or destroy ruffed grouse nests [36,174]. Chicks, juveniles, and adults are eaten by several of the previous species as well as grey foxes (Urocyon cinereoargenteus), coyotes (Canis latrans), Canada lynx (Lynx canadensis), bobcats (L. rufus), and several species of raptors including northern goshawks (Accipiter gentilis), northern harriers (Circus cyaneus), great horned owls (Bubo virginianus), and barred owls (Strix varia) [24,82,156].
Ruffed grouse are associated with certain overstory characteristics on some sites. Ruffed grouse selected areas with 80% to 85% tree cover in all seasons in quaking aspen and quaking aspen-mixed conifer communities in southeastern Idaho [180]. In oak-hickory forests of Missouri, ruffed grouse density was positively correlated (P=0.01) with basal area above 16.9 m²/ha and quadratically related with canopy cover, peaking in the 70% to 80% range [207]. In aspen stands of Minnesota, ruffed grouse abundance was positively associated with density and size of live trees and density of large dead trees [163]. In contrast to the above results, ruffed grouse abundance in quaking aspen-mixedwoods of Alberta—which are typically comprised of quaking aspen, paper birch, white spruce (Picea glauca), black spruce (P. mariana), balsam poplar (Populus balsamifera subsp. balsamifera), and/or jack pine [74,86]—was positively associated with willow density and density of trees <8 inches (20 cm) DBH; it was negatively associated with density of trees >8 inches DBH (P<0.01) [161].
Coarse woody debris is apparently beneficial for ruffed grouse breeding and brooding areas to some extent. Drumming males use downed logs, although the variability of the drumming platforms suggests that a lack of downed logs may not necessarily have negative impacts on drumming habitat. At 8 study sites in the central and southern Appalachians, the likelihood of a successful nest increased with increasing cover of large-diameter coarse woody debris (≥6 inches (15 cm)) [199]. Broods occurred on sites with more coarse woody debris than random sites [196]. In an oak, northern hardwood, and pin cherry (Prunus pensylvanica)-aspen forest mosaic in Pennsylvania, every 10% increase in coarse woody debris cover was associated with a 0.008 increase in daily survival rate [197]. In contrast, it has been suggested that, at least in aspen communities, coarse woody debris provides better cover for predators than for ruffed grouse and impedes brood movement [60,63]. Movement of chicks and growth of ruffed grouse plant foods may be inhibited by logging slash [204].
Ruffed grouse may be limited to higher elevations in the South. Based on ruffed grouse's absence from seemingly suitable habitats in Louisiana to Georgia, its restriction to areas above 1,500 feet (460 m) in the southeastern portion of its range, and the lack of an elevation effect in other parts of its range, Thompson and Dessecker [192] conclude that "southern climates are inhospitable to ruffed grouse." In contrast, O'Keefe and Sumithran [142] suggest that occurrence of ruffed grouse at mid- and high elevations of the Appalachians may be due to avoidance of thermal inversions, when cold air settles in mesic bottomlands. However, use of high elevations may reflect greater availability of habitat in these locations. In their study area, season did not affect use of various elevations, juveniles used a wider elevational gradient than adults, and females occurred at lower elevations than males of the same age [142]. Ruffed grouse in northern Idaho also selected habitat based on topography and associated thermal inversions. They used ridges and upper slopes in winter and spring and moved downslope as the summer progressed. Broods used valley bottoms in the day and moved 50 to 130 feet (15-40 m) upslope to roost at night [92]. Ruffed grouse in ponderosa pine and Douglas-fir-spruce in Idaho occurred at middle elevations throughout the year [130]. In winter in Ontario, female ruffed grouse selected (P<0.001) midslope locations [11].
High stem density of the shrub-small tree layer is likely the most important characteristic of ruffed grouse cover [27,32,63,192]. A dense shrub layer protects ruffed grouse from avian predators [32,192] and may also provide cover during inclement weather [27]. In quaking aspen and quaking aspen-conifer stands in southeastern Idaho, drumming, summer, and autumn locations occurred where the density of small stems was higher than that of random samples (P<0.05) [180]. In southeastern Idaho, ruffed grouse selected areas with the highest shrub densities in spring [179]. A minimum density of 2,000 stems/acre [32,63] at least 5 feet (1.5 m) tall [32] has been recommended, and a review notes that cover is optimal in stands with about 6,000 to 8,000 stems/acre [24]. Areas with trees and shrubs at least 3 feet (1 m) tall occurring at densities of 6,000 to 25,000/acre provide excellent cover in hardwood stands (Kurzejeski and others 1987, Laubhab 1987, and Stoll and others 1979 cited in [192]). In aspen stands in Minnesota, ruffed grouse were positively associated with shrub density and shrub species richness [163]. In contrast, ruffed grouse were negatively associated with shrub species richness in quaking aspen-mixedwoods of Alberta [161].
A dense shrub layer also shades out groundlayer plants, making for high visibility at ground level. Increased visibility at ground level might increase detectability of approaching predators and allow for easier movement [192]. Gullion [63] suggests that the best aspen cover has a 50- to 60-foot (15-18 m) visibility radius at ground level. However, there is neither documentation of habitats with groundlayer vegetation too dense for ruffed grouse [33] nor any study specifically investigating the impact of groundlayer visibility on habitat selection, predation rates, pairing rates, or other indicators of habitat quality.
Habitat characteristics required at various life stages and different seasons are described below:
Drumming: Drumming habitat is similar to general cover required by ruffed grouse in that it has high shrub and/or small tree densities and high groundlayer visibility [33,156,192]. In western Washington, drumming logs had a visibility radius of 51 feet (15.5 m). On this site, drumming occurred in April before new vegetation reduced visibility [158]. Logs used for drumming provide good visibility at ground level [192]. Some overhead cover is apparently required on many sites [29,156], and topography is variable.Shrub densities are high on drumming sites. According to a review, understory stem densities on drumming sites range from about 3,000 to 5,000/ha in Alberta and Ontario to 30,000 to 33,000 in the Great Lake states [156]. In northern Wisconsin, high shrub density was the most important factor influencing drumming site selection [33]. In southwestern Alberta, ruffed grouse occupancy and recruitment were significantly less and movement to secondary drumming logs was significantly greater in an area where stem density had been reduced compared to an untreated area [15]. Shrub density [185] and subcanopy cover [158] were greater at repeatedly used drumming sites than at infrequently used sites in Ohio [185] and in western Washington [158]. In Ohio, areas used nearly continuously by drumming ruffed grouse had 3 times as much brushland and heavily cut woodland (P≤0.05) as areas that were occupied by only one drumming male during the study [185]. In pine, aspen, and northern hardwood communities in northeastern Minnesota, drumming sites had greater stem density than unused sites [213]. Cover from 1 to 10 feet (0.3-3.0 m) around drumming logs in Grand Teton National Park in Wyoming was significantly (P≤0.044) greater than around random logs [20]. In southeastern Idaho, drumming sites had more small stems than other sites selected by ruffed grouse in spring [180]. In western North Carolina, midstory density and vertical vegetation density were greater (P<0.05) at drumming logs than at random logs, although the difference between woody understory density at drumming and random logs was not significant [164].
