Results

In the Chihuahuan Desert ecosystem of Fort Bliss, New Mexico, Normalized Difference Vegetation Index alone accounted for up to 82% of the variability in species richness, while image texture derived from aerial photos was the strongest single predictor of species richness (capturing 52% of variation) in the grassland savanna-woodland ecosystem of Fort McCoy, Wisconsin. Maps of avian abundance and occurrence were developed from models using image texture at both installations. The mapping effort revealed that texture measures account for variability within landcover classes, reflecting finescale patterns of species abundance and occurrence that are not apparent in maps based on models using landcover class data only, while retaining a broad-extent perspective. In the Fort McCoy ecosystem, the near-infrared band from Landsat Thematic Mapper imagery accounted for 74% of ground-measured vertical vegetation structure, which is strongly associated with bird distribution patterns. In a focal study on Fort Bliss of the loggerhead shrike, a species of conservation concern, models based on local (i.e., ground measured) and intermediate-scale (i.e., image texture) but not broad-scale (i.e., land cover class) habitat variables best explained shrike occurrence. Finally, the research group conducted an analysis of phenological variation of texture measures in three North American biomes and found that interseasonal variability is strong, which both offers opportunities and presents challenges. The degree to which texture measures were robust to seasonality and scale of analysis was quantified.