1. Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Road, Unit 3043, Storrs, CT 06269, USA
2. The Institute for Bird Populations, PO Box 1346, Point Reyes Station, CA 94956, USA
3. Cornell Laboratory of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA
4. USDA Forest Service, Pacific Southwest Region, 1323 Club Drive, Vallejo, CA 94592, USA
5. USDA Forest Service, Pacific Southwest Research Station, 800 Buchanan Street, Albany, CA 94710, USA