Hierarchical Integrated Population Model for Greater Sage-Grouse (Centrocercus urophasianus) in the Bi-State Distinct Population Segment, California and Nevada.

摘要

This report describes the IPM, which is the first step of a multi-step population analysis. The overall study objective was to develop a stage-based, stochastic population model that included age structure for the Bi-State DPS. A major component of this objective was to compile and quantify multiple sources of survey and demographic data collected over a 10-year period. Recent developments in Bayesian statistical analysis provide the most useful framework to integrate multiple data sources and refine parameter estimation (Kery and Shaub, 2012). Therefore, we integrated our data into a Bayesian modeling framework with the purpose of deriving numerous population parameters to better understand population dynamics in the Bi-State DPS. In the first step of the analysis, we derived these parameters specifically to: (1) estimate population growth rates (E) for the Bi-State; (2) estimate population vital rates for each life history stage; (3) identify differences in rates between age classes; (4) identify differences in rates between subpopulations; and (5) identify temporal patterns in population vital rates and E. A second step of this analysis will be carried out to estimate the relative importance of specific vital rates (for example, adult survival, nest success, chick survival) to sage-grouse persistence using sensitivity, elasticity, and retrospective correlation analyses. In a final step, environmental covariates will be fit to the estimated rates. This report provides methods and results for the first step of the analysis only. The report findings will be useful as decision support for conservation and management of the Bi-State DPS, as well as for specific subpopulations.