Dense shrubs without canopy cover may not provide suitable drumming habitat in some areas, including northern Wisconsin [33] and central Alberta (Rusch and Keith 1971 cited in [156]). Canopy cover was greater (P<0.05) at drumming sites than around random logs in northwestern Wyoming [20], greater than other sites selected in spring on a site in southeastern Idaho [180], and greater than sites 66 feet (20 m) away from drumming sites on a study area in Maine. On this site, canopy cover at drumming sites averaged 76.7%, while the average of paired sites 66 feet away was 64.6% [160]. On a site in western Washington, the average canopy cover at drumming sites was 62% [158]. Cover of conifers was greater (P<0.05) at drumming sites than other sites selected in spring in southeastern Idaho [180] and greater than at random logs in northwestern Wyoming [20]. Canopy height was greater at drumming logs than random logs [20]. In a review of quaking aspen forests of the West, drumming sites are described as having high overhead cover [29]. However, a review of early successional forests in the Central Hardwoods region states that canopy cover at drumming sites is variable and notes the occurrence of drumming in areas with little to no canopy cover [192]. In addition, it has been suggested that canopy cover more than about 60% could increase ruffed grouse mortality from raptors, especially if comprised of conifers (Gullion 1967b and Gullion 1970 cited in [156]).
Basal area was lower at drumming sites than unused sites in western Washington (P<0.001) [158] and northeastern Minnesota [213]. In contrast, there was no difference between the basal area of plots with drumming logs and those with random logs in western North Carolina [164].
Ruffed grouse drumming habitat often occurs in young stands. Males in Missouri [112] and Minnesota [215] selected young stands for drumming. In Pennsylvania, breeding males only occurred in areas that had been clearcut 3 times. The 3rd cut nearly doubled the amount of young shrubby vegetation compared to the area cut twice [209]. However, drumming has also been observed in mature forests [20,23,158] (see Stand ages).
Topography of drumming sites is generally not steep. In Maine the majority of drumming sites occurred in lowlands [160], while in western North Carolina over 85% of drumming logs occurred on ridgetops [164]. In the Central Hardwoods region, male ruffed grouse often selected drumming logs at the bases and tops of slopes <25° [192]. Drumming logs occur on fairly level ground [158,192] and along contours of slopes up to about 25° [24,192].
Drumming platform characteristics: Although logs are often used as drumming platforms, several other surfaces are also used including large rocks, roots [156,160,192], dirt mounds [156,192], stumps [160,192], and structures such as culverts [156] and rock walls [160,192]. In Maine these structures were used in over 50% of drumming sites. Average height of rock platforms was 44 inches (112 cm) above ground [160]. Since these features are common, they are not thought to limit the distribution of drumming ruffed grouse [156,214]. In a mosaic of primarily pine (P. resinosa and P. banksiana) and aspen (mainly P. tremuloides with some P. grandidentata) stands in Minnesota, male ruffed grouse used logs more than other structures for drumming. Despite agreeing that drumming structures are not typically limiting, Zimmerman and Gutierrez [214] suggest that "the paucity of logs in a particular area could reduce ruffed grouse abundance locally". A review notes that vegetation structure surrounding platforms influences ruffed grouse selection more than the characteristics of the platform [192].
There are usually 1 to 2 drumming logs per territory [156]. In western Washington, there was an average of 1.83 logs/territory [158]. Neighboring drumming sites are typically over 492 feet (150 m) apart, but drumming sites as close as 174 feet (53 m) have been observed [156]. Reviews note drumming logs are typically more than 6.6 feet (2 m) [156] to 10 feet (3 m) [192] in length. They may be much longer: In western Washington, length averaged 34.5 feet (10.5 m) [158] and in Maine, 30 feet (9 m) [160]. The longest drumming log reported in a review was 65.5 feet (20.0 m) [192]. Drumming logs are typically about 8 [156] to 16 inches (20-40 cm) in diameter [160,192]. However, diameter of drumming logs in western Washington averaged much bigger, 27 inches (69.5 cm) [158]. The drumming platform is often 17 to 22 inches (43-55 cm) from ground level [160,192]; although in western Washington, the average was higher, 24.8 inches (63 cm) [158]. In the Central Hardwoods region, the species of drumming logs reflected species availability (Stoll and others 1979 and Boag and Sumanik 1969 cited in [192]). Logs are typically decayed [20,192], but in at least some circumstances are still firm [20]. In Grand Teton National Park, drumming logs have less bark and fewer limbs than random logs (P≤0.003) [20]. Frequently-used logs in mixed mesophytic forest of Ohio were typically sound without bark, although significantly more had bark than infrequently-used logs (P<0.05) [185]. In western North Carolina, no significant differences were found between characteristics of drumming logs and random logs [164].
Nesting: Nesting habitat is the most variable of ruffed grouse habitats. It ranges from comparatively open [66] midseral (Bump and others 1947, Gullion 1969, and Maxson 1978a cited in [24]) or mature stands [66] comprised of pole-sized or larger trees [192] to stands "similar to drumming habitat" in western quaking aspen forests [29]. Nests in New York occurred in stands of any age but were often in midseral stands that were near edges or openings and standing water (Bump and others 1947 cited in [24]). Several reviews include high groundlayer visibility as a feature of nesting sites [29,156,192]. The Birds of North America [156] review also describes dense overstory cover, open understories, and trees from 2 to 8 inches (5-20 cm) DBH as characteristic of ruffed grouse nesting habitat. It notes that although nests may occur in wet shrubby areas, they rarely occur in dense vegetation [156]. Nests themselves are often placed at the base of a tree [156,192], stump, shrub, boulder [156], or log [192]. However, they sometimes occur in areas without an object nearby [156]. In Minnesota, most females selected nesting sites where they could fly from the nest directly to the male aspens they used for foraging (Barrett 1970, Kupa 1966, and Schladweiler 1968 cited in [66]).
