1. Department of Zoology and Biodiversity Research Centre; University of British Columbia; 6270 University Blvd. Vancouver BC V6T 1Z4 Canada
2. Institute of Evolutionary Biology and Environmental Studies; University of Zürich; Winterthurerstrasse 190 CH-8057 Zürich Switzerland
3. Avian Evolution Node; Department of Zoology; University of Colombo; PO Box 1490 Colombo 03 Sri Lanka
4. Integrative Biology; ETH Zürich; Universitätstrasse 2 CH-8092 Zürich Switzerland