1. Cornell Lab of Ornithology Ithaca New York USA
2. Swiss Ornithological Institute Sempach Switzerland
3. Department of Physical Geography, Faculty of Geosciences Utrecht University Utrecht Netherlands
4. Lab of Ornithology Institute of Biology, University of Latvia Riga Latvia
5. Swiss Birdradar Solutions AG Winterthur Switzerland
6. University of Massachusetts Amherst Amherst Massachusetts USA