(Montana State University - Bozeman, College of Letters & Science, 2006) Sika, Jenny Lyn; Chairperson, Graduate Committee: Jay J. Rotella
Declines in productivity have been implicated in population declines for greater sage-grouse (Centrocercus urophasianus) in several areas, but there is considerable variation in reproductive effort, reproductive success and female survival, both temporally and spatially, and more data are needed. Despite declining populations, sage grouse are still legally harvested in most of their current range, including Montana, and uncertainty about how harvest impacts sage grouse vital rates remains. The reproductive activity, survival rates, and causes of mortality of hunted and nonhunted sage grouse females were monitored year round using radio-telemetry in central Montana during 2004 and 2005. Data on nest survival and brood survival were also collected. Nest survival was greater for renests, 0.56, than for first nests, 0.32. Brood survival to 30 days posthatch was estimated as 0.79. Reproductive effort and reproductive success were higher in 2005. Female survival during the nesting season was constant, 0.94 monthly.