Basal area has been associated with nest success and brood survival. In the central and southern Appalachians, nest success was positively related to basal area, coarse woody debris, and deciduous canopy cover and negatively related to ground cover and areas farther than 330 feet (100 m) from a road or opening [199] (see Brooding below). Based on predation on artificial ground nests in oak-hickory forests of Pennsylvania, Yahner and others [210] concluded that timber harvesting that leaves 23 to 46 m²/ha basal area would not negatively affect nesting success of ground-nesting galliformes, such as ruffed grouse or wild turkey. No relationship between habitat structure and nest success was observed in New York (Bump and others 1947 cited in [24]) or northern Lower Michigan, although this study was limited by small sample size [119].
Brooding: Relatively open areas with a moderate to dense ground layer and a well developed herbaceous component provide the cover and forage needed for ruffed grouse broods [24,156].
High herbaceous cover is a common component of brood habitat [29,60]. It contributes to availability of insect prey [192,197] and provides protection for broods [60,197]. Sites used by broods had greater ground cover than sites used by solitary birds in quaking aspen and mixed quaking aspen-conifer stands in southeastern Idaho (P<0.05) [180], random sites in Virginia and West Virginia (P<0.1) [78], and random sites in mixed-hardwood forests in western North Carolina (P<0.05) [103]. Broods 5 weeks old or less in Pennsylvania occurred on sites with greater herbaceous ground cover than would be expected based on availability. With each 10% increase in percentage ground cover, broods were 70% more likely to occur [197]. Herbaceous vegetation was significantly taller on sites used by broods than sites used by solitary birds in quaking aspen and mixed quaking aspen-conifer stands in southeastern Idaho (P<0.05) [180] and random sites in Virginia and West Virginia (P<0.1) [78]. Sites used by broods at night had more (P<0.001) concealing cover <3 feet (1 m) above ground than random sites in central Pennsylvania [196]. In mixed deciduous and conifer forests in Quebec, lateral obstruction from 0 to 6.6 feet (0-2 m) was greater (P<0.01) at brood sites than random locations, but percent of herbaceous ground cover less than 19.7 inches (50 cm) tall was not [54].
Small forest openings are often used by ruffed grouse broods, likely due to their association with greater herbaceous cover and availability of both plant and invertebrate food. Ruffed grouse broods occurred in sites closer to edges and openings than in random sites in aspen/scrub oak and mixed-oak communities in central Pennsylvania (P≤0.006) [166], and brood locations had greater percent open area than locations of solitary ruffed grouse in quaking aspen and mixed quaking aspen-conifer stands in southeastern Idaho (P<0.05) [180]. Summer use of a right-of-way by ruffed grouse 2 years after clearing was more than 14 times the use of a control (≥8 years since cutting) and 124% to 400% the use before treatment. Increased food availability was suggested as a factor in the increase [40]. Clearing vegetation in oak-hickory forests of Pennsylvania also increased availability of plant and invertebrate food sources, which declined as the opening aged and became shaded [168]. In Pennsylvania, broods 5 weeks old or less occurred in landscapes containing higher proportions of roads than would be expected based on availability. Roads were typically gated or were old logging roads with well-developed herbaceous layers and either had a forest canopy or were adjacent to a canopy. Survival of broods increased as distance to roads decreased, with broods close to roads exhibiting daily survival rates of 0.962 and those far from roads having survival rates of 0.926. It should be noted that at the landscape scale, density of roads was negatively associated with brood survival. Every 1% increase in road density was associated with a 0.004 decline in daily brood survival rate [197]. Broods surviving 5 weeks from hatching used forest roads and the edges of maintained openings in mixed-hardwood forests in western North Carolina [103]. In mixed deciduous and conifer forests in Quebec, females with broods occurred closer to roads than random locations (P<0.018) [54]. Openings may provide more forage than closed-canopy sites due to increased light levels supporting more food species and greater fruiting [24], but they may pose a greater risk from predators [192].
Direct, positive relationships between ruffed grouse brood occurrence and forage availability have been found on some sites. Sites used by females with broods in the 3 weeks following hatching had more arthropods than random sites in Virginia and West Virginia (P=0.02) [78] and greater invertebrate density than random sites in mixed hardwood forests in western North Carolina (P<0.05) [103]. According to a review, broods are commonly associated with high shrub cover and an abundance of food plants [24].
A review notes that broods in aspen communities are associated with high stem densities [24]. In mixed-deciduous and conifer forests in Quebec, small stem (≥20 inches (50 cm) tall; <3.5 inches (9 cm) DBH) densities were greater (P<0.01) at brood sites than random sites [54]. In an oak, northern hardwood, and pin cherry-aspen forest mosaic in Pennsylvania [197] and in aspen/scrub oak and mixed-oak communities in Pennsylvania (P<0.001) [166], small (<3.2 inches (<8 cm) DBH) stem densities were greater at brood sites than what was generally available in the study area. In the study in the forest mosaic, an increase of 1,000 stems/ha was associated with about a 12% increase in the likelihood of broods using a site [197]. Although stem densities were higher in brood sites, areas of high stem density were of secondary importance to ground cover in Pennsylvania [197] and western North Carolina [103]. In Virginia and West Virginia, total woody stem densities were not different (P>0.1) between brood and random sites [78]. In southeastern Idaho, broods used locations with lower small (<2.8 inch (7 cm) DBH) stem densities than used by solitary ruffed grouse (P<0.05) [180]. In a mosaic of stands dominated by aspen or pin cherry, sweet birch (Betula lenta), red maple in central Pennsylvania, chick survival exhibited a weak negative (P=0.037) association with small (≤3.2 inches (≤8 cm) DBH) woody stem density [196].
Conditions required for brood cover and forage often occur in stands 10 [24,32,166,192] to 20 [54,103] years or younger but also occur in mature stands. In mixed-deciduous and conifer forests in Quebec, females with broods selected habitat based on stand age, showing a preference for 2- to 20-year-old stands and avoiding 60- to 100-year-old stands and old, uneven-aged stands. Females with broods also selected stands based on time-since-clearcutting, with 11- to 20-year-old clearcuts selected and partial cuts and uncut stands avoided (P<0.05) [54]. In North Carolina, brooding females selected 0- to 20-year-old mixed-oak forest [103]. In central Pennsylvania, females with broods avoided an area less than 2 years old and selected 10-year-old clearcuts [166]. In oak-hickory forest of Pennsylvania, 21 of 24 broods used 1- to 5-year-old clearings; after 7 growing seasons, white oak (Quercus alba) and scarlet oak (Q. coccinea) shaded out understory vegetation, so food plants and fruiting declined and broods used these areas less frequently [168]. Broods used 20- to 50-year old hardwood stands in Iowa (Porath and Vohs 1972 cited in [24]), intermediate and mature aspen in northern portions of the ruffed grouse's range [156,183], and greater than 80-year-old mixed hardwoods in North Carolina. Selection of mature forests in North Carolina is likely due to canopy gaps contributing to early-successional habitat structure [103].
