Changes in the proportion of young birds in the hunting bag of Eurasian wigeon: long-term decline, but no association with climate

  • Hannu Pöysä
  • Veli-Matti Väänänen
Original Article


The proportion of first-year birds in annual wing samples provided by hunters has been used as a measure of breeding success in waterfowl. The proportion of first-year birds in the wing samples of Eurasian wigeon (Mareca penelope) from Denmark and the UK shows a long-term decline, probably reflecting a decrease in breeding success. However, previous studies report conflicting results in the relationship between variation in the proportion of first-year birds and variation in climatic conditions. We used wing data of hunter-shot Eurasian wigeon from Finland to study whether the proportion of first-year birds shows a similar long-term decline and whether between-year variation in the proportion of young is associated with variation in climatic conditions. We found a long-term decline in the proportion of first-year birds. The proportion of young also varied considerably between years, but this variation was not associated with weather or the climatic variables considered for the breeding and wintering periods. More research is needed concerning factors that affect long-term changes and annual variation in the proportion of young in the hunting bag and on the suitability of this index to measure productivity in ducks.


Age ratio Breeding success Climate Hunting bag Temperature 



The late Matti K. Pirkola did invaluable work when he organised the collection of hunter-shot duck wings in Finland during 1966–1988. Arno Salminen identified wigeon samples in the early stage and taught V-MV the secrets of identifying duck age and sex from wing samples. We would like to thank all the hunters who voluntarily supplied us with duck wings and Katja Ikonen for help in organising the wing sampling scheme 2014–2016. Tony Fox kindly helped us break the back of the problem in their analysis of factors affecting variation in age ratios of hunter-shot birds in Danish wigeon samples. Comments from two anonymous reviewers helped to improve the manuscript. We thank Stella Thompson for checking the English.


