CANOPY CLOSURE AROUND NEST SITES OF MEXICAN SPOTTED OWLS IN NORTHCENTRAL ARIZONA

We analyzed variation in canopy closure around 47 Mexican spotted owl (Strix occidentalis lucida) nest sires and 47 random forest sites on t he Coconino National Forest in northcentral Arizona. We mapped distinc t habitat polygons on 1:15,840 color aerial photographs, assigned each polygon to one of 4 canopy-closure classes (<10, 10-40, 41-70, or >70 %), and measured tile area in each canopy class within 5 concentric an alysis zones with radii of 0.1, 0.4, 0.8, 1.2, and 1.6 km (delineating rings of about 4, 47, 150, 252, and 352 ha). Landscape composition di ffered between spotted owl nest and random sites (P < 0.001), Differen ces were greatest within 0.4 km of nest and random sites but persisted across all analyses zones. Nest sites contained more area in the >70% canopy-closure class and less area in the < 10% class, Tile most abun dant canopy class was 41-70%, except within 0.1 km of nests, where >70 % canopy predominated Nesting spotted owls selected areas with denser canopy than randomly available forest landscapes, but outside the imme diate nest area (>0.8 km) canopy closure approached that of the surrou nding forest.