Code for a hierarchical model of raven densities linked with sage-grouse nest survival to help guide management of subsidized avian predators, version 1.0

This repository includes R code to conduct hierarchical density surface modeling of common raven (Corvus corax) point count data and hierarchical shared frailty modeling of Greater sage-grouse (Centrocercus urophasianus) nest fates. The model components are quantitatively linked, such that estimates of raven density from the hierarchical distance sampling component are spatially registered to sage-grouse nest locations. This facilitates estimation of the effects of raven density on sage-grouse nest survival, while accounting for other environmental influences measured at similar spatial scales. Data informing the raven density component comprised point count surveys, while data informing sage-grouse nest survival comprised nest fates and encounter histories. Data collection for the study was carried out during 2009-2019 at field site locations within California, Idaho, and Nevada, USA.