Population Dynamics of Columbian Sharp-tailed Grouse in Idaho
April 2020 - April 2021
- Idaho Department of Fish and Game
Abundance of Columbian sharp-tailed grouse has declined and state agencies must set annual harvest regulations that ensure that harvest is sustainable without adversely affecting the bird’s persistence. Currently monitoring efforts to estimate annual abundance are based on lek counts, but their reliability is unknown. We will use lek count data, harvest and hunter effort data, and age ratio data (from harvest) to estimate abundance of sharp-tailed grouse in Idaho. Will use multiple counts per year at leks to estimate and incorporate detection error (i.e., prob of grouse being detected given present) into models. We will conduct analyses of spatial-temporal patterns in maximum lek counts based on a generalized mixed model analysis to describe spatial-temporal patterns in lek counts. We will also conduct analyses of spatial-temporal patterns in raw lek counts (survey level data) to build generalized mixed models to describe spatial-temporal changes in relative abundance, and factors related to relative abundance, while incorporating survey-level detection covariates directly into analyses. We will also conduct analyses of spatial-temporal patterns of lek occupancy; build hierarchical occupancy models to provide a more thorough understanding of the spatial distribution of lekking sharp-tailed grouse in southern Idaho, how lek occupancy has changed over time (i.e., range contraction-expansion), and possibly identify factors that influence lek occupancy.