Winter use of douglas-fir forests by Blue Grouse in Colorado

We studied winter use of Douglas-fir (Pseudotsuga menziesii) forests by blue grouse (Dendragapus obscurus) from 1981 to 1983 at 2 study areas in northcentral Colorado. Comparisons of used and available stands indicated grouse were concentrated spatially, but there were no consistent differences related to basal area of tree species, conifer stem densities, and topography that were common to both areas. Blue grouse used dense (2,000 stems/ha) second growth (40-75 yr old), open to dense (200-1,900 stems/ha) mature (100-200 yr old), and open (