Sage Grouse Movements in Southwestern Montana

Abstract

Sage grouse (Centrocercus urophasianas) populations have declined throughout the western United States and in southwestern Montana since the 1970s. Conservation efforts rely on knowledge of seasonal habitat distribution and sage grouse movement patterns between these habitats. Both of these factors are poorly understood and undocumented in southwestern Montana. An ongoing, cooperative study was initiated in 1999 to radio-track sage grouse in southwestern Montana to identify resident and migratory populations, key habitats, and movement patterns relevant to local sagebrush and sage grouse conservation. Thirty-seven sage grouse were fitted with radio transmitters and monitored ≤ 24 months in Horse Prairie, Sweetwater Basin, and Big Sheep Creek Basin in Beaverhead and Madison Counties near Dillon, Montana. Data collection included aerial monitoring supplemented with ground relocations obtained between flights. Results indicated that some groups of sage grouse were resident within a particular habitat complex while others traveled greater distances to utilize suitable breeding, summer, and winter habitat. This study helped identify locally important brood-rearing and summer habitats. Annual mortality of radio-tracked birds has averaged 58 percent over 3 years, with 50-83 percent losses for males (n = 20) and 14-50 percent losses for females (n = 4).