Specifications include, but are not limited to: NDOW is seeking a qualified vendor to build models to estimate common raven populations statewide, estimate historical population trends of common ravens statewide, increase understanding of various common raven thresholds and their impacts on Greater sage-grouse, and increase understanding of anthropogenic subsidies on common raven populations. These models will also complement existing work with Greater sage-grouse brood survival; the aforementioned models will help the department identify areas where lethal and nonlethal common raven management is necessary. The vendor will provide their findings in either a peer reviewed manuscript and/or a scientific presentation. 1. Objectives: The major objective of this effort is the following: Model raven populations, quantify their impacts to Great-sage grouse, and improve understanding of subsidy use.