Species: Bonasa umbellus

Ruffed Grouse

Species

Birds

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Terrestrial vertebrates: birds

Encyclopedia of Puget Sound

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Aves

Order

Galliformes

Family

Phasianidae

Genus

Bonasa

NatureServe

Source:
ELEMENT_GLOBAL.2.102687

Classification

Other Global Common Names

gélinotte huppée

Informal Taxonomy

Animals, Vertebrates - Birds - Other Birds

Formal Taxonomy

Animalia - Craniata - Aves - Galliformes - Phasianidae - Bonasa - (capercaillie, a European grouse).

Ecology and Life History

Migration

true - false - false

Non-migrant

true

Locally Migrant

false

Food Comments

Young eat mainly insects and spiders. During summer insects may comprise about 30% of diet of adults. Adults also eat many herbaceous plants (especially in spring and summer), seeds, fruits (especially in fall and winter), nuts, flowers, buds, and leaves of trees and shrubs. In many areas, aspen (in boreal region, especially staminate buds and catkins), willow, and/or Rosaceae, or birch, alder, and hazelnut buds and catkins, are important food resources in winter and spring. See Crawford (1986) for further details.

Reproduction Comments

Drumming and mating peak in mid-March in Missouri, early April in Indiana, and late April in Minnesota, early May in far north. The first eggs are laid in April or May, depending on the location (latitude). Clutch size is 4-19 (generally 9-12). Incubation, by female, lasts 23-24 days. Nestlings are precocial, downy; can fly in 10-12 days. Young are tended by female. Broods break up in fall when young about 84 days old; young disperse (Terres 1980), at about 120-125 days in Wisconsin (Small and Rusch 1989). In Alberta, about 50% of young survived from fall to spring (Rusch and Keith 1971). Single-brooded, but females may renest of first nesting attempt is unsuccessful. Sexually mature in one year; uncommonly lives more than 5 years. Cold wet weather in May/June may cause high losses among broods.

Ecology Comments

Population densities may fluctuate dramatically. Some populations exhibit an approximately 10-year cycle of abundance. Spring density generally about 2-10/40ha; fall density up to 20-55/ha; densities highest in boreal forest region (Crawford 1986). Good habitats support densities better than 1 breeding male per 8 ha (Atwater and Schnell 1989). Home range of brood about 6-19 ha, averages about 16 ha (40 acres). In Missouri, mean home range of adult males was 104 ha in fall-winter, 67 ha in spring-summer (Thompson and Fritzell 1989); Crawford 1986 reported examples of male and female home ranges that ranged from 2-12 ha. Mature and some immature males may defend a territory. In Wisconsin, juvenile females in fall dispersed average of 4.8 km to winter range, males 2.1 km; in other areas dispersal distance often less than 2 km; juvenile males may wander extensively in spring (Small and Rusch 1989). Usually roosts in small groups in winter. Fox predation often is an important cause of nesting failure. Other important predators include great horned owl and, in north, goshawk. In Alberta, predation by great horned owl declined when snowshoe hares were abundant (Rusch and Keith 1971). Shallow snow cover or icy crust on snow may reduce survival in winter by precluding access to subnivean shelter.

Length

Weight

621

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1996-11-25

Global Status Last Changed

1996-11-25

Other Status

LC - Least concern

Distribution

Conservation Status Map

Global Range

RESIDENT: central Alaska and most of forested Canada south to northern California, central Idaho, central Utah, western South Dakota, Minnesota, central Arkansas, northern Georgia, and northeastern Virginia; introduced and established in Iowa, Newfoundland, Nevada, and part of Michigan (Godfrey 1966, AOU 1983, Crawford 1986). See Crawford (1986) for a map of distribution by subspecies. Was virtually extirpated from Indiana, Missouri, and Illinois, and populations were greatly reduced in Kentucky, Ohio, Tennessee, and parts of Montana, Saskatchewan, and Alberta. Reintroduced into Missouri and Indiana. Populations are limited in Illinois, Missouri, Nevada, and South Dakota.

ELEMENT_GLOBAL.2.102687