1. Department of Ecology and Evolution University of Lausanne Lausanne CH‐1015 Switzerland
2. Division of Conservation Biology Institute of Ecology and Evolution University of Bern Bern CH‐3012 Switzerland
3. Functional Agrobiodiversity University of Göttingen Göttingen D‐37077 Germany
4. Ethiopian Wildlife Conservation Authority Head Office, Mexico Square Addis Ababa 386 Ethiopia
5. Swiss Ornithological Institute Valais Field Station Sion CH‐1950 Switzerland