Sharp -tailed grouse breeding success, survival, and site selection in relation to habitat measured at multiple scales

Ground dwelling birds often have low breeding success in landscapes disturbed by cropland or heavily grazed by domestic stock. Predation is the proximate cause of nest failure or death for many birds and areas disturbed by humans often have higher numbers of generalist predators than do more pristine habitats. At smaller scales, changes to vegetation cover or tree encroachment may increase predator efficiency at finding prey. In this thesis, I used habitat measured at multiple extents to explain the breeding success and survival of sharp-tailed grouse (Tympanuchus phasianellus), and include scales relevant for predator dynamics at small and large extents. Corvid density was higher and grouse nests were less successful in landscapes (1,600-m extent) with higher proportions of crop and sparsely covered grassland (sparse grassland). Nest success increased with greater heights of concealment cover within 50 m of nests. Chick survival was 0.41 (SE +/- 0.08) from hatch to 30 days post-hatch. Hens with more bare grassland and crop within their home range (583 m) were less likely to rear ≥1 chick to 30 days. Raptor density was higher in areas with more sparse grassland (non-linear) and wetland (1,600-m extent). Moreover, hen survival was lower in areas with more crop and sparse grassland at broad extents (0.45 +/- 0.07 SE vs. 0.62 +/- 0.07 SE, 1,600 m). Hence, human-related disturbance was linked with lower reproduction and survival for grouse. My work culminated in a simulation analysis that evaluated how population growth in human disturbed landscapes responded to management alternatives. Those that improved nest success had the largest influence on population growth.