Date of Award:

5-2016

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Wildland Resources

Committee Chair(s)

Terry A. Messmer

Committee

Terry A. Messmer

Committee

Thomas C. Edwards

Committee

Eric T. Thacker

Abstract

The greater sage-grouse (Centrocercus urophasianus; sage-grouse) has been a species of conservation concern since the early 20th century. The decline of populations has largely been attributed to loss and degradation of sagebrush (Artemisia spp.) habitats. To contribute to the knowledge of sage-grouse ecology and quantify the effectiveness of landscape scale habitat manipulations intended to benefit sage-grouse, I monitored habitat use and vital-rates (i.e., nest and brood success) of 45 sage-grouse females in the Box Ender Sage-Grouse Management Area (SGMA) in northwestern Utah. Using telemetry locations of sage-grouse females with known nest and brood fates, I generated statistical models to estimate the influence of proximity to conifer encroachment and conifer removal projects on sage-grouse females selected areas further from conifer removal areas. Similarly, probability of brood success declined as sage-grouse selected for areas further from conifer removal areas. The probability of brood success also declined as sage-grouse females selected sites closer to conifer encroachment areas.

To evaluate sage-grouse habitat-use responses to mechanical conifer removal treatments, I used fecal pellet surveys to estimate relative densities of sage-grouse pellets in conifer encroachment, removal, and undisturbed sagebrush habitats. Sage-grouse pellet densities were highest in undisturbed sagebrush habitats than conifer removal treatments or conifer encroachment. Sage-grouse pellet densities were not statistically different in areas where conifer treatments where completed than conifer encroached areas.

To investigate whether micro-site vegetation characteristics influenced sage-grouse nest or brood success, I analyzed standard vegetation measurements (i.e., Visual Obstruction Reading (VOR), percent shrub canopy, sagebrush canopy, forb canopy, grass canopy, litter, bare ground, and rock cover, and shrub, sagebrush, forb, and grass height) recorded at all radio-marked sage-grouse nests and stratified brood sites from 2014-2015. I also compared these data to vegetation micro-site characteristics collected at random sites. The vegetation micro-site characteristics recorded did not differ between successful and unsuccessful sage-grouse nests. Many vegetation characteristics differed between sites used by successful broods compared to unsuccessful broods. Many vegetation characteristics also differed between sites used by successful broods, and random sites.

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