1. Department of Biology, University of Turku, Yliopistonmäki (Vesilinnantie 5), Natura, 20014 Turku, Finland; ORCID: 0000-0002-0848-1676
2. Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria
3. FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Private Bag X3, John Day, 7701 Rondebosch, Cape Town, South Africa
4. Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Scottsville, P/Bag X01, 3209, South Africa
5. Department of Biology, National University of Mongolia and Mongolian Ornithological Society, PO Box 537, Ulaanbaatar 210646A, Mongolia; ORCID: 0000-0002-6320-2182.