Field observations over a two-year period (1938-1940) were made in the Boise National Forest on the cover preferences, seasonal movements, and food habits of Richardson's Grouse (Dendragapus obscurus richardsoni) and the Idaho Ruffed Grouse (Bonasa umbellus phaios). From October through March, Richardson's Grouse lived on the higher ridges, where they were dependent on scattered stands of conifers for both food and cover. In May, June, and early July, they stayed at lower elevations and ate chiefly the flowering parts of various plants. In late July and early August, broods and females were concentrated along water courses, while single birds (those identified proving to be adult males) were in the higher timber types. The food at this time consisted largely of insects, berries, fruits, and leaves of various shrubs. By mid-September the females and broods had moved to the higher ridges, where at first they continued to feed on berries and leaves of shrubs and later shifted to a diet of conifer needles and buds. Idaho Ruffed Grouse were found in the overmature ponderosa pine and Douglas fir-spruce types at middle elevations throughout the year. During the winter they fed largely on the buds of a wide variety of shrubs which grow under openings in the forest canopy. The movements of this grouse are apparently quite restricted. Both species of grouse were dependent during the entire year on coniferous trees for escape cover. The movements of the Richardson's Grouse seem to be influenced by the differing rates of plant development at different altitudes. The summer range of the Richardson's Grouse is in areas intensively used by man and livestock, but the winter range is in areas relatively unaffected by man. Although some lumbering is carried on in the range of the Ruffed Grouse, it does not seriously endanger the grouse habitat. Grouse hunting has decreased in recent years. Brood counts along water courses in August furnish a dependable basis for estimates of yearly population increase. Continued improvements in range management practices on the spring and summer ranges and the use of a flexible September hunting season based on August brood counts should be adequate to build up the grouse populations of the area.
引证/输出
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