INTEGRATING GPS TAG LOCATIONS AND NEST MONITORING VIDEO REVEALS NEW INSIGHTS INTO SPOTTED OWL FORAGING BEHAVIOR

Ceeanna J Zulla; University of Wisconsin - Madison; zulla@wisc.edu; H. Anu Kramer, Gavin M. Jones, John J. Keane, Kevin N. Roberts, Brian P. Dotters, Sarah C. Sawyer, Sheila A. Whitmore, William J. Berigan, Kevin G. Kelly, Amy K. Wray, M. Zachariah Peery

Characterizing habitat conditions that promote successful foraging by predator species is important for their conservation. However, distinguishing sites of specific successful prey captures from general locations of individual animals is not possible using traditional telemetry methods. We integrated high spatial and temporal resolution GPS tagging with video nest monitoring to identify foraging movement patterns, predation events, prey species captured, and habitat characteristics of sites where California spotted owls (Strix occidentalis occidentalis) captured prey. We monitored 15 males and their nests to identify 127 prey capture locations, 91 (72%) of which were identified to a specific prey species using video monitoring. Owls tended to capture woodrats, Neotoma fuscipes, a primary prey species, in areas with more: (i) large-tree forest, (ii) young forest, (iii) medium trees/medium canopy forest, (iv) heterogeneity, and (v) hardwood-conifer edge – while avoiding areas with more medium trees/high canopy forest. Owls primarily captured flying squirrels, Glaucomys oregonensis, a second primary prey species, in areas with more large-tree forest. This information can be used to strengthen conservation planning by incorporating mechanistic knowledge about which habitats promote the acquisition of key prey while also integrating conservation plans with forest restoration activities intended to promote resilient landscapes.

Spotted Owl Ecological Associations   Student Paper Zoom Presentation