| Great Gray Owls (Strix nebulosa) in the Sierra Nevada were once believed to nest rather strictly within mid-elevation conifer forests near montane meadows. However, Great Gray Owl nests, mostly in large oak trees and often far from montane meadows, have recently been discovered in commercially managed forests of the lower-montane zone, where oak-dominated woodlands transition to conifer-dominated forests. We describe the reproductive success, apparent occupancy rate, and habitat associated with eight Great Gray Owl nests monitored between 2006-2015 on Sierra Pacific Industries timberlands. Reproductive success was high, with several nesting attempts producing three fledglings, and an average of 1.8 +/- 1.0 chicks fledged during 22 nesting attempts. In the years following the discovery of a territory, apparent occupancy averaged 87.3% +/- 19.9%. Our results suggest that the lower-montane zone may provide high quality nesting habitat for Great Gray Owls. We also used Maxent to identify potential Great Gray Owl nesting habitat throughout the lower-montane zone of the Sierra Nevada, based on conditions around the nests we studied. Our model identified areas within 10 counties of the central and northern Sierra Nevada that we recommend be surveyed for Great Gray Owls. |