A MANAGEMENT DRIVEN INVESTIGATION OF LANDSCAPE PATTERNS OF NORTHERN SPOTTED OWL NESTING TERRITORIES IN THE HIGH CASCADES OF OREGON

Investigations using available data sought to guide short-term managem ent decisions regarding the needs of northern spotted owl in the high Cascade Mountains of Oregon. Landscape attributes and pattern indices were measured and tested for identification of areas likely to contain northern spotted owl nests. Predictive models indicating planning sta ndards were developed. Most landscape ecological indices were not usef ul. Results indicate the owl favors landscapes dominated by patches th at meet definitions of late seral forest nesting habitat. The owl opti mally nests in such patches at least 570 hectares in size. Landscapes with some edges, particularly around nesting habitat patches evidently do not adversely affect the owl, perhaps because they provide prey. L andscapes with extensive edges, particularly between openings and fore sts not suitable for nesting, are not as likely to be selected. The re sults are largely consistent with the owl's recovery plans, provide gu idance for management, and require refinement through additional resea rch, particularly to better determine home range sizes.