CALIFORNIA SPOTTED OWL HABITAT SELECTION IN THE CENTRAL SIERRA-NEVADA

We examined habitat selection by California spotted owls (Strix occide ntalis occidentalis) at 3 spatial scales: landscape, habitat patch, an d microsite. We compared landscape characteristics within 457-ha circl es surrounding 25 owl activity centers to randomly selected areas of e qual size. Owl activity centers were defined as the geometric center o f the minimum convex polygon enclosing roosts and nests located betwee n 1986 and 1992. Baxter-Wolf indices of habitat interspersion were low er in owl sites than in random sites suggesting that owl sites contain ed fewer habitat patches. Ninety-seven percent of the habitat patches in which owls roosted were characterized by residual (i.e., > 100 cm d bh [diameter at breast height]) trees. Owl roost and nest sites also w ere characterized by residual trees and high structural diversity. Cur rent forest classification procedures generally fail to detect this re sidual tree component, which has important implications for habitat co nservation of the owl.