Bonasa
umbellus
(Ruffed
Grouse)
Physical
Description:
16-19" (40-48 cm). Two
color phases. Red phase: mottled rufous
above, lighter and barred
below; tail red, finely barred, with broad, dark subterminal band and light
tip. Gray phase: gray replaces red
and rufous. Both phases show a slight crest, a fan-shaped tail, and black feathers
on sides of neck.
Similar Species- Female Spruce Grouse, Sharp-tailed Grouse
Song:
Male
beats wings on logs in an accelerating drum roll. May sound like a distant motor
starting up.
Distribution:
Central
Alaska and most of forested Canada, south to northern California, central Arizona,
central Idaho, central Utah, western South Dakota, Minnesota, Georgia, and Virginia.
Habitat:
Found in wet or relatively dry, dense
forests with some deciduous trees, such as boreal forests (especially early
seral stages dominated by aspen) or northern hardwood ecotone. In southeastern Idaho
study, Ruffed Grouse were associated with early-successional aspen stands year-round.
Diet:
Young eat mainly insects and spiders. Adults eat insects (30% of summer diet), nuts, flowers, buds, and leaves of trees and shrubs, seeds, and fruits. In many areas, aspen, willow, and rose family are important food resources.
Ecology:
Nests in depression on ground. Usually
roosts in small groups in winter.
Population densities may fluctuate (10- yr cycle in some populations). Spring
density may reach 2-10/40 ha;
fall density 20-55/ha (highest in boreal forest regions). brood home range is about 6-19
ha. In Missouri study, mean adult male home range was 67 ha in spring-summer,
104 ha in fall-winter. Mature and some immature males may defend a territory.
Predators include Great-horned Owl and Northern Goshawk. Shallow snow cover
or icy crust on snow may reduce winter survival by precluding access to subnivean shelter.
4-19 eggs (generally 9-12)
for 23-24 days. Nestlings are precocial and downy, and fly in
10-12 days. Young are tended by female. broods break up in fall when
young are about 84 days old (young disperse at about 120-125 days in Wisconsin).
Single-brooded, but females may renest if first nesting attempt is unsuccessful.
Sexually mature in 1 yr; uncommonly lives more than 5 yr. Cold, wet weather in
May/June may cause high losses among broods.
Conservation:
| Element Code: | ABNLC11010 |
| Status: | Game species |
| Global Rank: | G5 |
| State Rank: | S5 |
| National Rank: | N5 |
Important State References:
Stauffer, D.F. and S.R. Peterson. 1985.
Ruffed and blue grouse habitat use in southeastern Idaho. J. Wildl. Manage.
49:459-466.