In some areas, broods are associated with lowlands, such as those dominated by alder. Greater use of mesic lowlands by broods compared to adults has been noted in several reviews [24,156], including those focusing on the Central Hardwood [192] and western regions [29,183]. Broods used lowland alder habitat almost exclusively in a Wisconsin study area [39], and in Minnesota brood sites usually occurred in dense alder thickets [60].
Importance of overstory apparently varies with location. In a mosaic of stands dominated by aspen or pin cherry, sweet birch, and red maple in central Pennsylvania, nocturnal brood habitat had greater deciduous cover than random sites (P<0.001) [196]. Broods on sites in Virginia and West Virginia used sites with more than 70% canopy cover, which was more than that of random sites [78]. Sites used by broods in western North Carolina had 75% canopy cover [103]. In contrast, ruffed grouse broods in quaking aspen communities in the western United States may use stands with more open canopies than those used by ruffed grouse broods elsewhere [29]. Broods in quaking aspen and mixed quaking aspen-conifer stands in southeastern Idaho used sites with less deciduous cover than that of locations used by solitary ruffed grouse (P<0.05) [180].
In a mosaic of stands dominated by aspen or pin cherry, sweet birch, and red maple in central Pennsylvania, nocturnal brood habitat had more coarse woody debris than random sites (P<0.048) [196].
Foraging: Foraging habitat varies based on season and ruffed grouse life stage. The types of forage eaten at different times of year give a general idea of the foraging habitat use (see Temporal and spatial variation in the diet). For instance, areas with well-developed herbaceous vegetation and shrubs are often used in summer and may be important from fall to spring in southern [156,167,178] and central regions [186], including the temperate deciduous forests. Catkins, buds, and twigs of trees are used from fall to spring [24]. In quaking aspen stands in central Alberta, winter feeding sites had significantly higher tree densities (>4 inch (10 cm) DBH) than systematic-grid stations, drumming log locations, and sites where ruffed grouse were shot [38]. In fall and winter in southeastern Idaho, ruffed grouse may have selected sites with high overstory cover in order to forage on quaking aspen buds [179]. In Ontario, total canopy cover was greater on female ruffed grouse locations than random locations in winter [11]. See Forage quality for information on possible explanations for the importance of aspen in diets of ruffed grouse in northern areas and the forage value of other community types, and see Brooding for information on areas where broods forage.
During much of the year, foraging occurs in mature habitats. In aspen, foraging is typical in stands 25 years or older [24,32,38,60,63]. In central Alberta, the average age of 100 male quaking aspen that ruffed grouse used for feeding was 36 years [38]. According to a review, ruffed grouse use midseral hardwoods for foraging in northern mixed forests [24].
Roads likely provide foraging for adult ruffed grouse as well as for broods. Roads and trails were selected by female ruffed grouse on 10 sites in the Appalachian region. This selection was stronger in years with poor mast crops, suggesting that these areas provide alternate foraging areas when preferred food is scarce [205]. On a site in Tennessee, converted logging roads had the greatest biomass of arthropods of the sites investigated [88]. Roads were also selected by ruffed grouse in an oak-hickory forest of Rhode Island [43]; in North Carolina, they were selected by females year-round and by males from fall to spring [102]. The importance of roads as foraging habitat in these areas was not discussed.
Other communities that often provide foraging opportunities include old fields and mesic bottomlands. In the Central Hardwoods region, old fields provide diverse of fruiting shrubs [192]. On 10 Appalachian study sites, female home range size decreased with increasing amounts of mesic bottomland, possibly due to the occurrence of important forage species [206].
Winter cover: In winter, ruffed grouse may select for conifer habitats, while stem density of sites used in winter varies. Female ruffed grouse winter locations had greater coniferous cover at all layers (P<0.05) and higher coniferous stem density and basal area (≥3.5 inches (9 cm)) than random sites. This may be related to the use of conifers for cover in inclement weather [11]; see Winter roosting below. In quaking aspen and mixed quaking aspen-conifer stands in southeastern Idaho, ruffed grouse selected sites in winter with significantly (P<0.05) fewer small stems than those selected by drumming males or females with broods [180]. In contrast, stem densities were greater on winter roost sites than random sites on a Missouri study area [193] and on 3 oak-hickory sites in West Virginia [203]. In winter in Ontario, females selected stands greater than 56 feet (17 m) tall and avoided stands 5 to 13 feet (1.5-4 m) tall (P<0.001). Winter locations have also been associated with greater canopy cover than locations selected in other seasons (see Foraging).
Winter roosting: Ruffed grouse roost at night and during the day in inclement weather. According to reviews, roosts often occur on the ground and in deciduous or coniferous trees [24,156]. Conifers are often used in hot [24], cold [156], or wet [24,156] weather. Ruffed grouse often roost alone but may roost in groups in winter [156,203]. On 3 oak-hickory sites in West Virginia, inversions lowered temperatures in valley bottoms in the evenings and nights, so ruffed grouse roosted in bottomlands more during the day than at night [203]. Most information regarding ruffed grouse roosts was collected during winter.
When available, ruffed grouse often roost in burrows in light, soft snow [156]. These provide the best thermal cover. In northern Minnesota, temperatures 7 to 10 inches (18-25 cm) under the snow remain fairly constant (about 20 °F to 25 °F (-6.7 °C to -3.9 °C)), despite temperatures 6 inches (15 cm) above the snow as low as -42 °F (-41 °C) [61]. In a Missouri study area comprised of upland oak-hickory, mixed eastern redcedar-hardwoods, and bottomland hardwoods, ruffed grouse temperature stress and metabolic rate were lower in snow roosts than open areas, resulting in less heat loss and greater energy savings in both calm and breezy conditions. Of 6 roosts located when conditions were adequate for snow roosting, 5 occurred in the snow [193]. In mixed-deciduous and conifer forests in Ontario, 36.3% of roosts occurred in snow burrows. In a moderate wind, female ruffed grouse were more likely to roost in snow burrows than in trees or on the snow surface (P<0.05). In deciduous stands, snow burrows were used significantly (P<0.05) more often than other types of roosts. The proportion of snow burrowing was negatively correlated with air temperature (P=0.01) and positively correlated with depth of snow (P<0.05) in 1 year of a 2-year study [12]. For ruffed grouse to roost in snow, they need crust-free snow [61] at least 8 to 10 inches (20-25 cm) deep [61,193]. Snow burrows are also effective cover from predators [61].
