Direct Identification of Northern Sage-grouse, Centrocercus urophasianus, Nest Predators Using Remote Sensing Cameras

The status and apparent decline of Sage-grouse (Centrocercus spp.) has been of increasing concern and lower nesting success could be contributing to population declines. Our objective was to directly identify Sage-grouse nest predators. Following visual confirmation of radio-marked Sage-grouse nest establishment in 1997-1999, we installed automatic 35 mm cameras controlled by an active infrared monitor. Of 26 nests monitored by cameras, 22 successfully hatched and four were unsuccessful. American Elk (Cervus canadensis), Badger (Taxidea taxus), and Black-billed Magpie (Pica hudsonia) destroyed three of the four unsuccessful nests, and domestic cattle caused abandonment of the fourth. Richardson’s (Spermophilus richardsonii) and Thirteen-lined Ground Squirrels (S. tridecemlineatus) were recorded at nests, but were not detected in predation

Identifying and Prioritizing Greater Sage-Grouse Nesting and Brood-Rearing Habitat for Conservation in Human-Modified Landscapes

BACKGROUND: Balancing animal conservation and human use of the landscape is an ongoing scientific and practical challenge throughout the world. We investigated reproductive success in female greater sage-grouse (Centrocercus urophasianus) relative to seasonal patterns of resource selection, with the larger goal of developing a spatially-explicit framework for managing human activity and sage-grouse conservation at the landscape level. METHODOLOGY/PRINCIPAL FINDINGS: We integrated field-observation, Global Positioning Systems telemetry, and statistical modeling to quantify the spatial pattern of occurrence and risk during nesting and brood-rearing. We linked occurrence and risk models to provide spatially-explicit indices of habitat-performance relationships. As part of the analysis, we offer novel biological information on resource selection during egg-laying, incubation, and night. The spatial pattern of occurrence during all reproductive phases was driven largely by selection or avoidance of terrain features and vegetation, with little variation explained by anthropogenic features. Specifically, sage-grouse consistently avoided rough terrain, selected for moderate shrub cover at the patch level (within 90 m(2)), and selected for mesic habitat in mid and late brood-rearing phases. In contrast, risk of nest and brood failure was structured by proximity to anthropogenic features including natural gas wells and human-created mesic areas, as well as vegetation features such as shrub cover. CONCLUSIONS/SIGNIFICANCE: Risk in this and perhaps other human-modified landscapes is a top-down (i.e., human-mediated) process that would most effectively be minimized by developing a better understanding of specific mechanisms (e.g., predator subsidization) driving observed patterns, and using habitat-performance indices such as those developed herein for spatially-explicit guidance of conservation intervention. Working under the hypothesis that industrial activity structures risk by enhancing predator abundance or effectiveness, we offer specific recommendations for maintaining high-performance habitat and reducing low-performance habitat, particularly relative to the nesting phase, by managing key high-risk anthropogenic features such as industrial infrastructure and water developments