  1. Alhainen M, Väänänen V-M, Pöysä H, Ermala A (2010) Duck hunting bag in Finland—what do wing samples tell us about the species composition and age structure in a bag? Suomen Riista 56:40–47 in Finnish with English Summary Google Scholar
  2. Alisauskas RT (2002) Arctic climate, spring nutrition, and recruitment in midcontinent lesser snow geese. J Wildl Manag 66:181–183CrossRefGoogle Scholar
  3. Arzel C, Dessborn L, Pöysä H, Elmberg J, Nummi P, Sjöberg K (2014) Early springs and breeding performance in two sympatric duck species with different migration strategies. Ibis 156:288–298CrossRefGoogle Scholar
  4. Christensen TK, Fox AD (2014) Changes in age- and sex-ratios amongst samples of hunter-shot wings from common duck species in Denmark 1982–2010. Eur J Wildl Res 60:303–312CrossRefGoogle Scholar
  5. Clausen KK, Dalby L, Sunde P, Christensen TK, Egelund B, Fox AD (2013) Seasonal variation in Eurasian wigeon Anas penelope sex and age ratios from hunter-based surveys. J Ornithol 154:769–774CrossRefGoogle Scholar
  6. Dormann CF, Elith J, Bacher S, Buchmann C, Carl G, Carré G, García Marquéz JR, Gruber B, Lafourcade B, Leitão PJ, Münkemüller T, McClean C, Osborne PE, Reineking B, Schröder B, Skidmore AK, Zurell D, Lautenbach S (2013) Collinearity: a review of methods to deal with it and a simulation study evaluating their performance. Ecography 36:27–46CrossRefGoogle Scholar
  7. Elmberg J, Nummi P, Pöysä H, Sjöberg K (2003) Breeding success of sympatric dabbling ducks in relation to population density and food resources. Oikos 100:333–341CrossRefGoogle Scholar
  8. Folland CK, Knight J, Linderholm HW, Fereday D, Ineson S, Hurrell JW (2009) The summer North Atlantic Oscillation: past, present, and future. J Clim 22:1082–1103CrossRefGoogle Scholar
  9. Fox AD, Kuhlmann Clausen K, Dalby L, Christensen TK, Sunde P (2015) Age-ratio bias among hunter-based surveys of Eurasian Wigeon Anas penelope based on wing vs. field samples. Ibis 157:391–395CrossRefGoogle Scholar
  10. Fox AD, Dalby L, Christensen TK, Nagy S, Balsby TJS, Crowe O, Clausen P, Deceuninck B, Devos K, Holt CA, Hornman M, Keller V, Langendoen T, Lehikoinen A, Lorentsen S-H, Molina B, Nilsson L, Stipniece A, Svenning J-C, Wahl J (2016a) Seeking explanations for recent changes in abundance of wintering Eurasian Wigeon (Anas penelope) in northwest Europe. Ornis Fennica 93:12–25Google Scholar
  11. Fox AD, Kuhlmann Clausen K, Dalby L, Christensen TK, Sunde P (2016b) Between-year variations in sex/age ratio bias in hunter wings of EurasianWigeon (Anas penelope) compared to field samples. Ornis Fennica 93:26–30Google Scholar
  12. Freckleton RP (2002) On the misuse of residuals in ecology: regression of residuals vs. multiple regression. J Anim Ecol 71:542–545CrossRefGoogle Scholar
  13. Ganter B, Boyd H (2000) A tropical volcano, high predation pressure, and the breeding biology of arctic waterbirds: a circumpolar review of breeding failure in the summer of 1992. Arctic 53:289–305CrossRefGoogle Scholar
  14. Gardarsson A, Einarsson A (1997) Numbers and production of Eurasian wigeon in relation to conditions in a breeding area, Lake Myvatn, Iceland. J Anim Ecol 66:439–451CrossRefGoogle Scholar
  15. Gebre S, Alfredsen K (2014) Contemporary trends and future changes in freshwater ice conditions: inference from temperature indices. Hydrol Res 45:455–478CrossRefGoogle Scholar
  16. Gebre S, Boissy T, Alfredsen K (2014) Sensitivity of lake ice regimes to climate change in the Nordic region. Cryosphere 8:1589–1605CrossRefGoogle Scholar
  17. Guillemain M, Bertout JM, Christensen TK, Pöysä H, Väänänen VM, Triplet P, Schricke V, Fox AD (2010) How many juvenile teal Anas crecca reach the wintering grounds ? Flyway-scale survival rate inferred from wing age-ratios. J Ornithol 151:51–60CrossRefGoogle Scholar
  18. Guillemain M, Fox AD, Pöysä H, Väänänen V-M, Christensen TK, Triplet P, Schricke V, Korner-Nievergelt F (2013) Autumn survival inferred from wing age ratios: wigeon juvenile survival half that of adults at best? J Ornithol 154:351–358CrossRefGoogle Scholar
  19. Guillemain M, Aubry F, Folliot B, Caizergues A (2016) Duck hunting bag estimates for the 2013-14 season in France. Wildfowl 66:126–141Google Scholar
  20. Hagemeijer EJM, Blair MJ (eds) (1997) The EBCC atlas of European breeding birds: their distribution and abundance. T & AD Poyser, LondonGoogle Scholar
  21. Hepp GR, Blohm RJ, Reynolds RE, Hines JE, Nichols JD (1986) Physiological condition of autumn-banded mallards and its relationship to hunting vulnerability. J Wildl Manag 50:177–183CrossRefGoogle Scholar
  22. Hurrell JW, Deser C (2010) North Atlantic climate variability: the role of the North Atlantic Oscillation. J Mar Syst 79:231–244CrossRefGoogle Scholar