Ruffed grouse also roost in trees, most often conifers, in the northern ([12], Bump and others 1947 cited in [24]), western [29], and Central Hardwoods regions [193], but tree roosts may be most important where snow conditions are rarely adequate for burrowing [24,193]. Although snow provided better thermal cover, snow was rarely adequate for roosting on a site in Missouri. Eastern redcedar roosts, either on the ground near or in the tree, provided better thermal cover than open sites or deciduous stands. Eastern redcedar roosts were selected (P<0.05) by ruffed grouse and used for 86.8% of roosts. On this site, deciduous stands were avoided for roosting [193]. In contrast, on 3 oak-hickory sites in West Virginia, evergreens were not selected for winter roosting, and many roosting sites occurred on the ground in oak litter. Possible explanations for this trend included superior thermal protection provided by oak litter, evergreens species available on the site being inferior to evergreens typically used, conifers occurring in bottoms where inversions create cool temperatures, and/or avoidance of predators in evergreen habitats. Evergreens included conifers, mountain-laurel, and rhododendrons [203]. In winter in a mixed forest in Ontario, 41.2% of female ruffed grouse roosts occurred in trees. In calm conditions, female ruffed grouse were more likely to roost in trees than in snow burrows or on the snow surface (P<0.05). In uneven-aged and 21- to 60-year old stands, roosts were significantly (P<0.05) more likely to occur in trees than in snow burrows or on the snow surface. Proportion of tree roosting was positively correlated with temperature (P=0.001). Tree roosts represented 41.2% of roosts when conditions were adequate for snow burrowing. Despite snow burrowing resulting in the best energy conservation, it may not allow for regular feeding activities. This may have influenced the substantial use of tree roosts on this site, where ruffed grouse are able to move discreetly from coniferous cover to foods in deciduous vegetation [12]. Gullion [63] suggests that in northern Minnesota, conifers provide no benefit and reduce the quality of ruffed grouse habitat (see Plant associations used as habitat). According to a review, conifers probably have greater value for roosting in northern mixed forests than in boreal forests [24].
In some circumstances ruffed grouse roost on the ground. In winter in a mixed forest in Ontario, 22.4% of female ruffed grouse roosts were on the surface of the snow (22.4%). On cloudy days, however, ruffed grouse were significantly less likely to roost on the snow than in the snow or in trees (P≤0.05) [12]. On 3 oak-hickory sites in West Virginia, 55% of winter roosts were on the ground in nest-like depressions in oak litter up to 12 inches (30 cm) deep. Ground roosting was less common when it was raining and more common when it was snowing, suggesting that the leaf litter provided good thermal cover when dry. One ruffed grouse in this study burrowed into the leaf litter, completely covering itself [203].
Ruffed grouse require both early-successional and mature forest habitats. Broods use the youngest aspen and other eastern deciduous stands compared to other age groups [60]. Peak densities and year-round use occur in stands that are about 5 to 10 years old [30,60,63,133,154,192] and continue until stands are about 25 years old [24,30,60,133,154,192]. In grand fir (Abies grandis) forests of the Blue Mountains of Oregon and Washington, ruffed grouse were most abundant in young, multistory forest [100]. At ages of 25 years or more, stands are typically used mainly for foraging [32,38,60,63] but may be used as breeding sites in both the eastern [60,102] and western [20,23,158,195] United States. Specific information on the age of stands used for various purposes are provided in the drumming, nesting, brooding, foraging, and roosting sections of Cover requirements. In Ontario, ruffed grouse occur in all seral stages of aspen, birch, and spruce mixedwoods but prefers the early, stem exclusion stage of aspen- and/or birch- dominated or codominated stands [143]. Ruffed grouse generally select young stands in summer and mature stands in winter [183].
Early-successional hardwood habitats often support higher densities of ruffed grouse than older stages. In oak-hickory forests of Missouri, ruffed grouse density was positively correlated (P=0.02) with the percent occurrence of 7- to 15-year-old hardwood regeneration. All areas with low ruffed grouse densities (<3.3/100 ha) had less than 7% of the area in this age class [207]. Ruffed grouse occurred infrequently in an old-growth western hemlock-western redcedar forest in northern Idaho that was fragmented by 10- to 26-year-old clearcuts; they did not occur in more recently fragmented or unfragmented landscapes [81]. In northern Minnesota, the highest ruffed grouse densities, 210/ mile², were observed in hardwood stands 12 to 25 years old. Ruffed grouse occurred at densities of 106/mile² in 7-to 12-year-old hardwood stands and 70/mile² in 40- to 60-year-old hardwood stands. Ruffed grouse occurred at lower densities in hardwood stands from 60 to 80 years old. Maximum ruffed grouse densities in coniferous forests, 64/mile², occurred in stands from 7 to 15 years old [60]. In contrast, ruffed grouse in Algonquin Provincial Park in Ontario occurred at a density of 6 males/100 acres in pioneer birch-aspen woodlands as well as in later-successional fir-spruce forests and fir-spruce forests with hardwoods [132]. Similarly, ruffed grouse occurred in aspen stands of all ages in mixed conifer-aspen habitats in British Columbia. Densities were variable within age classes, with lowest densities occurring in aspen stands less than 6 years old and highest densities (12.74 ruffed grouse/25 acres) occurring in sapling aspen communities. Maximum densities in mature aspen and mixed conifer-aspen stands were 8.49 to 10.19 ruffed grouse/25 acres. Openings within mature aspen stands likely helped support relatively high ruffed grouse densities [146].
In northern Minnesota, ruffed grouse survived longer in intermediate-aged stands than in mature stands or those less than 7 years old. Average ruffed grouse survival time was 22.3 months in hardwood stands that were 12 to 25 years old and 19.2 months in hardwood stands that were 40 to 80 years old. Survival was lower in younger hardwood stands, with ruffed grouse in 7- to 12-year-old stands living an average of 11 months and those in stands less than 7 years old living less than 5 months. In conifer forests of this area, survival was highest in stands from 7 to 40 years old and in stands where spruce and fir had established but not yet become dominant. Ruffed grouse survived less than 5 months on average in conifer stands less than 7 years old and in stands from about 40 years old until the establishment of spruce and fir [60].
