Age and sex ratios of wintering Long-tailed Ducks Clangula hyemalis can be determined by analysis of photos of flying flocks at sea: A method description
Keywords:Baltic Sea, population dynamics, reproductive success, flock structure, plumage
The West Siberian/North European population of Long-tailed Duck Clangula hyemalis that breeds in Fennoscandia and Northwestern Russia, and winters in the Baltic Sea, has declined by at least 65% since the 1990s and is classified as globally vulnerable. To propose effective management actions to stop the decline, knowledge about demographic parameters is required. A photo survey method by which it is possible, in winter, to collect data on sex ratios and production of first-winter birds is presented here. The plumage traits and bill patterns, which are detectable in photos taken at a distance, are described. The traits can be used to discriminate between three categories of birds: adult males, first-winter males, and females. To extrapolate results from several photo surveys and obtain population-wide estimates of demographic parameters, knowledge about non-random distributions of different bird categories is needed. It was found that different age and sex categories were distributed differently across flocks of different sizes. The required sample sizes and the possible constraints and biases related to the photo survey method are discussed.
Aharon-Rotman Y, Soloviev M, Minton C, Tomkovich P, Hassell C & Klaassen M. 2015. Loss of periodicity in breeding success of waders links to changes in lemming cycles in Arctic ecosystems. Oikos 124: 861–870. https://doi.org/10.1111/oik.01730
Bellebaum J, Schirmeister B, Sonntag N & Garthe S. 2012. Decreasing but still high: bycatch of seabirds in gillnet fisheries along the German Baltic coast. Aquatic Conservation: Marine and Freshwater Ecosystems 23: 210–221. https://doi.org/10.1002/aqc.2285
Bergman G. 1974. The spring migration of the Long-tailed Duck and the Common Scoter in western Finland. Ornis Fennica 51: 129–145. Available at https://lintulehti.birdlife.fi:8443/pdf/artikkelit/1027/tiedosto/of_51_129-145_artikkelit_1027.pdf
Durinck J, Skov H, Jensen FP & Pihl S. 1994. Important marine areas for wintering birds in the Baltic Sea. – EU DG XI Research Contract no. 2242/90-09-01. Ornis Consult Report 1994, 110 pp. Available at https://www.researchgate.net/publication/275678381_Important_Marine_Areas_for_Wintering_Birds_in_the_Baltic_Sea/link/5570424b08aefcb861ddd7c4/download
Efron B & Tibshirani RJ. 1994. An Introduction to the Bootstrap. Chapman and Hall/CRC, Boca Raton, FL, USA.
Fowler J, Cohen L & Jarvis P. 1998. Practical Statistics for Field Biology, second edition. Wiley, Chichester.
Hario M, Rintala J & Nordenswan G. 2009. Dynamics of wintering Long-tailed Ducks in the Baltic Sea – the connection with lemming cycles, oil disasters, and hunting. Suomen Riista 55: 83–96. (in Finnish, with English summary).
Hearn RD, Harrison AL & Cranswick PA. 2015. International Single Species Action Plan for the Conservation of the Long-tailed Duck (Clangula hyemalis). AEWA Technical Series No. 57. AEWA, Bonn, Germany. Available at https://www.unep-aewa.org/sites/default/files/publication/aewa_ts57_issap_ltd.pdf
Karwinkel T, Pollet IL, Vardeh S, Kruckenberg H, Glazov P, Loshchagina J, Kondratyev A, Merkel B, Bellebaum J & Quillfeldt P. 2020. Year‑round spatiotemporal distribution pattern of a threatened sea duck species breeding on Kolguev Island, south‑eastern Barents Sea. BMC Ecology 20: 31. https://doi.org/10.1186/s12898-020-00299-2
Lehikoinen A, Kondratyev AV, Asanti T, Gustafsson E, Lamminsalo O, Lapshin NV, Pessa, J & Rusanen P. 2006. Survey of arctic bird migration and staging areas at the White Sea, in the autumns of 1999 and 2004. The Finnish Environment 25. Finnish Environment Institute, Helsinki. Available at http://hdl.handle.net/10138/38722
Larsson K. 2022. Age and sex ratios in the declining West Siberian/ North European population of Long-tailed Duck wintering in the Baltic Sea: Implications for conservation. Ornis Fennica 99: 117–131. https://doi.org/10.51812/of.113681
