The ruffed grouse (Bonasa umbellus) is a medium-sized grouse found in forests across North America, from the Appalachian Mountains to Alaska. As the most widely distributed game bird in North America, it has adapted to a variety of habitats and food sources. This article explores the ruffed grouse's diet and habitat, as well as current conservation efforts.
Description and Identification
Ruffed grouse are chunky, medium-sized birds, measuring 16-19 inches (41-48 cm) in length and weighing 450-750 g (0.99-1.65 lb). Their wingspan ranges from 20-25 inches (50-64 cm). These birds have a slight crest and a long, fan-shaped tail with a wide blackish band near the tip. A key feature is the black 'ruffs' on the sides of their neck, which are more apparent during displays. Wide bars of dark and white on their sides may also be conspicuous.
Ruffed grouse exhibit two distinct color morphs: grey and brown. Grey-morph birds have a grey-brown head, neck, and back, with a light, barred breast and considerable white on the underside and flanks. Brown-morph birds have more brown plumage, creating a more uniform appearance, but their tails remain the same color and pattern as the grey morph.
Sexes are similar in size and markings, making them difficult to distinguish. However, females often have a broken subterminal tail band, while males tend to have unbroken tail bands.
Habitat Preferences
Ruffed grouse thrive in deciduous and mixed forests, particularly those with scattered clearings and dense undergrowth. Overgrown pastures also provide suitable habitat. Mixed-age groves of aspen, spruce, and birch are ideal in the northern part of their range. Further south, they inhabit deciduous forests of oaks, hickories, and pines. In the Pacific Northwest, they can be found in riparian habitats.
Read also: The Hoxsey Diet
Young stands of trees are crucial for both cover and food, leading to higher grouse populations in areas with logging, burning, and other disturbances that create early-successional forests. Mature forests and small patches of woods surrounded by agricultural lands typically have lower populations.
Diet and Foraging Behavior
Ruffed grouse are omnivores, foraging on the ground or in trees. Their diet includes buds, leaves, berries, seeds, and insects. According to nature writer Don L. Johnson, their ability to thrive on a wide range of foods has allowed them to adapt to a varied range of habitats.
In the fall, soft fruits and acorns become an important part of their diet. During winter, when snow covers the ground, they primarily eat the dormant flower buds or catkins of aspens, birches, and cherries. Aspen is considered the most important year-round food source in Maine. Ruffed Grouse's ability to digest foods high in cellulose make it possible for them to survive harsh winter conditions in the northern part of their range, where they feed on buds and twigs of aspen, birch, and willow. In winter, birds in the south forage on leaves and fruit of greenbrier, mountain laurel, Christmas fern, and other green plants. Although insects and other invertebrates make up only a small part of the adult grouse’s diet, chicks 2 to 4 weeks old depend on this protein-rich prey.
In the Southern Appalachians, ruffed grouse diets differ from those in Northern forests. Summer diets consist of herbaceous plants, with chicks primarily eating insects during their first weeks. Blueberries and blackberries are also important summer food sources. Winter diets are more limited, with evergreen leaves like mountain laurel making up a significant portion of their intake. Oak acorns and beechnuts are also a substantial part of their diet, reflecting the dominance of oak, hickory, and mixed hardwood forests in the region.
Ruffed grouse frequently seek gravel and clover along roadbeds during early morning and late afternoon, and use sandy roadbeds to dust their feathers to rid themselves of skin pests.
Read also: Walnut Keto Guide
Nesting and Reproduction
After mating, female Ruffed Grouse choose a nest site at the base of a tree, stump, or rock in areas with sparse ground cover that give a clear view of predators. Nests may also be built in brush piles, or in the bases of partially open, hollowed-out stumps.
The Ruffed Grouse’s nest is a simple, hollowed-out depression in leaves on the forest floor, reaching up to 6 inches across and 3 inches deep. Females build the bowl-shaped nest and typically line the bowl with vegetation that they pluck from the edge of the nest site.
The clutch normally numbers 9 - 14 eggs, which are laid over a period of approximately 2 weeks. The eggs are incubated about 24 days, and all the eggs hatch within a few hours of each other during late May and early June. Young ruffed grouse are precocial (able to move about shortly after hatching), therefore they are capable of moving to brood range (forest openings created by fire, logging, etc.) after only 3 or 4 days. Both eggs and brood are vulnerable to predation by foxes, weasels, skunks, raccoons, hawks, owls, and other predators, including dogs and cats. The hen will try to protect the eggs and young by feigning injury ("broken wing act") or bluffing to draw the predator away. Over a third of the nests may be broken up before the eggs hatched.
Behavior and Social Structure
Ruffed grouse spend most of their time on the ground and are difficult to spot due to their cryptic coloration and slow movements. When surprised, they may explode into flight with a loud flapping of wings. In the winter time, they burrow into about a foot of soft fluffy snow. This helps them evade predation and better thermal regulate their body. When they have good burrowing snow, they use less energy and have better survivability.
The male grouse proclaims his territory by engaging in a nonvocal, acoustic display known as drumming. This sound is made by beating his wings against the air to create a vacuum. It usually stands on a log, stone, or mound of soil when drumming.
Read also: Weight Loss with Low-FODMAP
Although Ruffed Grouse are normally solitary, small groups of unrelated birds may form in fall or winter to take advantage of productive feeding spots.
Population Dynamics and Conservation
Ruffed grouse populations are known to follow a cycle, regardless of hunting pressure. Populations of Ruffed Grouse are lower in mature forests and in small patches of woods surrounded by agricultural lands.
Ruffed Grouse are fairly common and widespread, and their populations have held steady between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 18 million and rates them 8 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. The grouse’s immense popularity as a game bird has led to controls on season length, bag limits, and area closures, as well as to extensive efforts to improve habitat through management practices that encourage early successional forest. The Ruffed Grouse Society partners with government agencies in programs to expand grouse habitat through land purchases and targeted management. Habitat for Ruffed Grouse has declined where forests have matured due to fire control and limits on logging.
However, there have been some concerns with the ruffed grouse population going back to 2017-18. There was a sudden population decline at a time when we thought the population would be going up. There were also lot of other concerns like the 2017-18 heavy spring weather events that could have caused localized impacts at a very unfortunate time when a lot of ruffed grouse were either nesting or young broods were just hatching and could have been drowned out. There could have also been some synergistic effects with Eastern Equine Encephalitis, which is a native bird disease we’ve known about since the 1950s. What is concerning about diseases like West Nile Virus and Eastern Equine Encephalitis in the context of climate change, is that the upper Great Lakes Region is predicted to get wetter under current climate models.
In the Southern Appalachians, ruffed grouse populations have declined by 71% since 1989, with only 1.3% of National Forest lands consisting of young forests.
Hunting
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.