Oak wilt is a fatal disease of oaks caused by the fungus Ceratocystis fagacearum. Loss or degradation of habitat due to the disease may negatively affect the federally endangered golden-cheeked warbler (Setophaga chrysoparia). To assess the impact of oak wilt on golden-cheeked warblers, I investigated its influence on habitat selection and quality. I used remote sensing to estimate the amount of potential golden-cheeked warbler habitat currently affected by oak wilt, to predict the amount of potential habitat likely to be affected in the near future, and to assess the current probability of warbler occupancy in areas affected by oak wilt historically. I also quantified vegetative characteristics to assess overstory vegetation and regeneration in areas affected by the disease. I found proportional occupancy and territory density in unaffected areas to be, respectively, 3.5 and 1.8 times that of affected areas. Pairing success was 27% lower for territories containing oak wilt but fledging success was not affected. I estimated that 6.9% of potential golden-cheeked warbler habitat and 7.7% of the total area within my study region was affected by oak wilt in 2008. By 2018, I predicted that 13.3% of potential golden-cheeked warbler habitat and 16.0% of the study region would be affected by the disease. Using historical imagery, I found that areas affected by oak wilt in the past are less likely to be classified as current potential warbler habitat than areas never affected by the disease. I found no differences between the understory vegetation of affected and unaffected areas but that oaks were more common in the overstory than in the understory, suggesting that species composition in affected areas may shift in the years following an outbreak of the disease. My results suggest that the presence of oak wilt negatively influences habitat selection and quality for golden-cheeked warblers, likely due to reduced canopy cover in susceptible oak species. Additionally, oak wilt frequently occurs in golden-cheeked warbler habitat and will continue to spread into warbler habitat in the coming years. Future management efforts should address the threat oak wilt poses to golden-cheeked warblers by incorporating applicable preventative measures.

This dissertation is a treatise on spatially-explicit resource selection on two very different vertebrate species. The North Atlantic right whale (Eubalaena glacialis) is the most endangered large whales in the world. Ship strikes and fishing gear entanglement are impediments to recovery. The gopher tortoise (Gopherus polyphemus) is an imperiled species whose upland habitats are shrinking from urban and agricultural development. Determining spatial distribution of important resources is important for conservation strategies. Historical and modern thinking of habitat selection theory and analytical techniques are reviewed and applied to these species. Fine-scale resource selection of sea surface temperature (SST), derived from AVHRR imagery, is evaluated for right whales in the southeastern U. S. calving grounds. Aerial survey data (December-March, 1991-1998) including survey tracklines and right whale locations were entered into a Geographic Information Systems (GIS) for comparing whale use of SST to availability based on search effort. Using Monte Carlo techniques, mean and standard deviation for SSTs and latitudes of whale-sightings were compared to sampling distributions derived from available SSTs and latitudes. From these data, it was concluded that the North Atlantic right whale uses SSTs and latitudes non-randomly. Broad-scale habitat selection for gopher tortoises was evaluated from the 2003 Land Cover/Land Use map (Florida Fish and Wildlife Conservation Commission). Based on land cover and ancillary data, potential gopher tortoise habitat was developed for northeast Florida.