Surveying for Spotted Owls in the northeastern portion of North Cascades National Park Service Complex, 2009-2010: Report for the 2009 field season

Siegel, Rodney; Wilkerson, Robert; Kuhlman, Karah; Kuntz, Robert

This public version has had information relating to locations of Spotted Owl (listed species) removed. To obtain the original report containing all information it is required to contact the National Park Service author and sign a confidentiality agreement.Northern Spotted Owl populations have declined over the last century, and the subspecies has been listed by the federal government as “threatened” since 1990. The status of the northern Spotted Owl has not been well documented in the North Cascades of Washington and southwestern British Columbia. In 1993, National Park Service (NPS) resource management staff initiated the first comprehensive inventory of Spotted Owls in suitable habitat within North Cascades National Park Service Complex (NOCA), a four-year survey that identified 11 active Spotted Owl territories in NOCA.During the ten years following completion of NOCA’s 4-year baseline owl inventory in 1996, only sporadic compliance-related owl surveys occurred. More comprehensive, up-to-date information on the status of the park’s Spotted Owl population was needed to aid NPS managers updating NOCA’s Fire Management Plan and other management and compliance related activities. In response to these needs, NPS partnered with The Institute for Bird Populations to initiate a multi-year study of the status of the NOCA’s Spotted Owl population. The project has three main objectives:1. Revise NOCA’s model of suitable habitat for Spotted Owl and develop a revised GIS map layer showing suitable Spotted Owl habitat throughout the park.2. Resurvey transects that were established and surveyed from 1993 through 1996; locate active Spotted Owl territories, estimate relative abundance, and determine productivity at all activity sites found.3. Develop individual Spotted Owl activity site management plans with recommendations for protection measures for both currently active and historic sites.During the first year of the project, we revised NOCA’s model of suitable Spotted Owl habitat, in completion of Objective 1 (Wilkerson and Siegel 2007). During 2007 and 2008 we conducted fieldwork throughout the Stehekin River watershed and along Lake Chelan within Lake Chelan National Recreation Area (Siegel et al. 2008), in completion of Objective 2 for the portion of NOCA that lies east of the Cascades crest. In 2009 we began a two-year effort to complete Objective 2 for the upper Skagit River watershed in NOCA. Year 1 (2009) focused on the northeastern portion of the watershed, including the Newhalem Creek, Panther Creek, Ross Lake, Ruby Creek, and Thunder Creek drainages. This report details our results from spring and summer 2009, the first field season of our current efforts in this portion of the park. We surveyed transects throughout the five selected drainages, using survey procedures that were virtually identical to those used during the 1990s survey, and our 2007-2008 surveys in the greater Stehekin and Lake Chelan areas. In 2009 we completed 75 visits to 38 survey transects, amounting to 1,270 2-min or 10-min station surveys, plus 13 follow-up visits to historic Spotted Owls activity sites. None of our transect surveys during the 2009 field season yielded Spotted Owl detections, but our follow-up visits to sites with historical detections confirmed at least one resident Spotted Owl.Although our survey was designed specifically to detect Spotted Owls, we also documented all detections of other owl species. Throughout the season, we observed and documented individuals of five additional owl species: Great Horned Owl (2 detections, likely representing a single activity site), Barred Owl (69 detections, representing an estimated 18 activity sites), Western Screech-Owl (2 detections, at distinct sites), Northern Pygmy-Owl (7 detections, likely representing 6 distinct sites), and Northern Saw-whet Owl (8 detections, likely representing 5 distinct sites).

Surveying for Spotted Owls in the northeastern portion of North Cascades National Park Service Complex, 2009-2010: Report for the 2009 field season

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