International census and population trends for Bewicks Swans Cygnus columbianus bewickii wintering from the East Mediterranean to Central Asia

Rees E.C. Rozenfeld S. Vangeluwe D. Ioannidis P. Erciyas-Yavuz K. Belousova A. Rustamov E. Solokha A. Sultanov E. Kowallik C. Portolou D. Khrokov A. Šćiban M. Ajder V. Zenatello M. Koffijberg K. Kirtaev G. Rogova N. Ghasabyan M. Wood K.A. Langendoen T. Nagy S. Clausen P. Fox A.D.
2024 Wildfowl and Wetlands Trust

Wildfowl
2024 179 - 201 pp.

Trends in abundance and changes in the distribution of the Northeast Europe/ Northwest Europe Bewick’s Swan Cygnus columbianus bewickii population have been studied in detail since the second half of the 20th century, but much less is known about the Northwestern Siberia/Caspian population which was estimated at 1,000–1,500 individuals at the turn of the century. Here, we describe the results of the first species-specific mid-winter International Bewick’s Swan Census (IBSC) covering the East Mediterranean to Central Asia, made in January 2020. We also use longer-term data collated by Wetlands International through the annual International Waterbird Census (IWC) programme to construct trends in wintering numbers in the region. Results from the IBSC and IWC both showed a marked increase in population size for the Northwestern Siberia/Caspian Bewick’s Swans over the past two decades. A total of 6,819 was recorded during the IBSC and there was a five-year mean of 9,111 ± 4,300 swans reported to the IWC (for the years 2018–2022) with a peak count of 13,775 in 2019. An aerial survey of the Volga Delta in the northern Caspian Sea in 2020, rarely covered because of the logistical difficulties of carrying out midwinter counts in the region, found an estimated 551 Bewick’s Swans wintering at the site. There was marked annual variation in the IWC counts recorded from 2017 onwards, although the reasons for these fluctuations remain unknown. Trends analysis suggested a slow increase over time from 2000–2015, followed by a period of rapid increase during 2015–2017, then a weak decline in 2017–2022. Given that the IBSC and the IWC have provided totals of > 6,000 Bewick’s Swans in five of the last six years, however, we propose that the new population estimate should be increased to 6,000–13,000 birds, pending further comprehensive surveys of the whole region.

central Asia , distribution , population trends , southeast Europe , swans

Text of the article Перейти на текст статьи

Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russian Federation
Royal Belgian Institute of Natural Sciences, Vautier Street 29, Brussels, 1000, Belgium
Evros Delta Management Body, Alexandroupoli, 68100, Greece
Ornithological Research Center, Ondokuz Mayis University, Kurupelit, Samsun, 55139, Turkey
All-Russian Research Institute for Environmental Protection, Moscow, Russian Federation
Menzbier Ornithological Society (Central Asian Branch), Institute of Deserts, Flora and Fauna of Turkmenistan, No. 38 Ramsar Convention Office (Building 2), 15 Bitarap Shaely Avenue, Ashgabat, 744000, Turkmenistan
Russian State Agrarian Correspondence University, 50 St. Shosse Entuziastov, Balashikha, 143907, Russian Federation
Azerbaijan Ornithological Society, M. Mushfiq 4B, Apt. 60, Baku, AZ1004, Azerbaijan
Biologische Station Westliches Ruhrgebiet, Lösorter Strasse 119, Duisburg, 47137, Germany
Hellenic Ornithological Society, Agiou Konstantinou 52 Street, Athens, 10437, Greece
ACBK (BirdLife Kazakhstan), 67 Khodzhanov St., 205, Almaty, 050060, Kazakhstan
Bird Protection and Study Society of Serbia, Radomira Raše Radujkova 1a, Novi Sad, 21000, Serbia
Institutul de Ecologie şi Geografie, Universitatea de Stat din Moldova, Chişinău, Moldova
Marine Biological Research Station “Prof. Dr. Ioan Borcea”, Alexandru Ioan Cuza University of Iasi, Agigea, Romania
Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Via Ca’ Fornacetta 9, Ozzano dell’Emilia, 40064, Italy
SOVON, Dutch Centre for Field Ornithology, PO Box 6521, Nijmegen, 6503 GA, Netherlands
Goose, Swan, and Duck Study Group of Northern Eurasia, Moscow, 109052, Russian Federation
Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, 53706, WI, United States
Armenian Society for The Protection of Birds, P. Sevak 7, Yerevan, 0014, Armenia
Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire, GL2 7BT, United Kingdom
Wetlands International, Horapark 9, LZ, Ede, NL-6717, Netherlands
Department of Ecoscience, Aarhus University, C.F. Møllers Allé 8, Aarhus, DK-8000, Denmark

Department of Zoology
Severtsov Institute of Ecology and Evolution
Royal Belgian Institute of Natural Sciences
Evros Delta Management Body
Ornithological Research Center
All-Russian Research Institute for Environmental Protection
Menzbier Ornithological Society (Central Asian Branch)
Russian State Agrarian Correspondence University
Azerbaijan Ornithological Society
Biologische Station Westliches Ruhrgebiet
Hellenic Ornithological Society
ACBK (BirdLife Kazakhstan)
Bird Protection and Study Society of Serbia
Institutul de Ecologie şi Geografie
Marine Biological Research Station “Prof. Dr. Ioan Borcea”
Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA)
SOVON
Goose
Department of Forest and Wildlife Ecology
Armenian Society for The Protection of Birds
Wildfowl & Wetlands Trust
Wetlands International
Department of Ecoscience

10 лет помогаем публиковать статьи Международный издатель

Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026