Early-successional habitat is selected by male and female grouse throughout the year, but it is used most often from spring to fall. In oak-hickory and eastern redcedar-hardwood forests in central Missouri [194], mixed-oak forests in North Carolina [102], a mosaic of several hardwood communities in southwest Virginia [46], and oak-hickory forests in Rhode Island [43], ruffed grouse home ranges included more early-successional stages than would be expected based on availability in the study areas (P<0.05). Early-successional forest was the most consistent habitat component for ruffed grouse in Rhode Island, even though it comprised less than 1% of the land area [13]. Ruffed grouse released into oak-hickory forest in Missouri in fall used early-successional forest from fall to spring 36% to 77% more than would be expected based on availability. Selection of early-successional forest was most strong in spring (P=0.009) [111]. In eastern redcedar-hardwood forests in central Missouri, 2- to 4-year-old clearcuts were selected in spring and summer (P<0.05) [194]. In quaking aspen-mixedwoods of Alberta, ruffed grouse abundance in late May and June was significantly (P<0.001) greater in 20- to 30-year-old quaking aspen-mixedwood forests than in stands that were 50 to 65 years old or those older than 120 years [161]. In North Carolina, male ruffed grouse selected 6- to 20-year-old forests in fall and winter [102]. In contrast, in winter in Ontario, females avoided 2- to 20-year-old stands and clearcuts from 2 to 10 years old [11].
Mature stands provide ruffed grouse foraging and breeding habitat [32]. Ruffed grouse in Alberta were characteristic of quaking aspen groves and quaking aspen parkland at least 60 years old and lodgepole pine/grass and lodgepole pine/moss (Bryophyta) communities over 125 years old [195]. In Minnesota, 61% of activity centers in uncut mature aspen that were occupied in 1961 were also occupied in 1966. Following a clearcut, only 4% of activity centers that occurred in 1961 were also occupied in 1966 [61]. In a Engelmann spruce-subalpine fir (Picea engelmannii-Abies lasiocarpa) forest of Yellowstone National Park, ruffed grouse were observed at a density of 8.9 pairs/40 hectares in an unburned mature stand at least 350 years old [145]. In winter in Ontario, female ruffed grouse selected 61- to 120-year-old stands and mature uncut stands (P<0.001) [11]. In North Carolina, female ruffed grouse selected late-rotation (>80 years) mixed oak in winter and mature (40-80 years) mesic hardwoods in spring and fall [102]. In southwestern Virginia, drumming ruffed grouse occurred only in a forest where most trees were from 110 to 180 years old. They did not occur in 1-, 3-, 7-, 12-, or 30-year-old clearcuts [23]. In Grand Teton National Park in Wyoming, the 0.01-acre (0.04 ha) area around drumming sites occurred in mature stands with large-diameter logs and snags of lodgepole pine and quaking aspen [20]. In western Washington, drumming ruffed grouse "seem to aggregate in mixed stands 40 to 50 years old" [158]. In contrast, ruffed grouse released into northern Missouri in fall used mature forest less than would be expected based on availability [111]. Habitat features characteristic of early-successional stands, such as an open canopy, were selected by ruffed grouse on a southeastern Idaho study; most quaking aspen stands were at least 60 years old [180].
Ruffed grouse are generally short-lived. Birds more than 5 years old were uncommon in New York (Bump and others 1947 cited in [24]). The longest recorded life span of a ruffed grouse in northern Minnesota was 7.8 years [65].
Annual survival rates of adult ruffed grouse typically range from 30% to 60% [156] and may be higher in the southern portions of the range [34]. Range-wide male survival averages about 34% [156]. Annual survival rates of males in northern Minnesota range from 11.1% [68] to 47% (Gullion and Marshall 1968 cited in [24]). Averaged across sites and years, annual survival of ruffed grouse in the Appalachian region was 42% and ranged from 17% to 57% [34]. In predominantly oak-hickory forests of central Missouri, annual survival of male ruffed grouse was 35% [194]. In a landscape with several communities including mixed oak and mixed hardwood in western North Carolina, mean annual survival of ruffed grouse was 39% [101]. For relationships between survival and habitat, see Plant associations used as habitat.
Juveniles likely have lower survival than adults. Although statistical significance varied across sites and years, adult survival was generally greater than that of juveniles in northern Michigan. On 3 of 4 sites, juveniles had significantly (P≤0.046) greater risk of mortality than adults [22]. Immature ruffed grouse survival did not differ significantly from adult survival in the Appalachian region, but models indicated adult survival may have been greater than that of juveniles in autumn or winter [34]. Reviews note low survival of chicks [24,156]. The table below provides survival rates of chicks in different locations and implies that survival of juveniles may be higher in northern than southern portions of ruffed grouse range. See Plant associations used as habitat for more detail regarding this trend and Forage quality for further details.
Table 1. Survival of ruffed grouse chicks for various periods in different portions of their range Location Time Period Chick survival Northern Michigan Just after hatching to dispersalRuffed grouse survival was greater in summer than other seasons in predominantly oak-hickory forests of central Missouri [194], in a landscape with several communities including mixed oak and mixed hardwood in western North Carolina [101], and pooled over 12 sites in the Appalachian region [34].
Ruffed grouse survival may be lower in winter, especially for the red-phased ruffed grouse, which occur throughout the species’ range but is most common in southern regions [61,156] and coastal areas of the Pacific Northwest [156]. In northern Minnesota, red-phased ruffed grouse had shorter life expectancy than gray-phased roughed grouse, and the difference was especially prevalent in winters with sparse snow cover. The ratio of red-phased to gray-phased birds declined substantially from fall to spring during winters with little snow cover, while ratios of red to gray-phase birds were similar in fall and spring during winters with greater snow cover. Warmer weather as well as the colorful foliage of northern hardwoods were suggested as explanations for greater occurrence of red-phased individuals in more southerly locations [61]. In some years, winter weather variables such as days of crusted snow or average minimum monthly temperature were associated with ruffed grouse survival in the Appalachian region [34]. See Winter roosting for details on the importance of winter roost sites for ruffed grouse.
There is limited evidence that movement is associated with increased mortality, perhaps more so in unfamiliar environments. In Missouri, lower male ruffed grouse survival in fall and winter coincided with significantly (P=0.033) greater daily movement distances in fall and winter (1,286 feet (392 m)/ day) than in spring and summer (863 feet (263 m)/ day). Ruffed grouse survival was inversely related to distance moved (Kurzejeski and Root 1988 cited in [194]). In southeastern and eastern Ohio, increased movement rates were associated with increased predation risk. However, of 6 movement rates investigated only the distance moved by adults per 3-day period was significantly (P=0.0385) associated with predation. The risk of predation was 3 to 7.5 times greater in unfamiliar than in familiar areas (0.0002≤P≤0.0452) [211]. In central Wisconsin, autumn to spring juvenile survival was similar between the early dispersal period, when ruffed grouse were moving extensively, and the later dispersal period, when individuals had settled in an area [172].
