Managing Multiple Vital Rates To Maximize Greater Sage Grouse Population Growth

Scientific Disciplines
Biological Sciences - Terrestrial
Keywords
survival
University of Montana
sage grouse
sensitivity analyses
Years
Authors
Volumes
Volume 17, No. 1-4

Managing multiple vital rates to maximize greater sage 
Grouse population growth  
Rebecca L. Taylor,* Wildlife Biology Program, College of Forestry and Conservation, University 
of Montana, 32 Campus Drive, Missoula, Montana 59812.
Brett L. Walker, Colorado Division of Wildlife, 711 Independent Avenue, Grand Junction, Colorado 
81505
David E. Naugle, Wildlife Biology Program, College of Forestry and Conservation, University of 
Montana, 32 Campus Drive, Missoula, Montana 59812
L. Scott Mills, Wildlife Biology Program, College of Forestry and Conservation, University of 
Montana, 32 Campus Drive, Missoula, Montana 59812
Despite decades of greater sage grouse (Centrocercus urophasianus) field research, the 
resulting range-wide demographic data has yet to be synthesized into sensitivity analyses to 
guide management actions. We summarized range-wide demographic rates from 71 studies 


from 1938-2008 to better understand greater sage-grouse population dynamics. We used 
data from 38 of these studies with suitable data to parameterize a two-stage, female-based 
population matrix model. We conducted analytical sensitivity, elasticity, and variance-
stabilized sensitivity analyses to identify the contribution of each vital rate to population 
growth rate (λ) and life-stage simulation analysis (LSA) to determine the proportion of 
variation in λ accounted for by each vital rate. Greater sage grouse showed marked annual 
and geographic variation in multiple vital rates. Sensitivity analyses suggest that, in contrast 
to most other North American galliforms, female survival is as important for population 
growth as chick survival and more important than nest success. In lieu of quantitative data 
on factors driving local populations, we recommend that management efforts for sage grouse 
focus on increasing juvenile, yearling, and adult female survival by restoring intact sagebrush 
landscapes, reducing persistent sources of mortality, and eliminating anthropogenic habitat 
features that subsidize predators. Our analysis also supports efforts to increase chick survival 
and nest success by managing shrub, forb, and grass cover and height to meet published 
brood-rearing and nesting habitat guidelines, but not at the expense of reducing shrub cover 
and height below that required for survival in fall and winter.