AVAILABILITY OF FOODS OF SAGE GROUSE CHICKS FOLLOWING PRESCRIBED FIREIN SAGEBRUSH-BITTERBRUSH

A study was conducted to determine the influence of prescribed fire on the availability of primary foods of sage grouse (Centrocercus uropha sianus Bonaparte) chicks at Hart Mountain National Antelope Refuge, La ke County, Ore, from 1987 to 1989. Responses of certain primary foods and general food categories to fire were evaluated in sagebrush (Artem isia tridentata ssp. vaseyana Beetle)-bitterbrush (Purshia tridentata Pursh.) communities with a randomized block design established in stan ds where shrub cover exceeded 35%. Within blocks, habitat response was evaluated far 2 growing seasons on 4 plots used as controls, 3 plots burned in November 1987, and 4 plots burned in March 1988. Fall burnin g increased (P < 0.05) frequency of taxa in the dandelion tribe (Cicho riene). Other primary foods, including microsteris (Microsteris gracil is Hook.), desert-parsley (Lomatium spp. Raf.), and ground-dwelling be etles (Scarabaeidae, Tenebrionidae) were not influenced by burning. Sp ring and fall burning increased (P < 0.05) total forb cover and divers ity, but decreased (P < 0.05) sagebrush cover. Prescribed fire may inc rease the supply of forbs available to sage grouse in montane sagebrus h habitats used for brood-rearing where shrubs dominate stands at the expense of the herbaceous component.