Other survival trends have been reported from various geographic regions: In southwest Alberta, ruffed grouse tend to survive better on consistently used territories compared on intermittently used territories [14]. In boreal forests, ruffed grouse survival was lower when the birds used a drumming log that had been used the previous breeding season [65]. In western North Carolina, a negative relationship occurred between survival and population density, perhaps related to habitat availability [101].
In the northern portions of the ruffed grouse's range, aspen buds and catkins are critical components of the diet during the late fall [24,29,63], winter [24,29,63,84,156,186,188,192], and spring [63,124,186]. In addition to providing good quality nutrition, aspen buds are easier to obtain than buds of species such as eastern hophornbeam (Ostrya virginiana) or birch (Betula spp.) [188] (see Forage quality). In Minnesota, ruffed grouse selected quaking aspen over paper birch (B. papyrifera) (P<0.01) in winter [188], and its flower buds and catkins were typically the most important food item from mid-October to early May [63]. In northern Utah, quaking aspen buds comprised the largest proportion of the diet, indicated by occurrence in an average of 41% of ruffed grouse feces [84]. Before the start of the breeding season, aspen flower buds comprised 46% of crop contents of ruffed grouse in aspen-dominated forests of Michigan, Wisconsin, and Minnesota [124]. Quaking and bigtooth aspen buds, twigs, and catkins were used most heavily during winter and spring on a study site in Ohio [186]. Quaking aspen leaves were an important component of the fall diet of ruffed grouse in western quaking aspen communities [29]. Although aspen is a critical food source, Clark [22] suggests that the model used to assess habitat suitability for Michigan (Hammill and Moran 1986 cited in [22]) overemphasizes the importance of mature aspen as a food source.
Ruffed grouse typically eat buds, catkins, and/or twigs of other tree species, such as willow (Salix spp.) [24,29,84,156], birch [24,192], eastern hophornbeam [24,108], hazelnut (Corylus spp.) [24,39,108], and cherry (Prunus spp.) [24,186] in winter and spring. In Ohio, ruffed grouse used buds, twigs, and/or catkins of black cherry (P. serotina), dogwoods (Cornus spp.), eastern hophornbeam, and hawthorns (Crataegus spp.) during winter and spring [186]. Buds and catkins of eastern hophornbeam were considered an important ruffed grouse winter food by Leak and Bonner [120]. In winter in Wisconsin, ruffed grouse in a northern hardwoods community most commonly ate catkins of eastern hophornbeam and yellow birch (B. alleghaniensis). Ruffed grouse in an aspen community commonly ate birch buds; paper birch, cherry, and hazelnut twig tips; and paper birch and hazelnut catkins [39]. In fall, ruffed grouse ate buds and catkins of hazelnut in the northern mixed-forest region. In winter, birch buds and catkins and cherry buds are important food sources for ruffed grouse in northern mixed forests, and hazelnut catkins and buds and twigs of willow are important in the boreal region. In spring, ruffed grouse ate eastern hophornbeam buds and catkins in Missouri and birch buds and catkins in northern mixed forests [24].
Herbaceous material comprises much of the ruffed grouse's diet, especially in spring and summer [124,140,156,186] and during winter in the central [186] and southern [156,167,178] portions of the ruffed grouse's range. In spring before the start of breeding, herbaceous and evergreen leaves were prevalent components in the diets of ruffed grouse in the Appalachian region [124]. Herbaceous material was the principal food in the spring and summer diet of ruffed grouse from southwestern Virginia [140]. On an Ohio study site, herbaceous material such as leaves of ferns (Pteridophyta), bedstraws (Galium spp.), and grasses (Poaceae) occurred in 65% of samples during all seasons [186]. In eastern Tennessee and western North Carolina, herbaceous material from species on the forest floor and leaves of vines and woody shrubs comprised 63% of the food consumed in winter [178].
Hard mast, such as oak acorns and beech (Fagus spp.) nuts, is used in the fall and winter and is especially important for ruffed grouse in the Central Hardwoods [151,192] and southern [34,124] regions of the ruffed grouse's range. Because of oak mast importance in fall and winter diets and its limited supply, the habitat suitability index for ruffed grouse in the Central Hardwoods region includes acorn production as a factor determining habitat quality [151]. In southeastern Virginia, hard mast comprised a substantial amount of the fall diet [140]. In Missouri, acorns were eaten from fall to spring, with a peak in October [108]. In the Appalachian region, oak mast was an important component of the diet before the start of the breeding season [124]. For a more detailed description of the importance of hard mast to ruffed grouse in the southern portions of its range, see Forage quality.
Soft mast is used most extensively in the summer and fall and may comprise a larger proportion of winter diets in the Central Hardwoods [192] and southern regions [140,167] than more northern portions of the ruffed grouse's range. Fruits of many species, including grapes (Vitis spp.), dogwoods, greenbriers (Smilax spp.), hawthorns, sumacs (Rhus spp.), roses (Rosa spp.), blackberries (Rubus spp.), and blueberries (Vaccinium spp.) were used most extensively in summer and fall, and they were frequent components of winter and spring diets of ruffed grouse on a site in Ohio [186]. In southeastern Virginia, soft fruits such as those of greenbriers, grapes, viburnums (Viburnum spp.), dogwoods, and roses comprised substantial proportions of ruffed grouse crop contents from spring to fall [140]. Soft mast species eaten in the Central Hardwoods region in fall and winter include hawthorns, viburnums, dogwoods, and cherries [192]. In October, ruffed grouse in interior Alaska switch from eating soft fruits to eating quaking aspen and willow buds [156].
Seeds may be important to ruffed grouse in the summer and fall. Seeds used include those of sedges (Cyperaceae) [24,108], panicgrasses (Panicum spp.) [153], tick trefoils (Desmodium spp.) [24], salal (Gaultheria shallon) [91], and various shrubs [93]. Sedge seeds comprised a substantial portion of the ruffed grouse diet in June in Missouri [108] and in summer in Idaho [93]. In the late summer, panicgrass seeds became a prominent component of the diet of ruffed grouse chicks from 8 to 10 weeks old in oak-hickory forests of West Virginia [153]. Hemlock (Tsuga spp.) seeds were reportedly important in the nonbreeding season in eastern North America (Yamasaki and others 2000 cited in [18]). Seeds and fruits were used most heavily in the summer and fall but were commonly used in winter on an Ohio study site [186].
Males drum and establish their first territories from about 6 months to 1.5 years of age. All adult males (≥1 year old) in Alberta, Wisconsin, and Minnesota were territorial and drummed, while about half of males less than 1 year old drummed [156]. Typically, breeding males drum in territories established in the winter or spring [24]. During the breeding season, about 66% of males defend territories, which typically average over 5 acres (2 ha) [156] and may be as large as 11.1 acres (4.4 ha) [24].