Larsson K & Tydén L. 2005. Effects of oil spills on wintering Long-tailed Ducks Clangula hyemalis at Hoburgs bank in central Baltic Sea between 1996/97 and 2003/04. Ornis Svecica 15: 161–171. [In Swedish with English summary.] https://doi.org/10.34080/os.v15.22740
Loshchagina J, Vardeh S, Glazov P, Pollet IL & Quillfeldt P. 2019. Long-tailed Duck (Clangula hyemalis) ecology: insights from the Russian literature. Part 2: European part of the Russian breeding range. Polar Biology 42: 2277–2297. https://doi.org/10.1007/s00300-019-02595-0
Nilsson L. 2016. Changes in numbers and distribution of wintering Long-tailed Ducks Clangula hyemalis in Swedish waters during the last fifty years. Ornis Svecica 26: 162–176. https://doi.org/10.34080/os.v26.21855
Nolet BA, Bauer S, Feige N, Kokorev YI, Popov IY & Ebbinge BS. 2013. Faltering lemming cycles reduce productivity and population size of a migratory Arctic goose species. Journal of Animal Ecology 82: 804–813. https://doi.org/10.1111/1365-2656.12060
Petersen IK, Mackenzie ML & Scott-Hayward LAS. 2018. Long-term impacts on Long-tailed Duck distributions resulting from the construction of the Rødsand II and Nysted offshore wind farms, Denmark. Technical Report from DCE – Danish Centre for Environment and Energy No. 120. Aarhus University, DCE – Danish Centre for Environment and Energy, Aarhus, Denmark. 20 pp. Available at http://dce2.au.dk/pub/TR120.pdf
Quillfeldt P, Morkūnas J, Kruckenberg H, Kondratyev A, Loshchagina J, Aarvak T, Jostein Oien J, Bellebaum J & Glazov P. 2021. Year‑round movements of Long‑tailed Ducks Clangula hyemalis from Kolguev Island, Barents Sea. Polar Biology 45: 71–87. https://doi.org/10.1007/s00300-021-02973-7
Reeber S. 2015. Wildfowl of Europe, Asia and North America. Helm Identification Guides. Bloomsbury Publishing Plc, London, UK.
Rintala J, Hario M, Laursen K & Møller AP. 2022. Large scale changes in marine and terrestrial environments drive the population dynamics of long tailed ducks breeding in Siberia. Scientific Reports 12: 12355. https://doi.org/10.1038/s41598-022-16166-7
Robertson GJ. 2008. Using winter juvenile/adult ratios as indices of recruitment in population models. Waterbirds 31: 152–158. https://doi.org/10.1675/1524-4695-31.sp2.152
Savard J-PL & Petersen MR. 2015. Remigial Molt of Sea Ducks. Pp 305–335 in Ecology and Conservation of North American sea ducks. Studies in Avian Biology, Volume 46 (Savard, J-PL, Derksen DV, Esler D & Eadie JM, eds). CRC Press, Boca Raton, FL, USA.
Skov H, Heinanen S, Žydelis R, Bellebaum J, Bzoma S, Dagys M, Durinck J, Garthe S, Grishanov G, Hario M, Kieckbusch JJ, Kube J, Kuresoo A, Larsson K, Luigujoe L, Meissner W, Nehls HW, Nilsson L, Petersen IK, Roos MM, Pihl S, Sonntag N, Stock A, Stipniece A & Wahl J. 2011. Waterbird populations and pressures in the Baltic Sea. TemaNord 2011:550. Nordic Council of Ministers, Copenhagen, Denmark. Available at https://www.norden.org/en/publication/waterbird-populations-and-pressures-baltic-sea.
Sokolov V, Vardeh S & Quillfeldt, P. 2019. Long‑tailed Duck (Clangula hyemalis) ecology: insights from the Russian literature. Part 1: Asian part of the Russian breeding range. Polar Biology 42: 2259–2276. https://doi.org/10.1007/s00300-019-02594-1
Stempniewicz L. 1994. Marine birds drowning in fishing nets in the Gulf of Gdansk (southern Baltic): numbers, species composition, age and sex structure. Ornis Svecica 4: 123–132. https://doi.org/10.34080/os.v4.23026
Waldeck P & Larsson K. 2013. Effects of winter water temperature on mass loss in Baltic blue mussels: Implications for foraging sea ducks. Journal of Experimental Marine Biology and Ecology 444: 24–30. https//doi.org/10.1016/j.jembe.2013.03.007
Wetlands International. 2021. Waterbirds Populations Portal. https://wpp.wetlands.org/
Wood KA, Brides K, Durham ME & Hearn RD. 2021. Adults have more male‑biased sex ratios than first‑winter juveniles in wintering duck populations. Avian Research 12: 51. https://doi.org/10.1186/s40657-021-00286-1
Žydelis, R & Ruškytė D. 2005. Winter foraging of long-tailed ducks (Clangula hyemalis) exploiting different benthic communities in the Baltic Sea. Wilson Bulletin 117: 133–141. https://doi.org/10.1676/04-045
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