Habitat configuration around spotted owl nest and roost sites In northwestern California

摘要: During each breeding season between 1988 and 1992, nests daytime roosts were located for all territorial members of a contiguous population northern spotted owls (Strix occidentalis caurina) in northwestern California. I used guided clustering with Landsat Thematic Mapper data to map land cover types representing seral stages coniferous forest. produced two maps; one had six the other only mature old-growth Map accuracy was estimated be 76.4% 83.6%, respectively, determined by comparing randomly sampled field data. Using these maps grid-based geographic information system, amount area type, habitat heterogeneity, fragmentation, patch number, size forest at nest, roost, random sites. Habitat variables measured within eight concentric circular plots 800 3600 m radii. compared from among sample categories because this plot approximated one-half distance centers owl territories. Nest roost sites similar, less herb nonvegetated cover, slightly lower stage iii more which fragmented arranged fewer but larger patches than points. Mean amounts radius 94.1 ha, 92.0 71.8 sites, respectively. The similar Data estimate characteristics changed non-randomly increasing herbaceous nonvegetated, brush, hardwood, indices fragmentation heterogeneity increased as locations increased. oldgrowth decreased My results Klamath physiographic provence California comparable studies Oregon Washington.