Males exhibit high territory fidelity. In Minnesota only 12% of males occupied territories more than 330 feet (100 m) from their previous territory (Gullion and Marshall 1968 cited in [156]). In Alberta 93.5% of males' territories shifted less than 660 feet (200 m) from 1 year to the next, and the remainder shifted less than 1,310 feet (400 m). Of 60 males shot or captured in fall, only 1 was farther than 2,630 feet (800 m) from his breeding site (Rusch and Keith 1971b cited in [156]).
The ruffed grouse (Bonasa umbellus) is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is the most widely distributed game bird in North America.[2] It is non-migratory. It is the only species in the genus Bonasa.
The ruffed grouse is sometimes incorrectly referred to as a "partridge", an unrelated phasianid, and occasionally confused with the grey partridge, a bird of open areas rather than woodlands.[3]
The ruffed grouse is the state game bird of Pennsylvania, United States.[4]
Bonasa umbellus was first described by Carl Linnaeus in his 1766 12th edition of Systema Naturae.[5] He classified it as Tetrao umbellus, placing it in a subfamily with Eurasian grouse. The genus Bonasa was applied by British naturalist John Francis Stephens in 1819.[6] Ruffed grouse is the preferred common name because it applies only to this species. Misleading vernacular names abound, however, and it is often called partridge (sometimes rendered pa'tridge, or shortened to pat),[7] pheasant, or prairie chicken, all of which are properly applied to other birds.[8] Other nicknames for ruffed grouse include drummer or thunder-chicken.[9]
The ruffed grouse has 13 recognized subspecies:[10]
Ruffed grouse are chunky, medium-sized birds that weigh from 450–750 g (0.99–1.65 lb), measure from 40 to 50 cm (16 to 20 in) in length and span 50–64 cm (20–25 in) across their short, strong wings.[11] They have two distinct morphs: grey and brown. In the grey morph, the head, neck, and back are grey-brown; the breast is light with barring. There is much white on the underside and flanks. Overall, the birds have a variegated appearance; the throat is often distinctly lighter. The tail is essentially the same brownish grey, with regular barring and a broad black band near the end ("subterminal"). Brown-morph birds have tails of the same color and pattern. However, the rest of the plumage is much more brown, giving the appearance of a more uniform bird with less light plumage below and a conspicuously grey tail. There are all sorts of intergrades between the most typical morphs; warmer and more humid conditions favor browner birds in general.
The ruffs are on the sides of the neck in both sexes. They also have a crest on top of their head, which sometimes lies flat. Both sexes are similarly marked and sized, making them difficult to tell apart, even in hand. The female often has a broken subterminal tail band. At the same time, males tend to have unbroken tail bands, though the opposite of either can occur. Females may also do a display similar to the male. Another fairly accurate sign is that rump feathers with a single white dot indicate a female; rump feathers with more than one white dot indicate a male.
The average life span of a ruffed grouse is one year, although some birds are thought to live for as long as eleven years.[12][13] Ruffed grouse are polygynous, and males may mate with several females during the breeding season.
Like most grouse, they spend most of their time on the ground; mixed woodland rich in aspen seems to be particularly well-liked. These birds forage on the ground or in trees. They are omnivores, eating buds, leaves, berries, seeds, and insects. According to nature writer Don L. Johnson:
More than any other characteristic, it is the ruffed grouse's ability to thrive on a wide range of foods that has allowed it to adapt to such a wide and varied range of habitat on this continent. A complete menu of grouse fare might itself fill a book. One grouse crop yielded a live salamander in a salad of watercress. Another contained a small snake.[14]
Hunting of the ruffed grouse is common in the northern and far western United States as well as Canada, often with shotguns. Dogs may also be used. Hunting of the ruffed grouse can be challenging. This is because the grouse spends most of its time in thick brush, aspen stands, and second growth pines. It is also very hard to detect a foraging grouse bobbing about in the thicket due to their camouflage. With adequate snow cover, they will burrow under the snow. The ruffed grouse will maintain trails through the underbrush and pines like other forest creatures. These can often be found by looking for the bird's feathers on the ground and twigs at the edges of its trail. Hunting of the ruffed grouse requires a good ear and lots of stamina as one will be constantly walking and listening for them in the leaves.[15]
— Joseph B. Barney
Ruffed grouse frequently seek gravel and clover along road beds during early morning and late afternoon. These are good areas to walk during this time to flush birds. Also, grouse use sandy roadbeds to dust their feathers to rid themselves of skin pests. Dusting sites are visible as areas of disturbed soils with some signs of feathers. Birds will return to these spots during the late afternoon to bathe in dust and socialize and mate.
Minnesota is the top ruffed grouse–producing state in the U.S.[16]
The ruffed grouse differs from other grouse species in its courtship display. The ruffed grouse relies entirely on a non-vocal acoustic display, known as drumming, unlike other grouse species. The drumming itself is a rapid, wing-beating display that creates a low-frequency sound, starting slow and speeding up (thump ... thump ... thump..thump-thump-thump-thump). Even in thick woods, this can be heard for .25 miles (0.40 km) or more.
The ruffed grouse spends most of its time quietly on the ground, and when surprised, may explode into flight, beating its wings very loudly. They will burrow into the snow for warmth in the winter and may suddenly burst out of the snow when approached too closely.
The male grouse proclaims his property by engaging in a “drumming” display. This sound is made by beating his wings against the air to create a vacuum.[17] It usually stands on a log, stone or mound of dirt when drumming. It does not strike the log to make the noise, it only uses the “drumming log” as a sort of stage.[18]
The ruffed grouse population has a cycle, and follows the cycle no matter how much or how little hunting there is. The cycle has puzzled scientists for years, and is simply referred to as the "grouse cycle".[19][20][21][22][23][24][25] In spite of this historical cycle, populations have been declining in Pennsylvania and management plans adopted.[26][27] Habitat loss has been a concern for the species,[28][29][30] but the introduction of the West Nile virus has been seen to be further increasing mortality.[26][27][31][32][33][29]
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{{cite journal}}: Cite journal requires |journal= (help) A male found at the Kortright Center for Conservation. The ruffed grouse (Bonasa umbellus) is a medium-sized grouse occurring in forests from the Appalachian Mountains across Canada to Alaska. It is the most widely distributed game bird in North America. It is non-migratory. It is the only species in the genus Bonasa.
The ruffed grouse is sometimes incorrectly referred to as a "partridge", an unrelated phasianid, and occasionally confused with the grey partridge, a bird of open areas rather than woodlands.
The ruffed grouse is the state game bird of Pennsylvania, United States.
