1 The Helsinki Lab of Ornithology, Finnish Museum of Natural History, University of Helsinki, Helsinki, FI-00014, Finland.
2 Helsinki Institute of Sustainability Science, University of Helsinki, Helsinki, FI-00014, Finland.
3 FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, University of Cape Town, Cape Town, South Africa.
4 cE3c - Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group and Universidade dos Acores - Depto de Ciencias e Engenharia do Ambiente, Angra do Heroısmo, Acores, PT-9700-042, Portugal.
5 HawkWatch International, Salt Lake City, UT, 84106, U.S.A.
6 Department of Biology, University of Utah, Salt Lake City, UT, 84112, U.S.A.
7 Endangered Wildlife Trust, Modderfontein, 1609, South Africa.
8 Digital Geography Lab, Department of Geosciences and Geography, University of Helsinki, Helsinki, FI-00014, Finland.
9 School of Life Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa.
10 Finnish Museum of Natural History Luomus, University of Helsinki, P.O. Box 17, Helsinki, FI-00014, Finland.
11 Department of Geosciences and Geography, University of Helsinki, Helsinki, FI-00014, Finland.