Acknowledgments
We thank all our assistants and volunteers, in particular S. Bartholdi, A. Berger, S. Blatter, M. Büttel, E. Christen, N. Erath, M. Fader, L. Fischer, A. Grendelmeier, H. Greter, M. Hauptvogel, M. Hertach, F. Hoffet, J. Huber, L. Huber-Eustachi, A. Koller, C. Labhart, M. Lörcher, E. Lutz, S. Meier, S. Meyer, L. Michel, C. Mischler, J. Naef, F. Nyffeler, C. Portmann, H. Reers, O. Rickenbach, A. Schärer, S. Schmieder, J. Schoop, M. Spinelli, J. Staggenborg, I. Stützle, S. M, Treffler, D. Trobe and I. Weinberger for their effort in the field, and E. Keil for her kind hospitality. Many thanks also to V. Michel for coordinating much of the field work. We are very grateful to L. Jenni and G. Pasinelli for their valuable comments on earlier drafts of the manuscript. W. Fiedler from the Max Planck Institute of Ornithology (today Max Planck Institute of Animal Behaviour) provided logistic and administrative support. Capture and tagging of little owls were permitted by the regional council of Baden-Württemberg, Germany (permit No 35-9185.81/0288). Radio-tracking was conducted under license of Deutsche Bundesnetzagentur (license No 37 55 5413). This work was funded by the Swiss National Science Foundation (Grant 3100A 132951/1 to Beat Naef-Daenzer and Martin Grüebler), the Hirschmann Foundation, and the Karl Mayer Foundation.