Sage Grouse Response to Pinyon-Juniper Management

The response of Gunnison sage grouse (Centrocercus minimus) to management of pinyon-juniper (Pinus edulis - Juniperus spp.) was studied in southwestern Colorado during 1994 through 1997. Near Crawford, CO, numbers of male sage grouse using leks within 100 m of live pinyon-juniper were de­ pressed because of increased raptor presence and predation asso­ ciated with coniferous trees/shrubs. Removal, by cutting, of pin­ yon-juniper trees/shrubs in association with brush-beating to reduce height of mountain big sagebrush and deciduous brush resulted in doubling numbers of male sage grouse counted on treatment leks in years 2 and 3 posttreatment. Clearing of young age classes of pinyon-juniper that have spread into sagebrush shrub-steppe appears to have great merit for enhancing sage grouse use of treated areas through increased s"urvival, productiv­ ity, and recruitment. This is especially significant in management of small populations of sage grouse in highly fragmented habitats which may be locally threatened with extirpation. Sage grouse (Centrocercus spp.) are dependent upon sagebrush (Artemisia spp.) shrub- steppe throughout their distribution in western North America (Patterson 1952). While exact composition of the original sagebrush shrub­ steppe is unknown, both grazing by wild ungulates and fire commonly occurred, especially in higher preci pi tation zones. Grazing of this habitat type increased following settlement resulting in more bare mineral soil. At the same time, fire frequency has generally decreased although intensity has increased in some areas (Bunting 1994). Primarily because of these 2 factors, seedlings of pinyon pine (Pinus spp.) and juniper (Juniperus spp.) have become established in sage­ brush-dominated lands in the last 40-60 years. Populations of sage grouse have declined in many areas of their former range (Connelly and Braun 1997). These declines are most notable where population size is con­ strained by habitat limitations including loss, fragmenta­ tion, and degradation of sagebrush-dominated ecosystems. Extinctions of local populations of sage grouse have oc­ curred, especially at the periphery of the original distribu­ tion (Johnsgard 1973, Braun 1995).