  23. Hurrell JW, Kushnir Y, Ottersen G, Visbeck M (2003) An overview of the North Atlantic Oscillation. Geophys Monogr Ser 134:1–35Google Scholar
  24. Iler AM, Inoye DW, Schmidt NM, Høye TT (2017) Detrending phenological time series improves climate—phenology analyses and reveals evidence of plasticity. Ecology 93:647–655CrossRefGoogle Scholar
  25. Koskimies J, Lahti L (1964) Cold-hardiness of the newly hatched young in relation to ecology and distribution in the species of European ducks. Auk 81:281–307CrossRefGoogle Scholar
  26. Kucharski F, Molteni F, Bracco A (2006) Decadal interactions between the western tropical Pacific and the North Atlantic Oscillation. Clim Dyn 26:79–91CrossRefGoogle Scholar
  27. Lehikoinen A, Jaatinen K (2012) Delayed autumn migration in northern European waterfowl. J Ornithol 153:563–570CrossRefGoogle Scholar
  28. Lehikoinen A, Rintala J, Lammi E, Pöysä H (2016) Habitat-specific population trajectories in boreal waterbirds: alarming trends and bioindicators for wetlands. Anim Conserv 19:88–95CrossRefGoogle Scholar
  29. Lindström J, Forchhammer MC (2010) Time-series analyses. In: Møller AP, Fiedler W, Berthold P (eds) Effects of climate change on birds. Oxford University Press, Oxford, pp 57–66Google Scholar
  30. Mitchell C, Fox AD, Harradine J, Clausager I (2008) Measures of annual breeding success among Eurasian Wigeon Anas penelope. Bird Study 55:43–51CrossRefGoogle Scholar
  31. Newton I (1998) Population limitation in birds. Academic Press, LondonGoogle Scholar
  32. Patterson IJ, Hearn RD (2006) Month to month changes in age ratio and brood size in pink-footed geese Anser brachyrhynchus in autumn. Ardea 94:175–183Google Scholar
  33. Pirkola MK, Lindén H (1972) Results of duck wing collection surveys in Finland 1969 and 1970. Suomen Riista 24:97–106 in Finnish with English Summary Google Scholar
  34. Pöysä H, Väänänen V-M (2014) Drivers of breeding numbers in a long-distance migrant, the Garganey (Anas querquedula): effects of climate and hunting pressure. J Ornithol 155:679–687CrossRefGoogle Scholar
  35. Pöysä H, Rintala J, Lehikoinen A, Väisänen RA (2013) The importance of hunting pressure, habitat preference and life history for population trends of breeding waterbirds in Finland. Eur J Wildl Res 59:245–256CrossRefGoogle Scholar
  36. Pöysä H, Elmberg J, Gunnarsson G, Holopainen S, Nummi P, Sjöberg K (2017a) Habitat associations and habitat change: seeking explanation for population decline in breeding Eurasian wigeon Anas penelope. Hydrobiologia 785:207–217CrossRefGoogle Scholar
  37. Pöysä H, Elmberg J, Gunnarsson G, Holopainen S, Nummi P, Sjöberg K (2017b) Recovering whooper swans do not cause a decline in Eurasian wigeon via their grazing impact on habitat. J Ornithol.
  38. Sæther B-E, Grøtan V, Engen S, Coulson T, Grant PR, Visser ME, Brommer JE, Rosemary Grant B, Gustafsson L, Hatchwell BJ, Jerstad K, Karell P, Pietiäinen H, Roulin A, Røstad OW, Weimerskirch H (2016) Demographic routes to variability and regulation in bird populations. Nat Commun 7:12001. CrossRefPubMedPubMedCentralGoogle Scholar
  39. Saurola P, Valkama J, Velmala W (2013) The Finnish bird ringing atlas. Vol 1. Helsinki, Finnish Museum of Natural History and Ministry of EnvironmentGoogle Scholar
  40. Scott DA, Rose PM (1996) Atlas of Anatidae populations in Africa and Western Eurasia. Wetlands International Publication No. 14. Wetlands International, WageningenGoogle Scholar
  41. Summers RW, Underhill LG, Syroechkovski EE (1998) The breeding productivity of dark-bellied brent geese and curlew sandpipers in relation to changes in the numbers of arctic foxes and lemmings on the Taimyr Peninsula, Siberia. Ecography 21:573–580CrossRefGoogle Scholar
  42. Trinder MN, Hassell D, Votier S (2009) Reproductive performance in arctic-nesting geese is influenced by environmental conditions during the wintering, breeding and migration seasons. Oikos 1118:1093–1101CrossRefGoogle Scholar
  43. Väänänen V-M (2001) Hunting disturbance and the timing of autumn migration in Anas species. Wildl Biol 7:3–9Google Scholar
  44. Viksne J, Svazas S, Czajkowski A, Janaus M, Mischenko A, Kozulin A, Kuresoo A, Serebryakov V (2010) Atlas of duck populations in Eastern Europe. Akstis, VilnusGoogle Scholar
  45. White TCR (2008) The role of food, weather and climate in limiting the abundance of animals. Biol Rev 83:227–248CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Management and Production of Renewable ResourcesNatural Resources Institute FinlandJoensuuFinland
  2. 2.Department of Forest SciencesUniversity of HelsinkiHelsinkiFinland

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