Population Ecology

, Volume 58, Issue 1, pp 121–133 | Cite as

Small-scale spatial and temporal variation in the demographic processes underlying the large-scale decline of eiders in the Baltic Sea

  • Markus ÖstEmail author
  • Satu Ramula
  • Andreas Lindén
  • Patrik Karell
  • Mikael Kilpi
Original article


The application of uniform conservation schemes often fails to account for small-scale spatial variation in the drivers of population decline. Demographic comparisons of imperilled populations across locations are therefore crucial for successful conservation, but progress is hampered by lack of long-term data from more than a single population. The recent large-scale decline of eider ducks (Somateria mollissima) in the Baltic Sea is ideal for determining to what extent mechanisms underlying population decline can be extrapolated over larger areas. We utilized stochastic demographic methods incorporating both environmental and sampling variation to assess small-scale spatial and temporal variation in the population dynamics of eiders at Söderskär (eastern range-margin) and Tvärminne (core breeding area), situated 130 km apart. The stochastic growth rate models accurately predicted the observed differences in the rate of decline between sites and time periods. At Söderskär, established breeder survival had by far the greatest elasticity, whereas elasticity was more evenly distributed among vital rates at Tvärminne. Although the study sites showed the single largest difference in fecundity, stochastic life table response experiment analyses revealed that reduced adult female survival at Tvärminne mainly determined the observed difference in growth rates between sites. In contrast, reduced fecundity primarily differentiated the past population increase from the present population decline at Söderskär. Our results demonstrate that different mechanisms may be associated with population decline across adjacent geographic locations, and indicate that dispersal of first-time breeders may be important for population dynamics. Safeguarding adult female survival and/or fecundity should be prioritized in management efforts.


Fecundity Population decline Population growth rate Predation Stochastic life table response experiment Survival 



We thank the numerous people participating in field work at both Söderskär and Tvärminne over the decades, particularly Martti Hario for his efforts in collecting the invaluable long-term data from Söderskär. We also thank Jukka Rintala and an anonymous reviewer for insightful comments on an earlier draft of this paper. This study was funded by the Academy of Finland (Grants 128039 to MÖ, 252577 to PK) and the Swedish Cultural Foundation in Finland (MÖ).

Compliance with ethical standards

Conflict of interest


Supplementary material

10144_2015_517_MOESM1_ESM.pdf (30 kb)
Supplementary material 1 (PDF 29 kb)
10144_2015_517_MOESM2_ESM.pdf (55 kb)
Supplementary material 2 (PDF 55 kb)


  1. Anderson MG, Ryhmer JM, Rohwer FC (1992) Philopatry, dispersal, and the genetic structure of waterfowl populations. In: Batt BDJ, Afton AD, Anderson MG, Ankney CD, Johnson DH, Kadlec JA, Krapu GL (eds) Ecology and management of breeding waterfowl. University of Minnesota Press, Minneapolis, pp 365–395Google Scholar
  2. Baillie SR, Milne H (1989) Movements of eiders Somateria mollissima on the east coast of Britain. Ibis 131:321–335CrossRefGoogle Scholar
  3. Boyd C, Brooks TM, Butchart SHM, Edgar GJ, Da Fonseca GAB, Hawkins F, Hoffmann M, Sechrest W, Stuart SN, Van Dijk PP (2008) Spatial scale and the conservation of threatened species. Conserv Lett 1:37–43CrossRefGoogle Scholar
  4. Bregnballe T, Gregersen J, Jepsen PU (2002) Development of common eider Somateria mollissima colonies in southwestern Kattegat, Denmark: Influence of predators and immigration. Danish Review of Game Biology 16:15–24Google Scholar
  5. Brook BW, Traill LW, Bradshaw CJA (2006) Minimum viable population size and global extinction risk are unrelated. Ecol Lett 9:375–382PubMedCrossRefGoogle Scholar
  6. Burnham KK, Johnson JA, Konkel B, Burnham JL (2012) Nesting common eider (Somateria mollissima) population quintuples in Northwest Greenland. Arctic 65:456–464CrossRefGoogle Scholar
  7. Caswell H (2001) Matrix population models Construction, analysis and interpretation, 2nd edn. Sinauer Associates, Inc Publishers, Sunderland, MassachusettsGoogle Scholar
  8. Caswell H (2010) Life table response experiment analysis of the stochastic growth rate. J Ecol 98:324–333CrossRefGoogle Scholar
  9. Clinchy M, Sheriff MJ, Zanette L (2013) Predator induced stress and the ecology of fear. Funct Ecol 27:56–65CrossRefGoogle Scholar
  10. Cowlishaw G, Pettifor RA, Isaac NJB (2009) High variability in patterns of population decline: the importance of local processes in species extinctions. Proc R Soc Lond B 276:63–69CrossRefGoogle Scholar
  11. Davison R, Jacquemyn H, Adriaens D, Honnay O, de Kroon H, Tuljapurkar S (2010) Demographic effects of extreme weather events on a short-lived calcareous grassland species: stochastic life table response experiments. J Ecol 98:255–267CrossRefGoogle Scholar
  12. Descamps S, Forbes MR, Gilchrist HG, Love OP, Bêty J (2011) Avian cholera, post-hatching survival and selection on hatch characteristics in a long-lived bird, the common eider Somateria mollissima. J Avian Biol 42:39–48CrossRefGoogle Scholar
  13. Ekroos J, Fox AD, Christensen TK, Petersen IK, Kilpi M, Jónsson JE, Green M, Laursen K, Cervencl A, de Boer P, Nilsson L, Meissner W, Garthe S, Öst M (2012a) Declines amongst breeding Eider Somateria mollissima numbers in the Baltic/Wadden Sea flyway. Ornis Fenn 89:81–90Google Scholar
  14. Ekroos J, Öst M, Karell P, Jaatinen K, Kilpi M (2012b) Philopatric predisposition of predation-induced ecological traps:habitat-dependent mortality of breeding eiders. Oecologia 70:979–986CrossRefGoogle Scholar
  15. Gaillard J-M, Festa-Bianchet M, Yoccoz NG (1998) Population dynamics of large herbivores: variable recruitment with constant adult survival. Trends Ecol Evol 13:58–63PubMedCrossRefGoogle Scholar
  16. Greenwood P, Harvey PH (1982) The natal and breeding dispersal of birds. Annu Rev Ecol Syst 13:1–21CrossRefGoogle Scholar
  17. Hario M, Öst M (2002) Does heavy investment in foraging implicate low food acquisition for female common eiders Somateria mollissima? Ornis Fenn 79:111–120Google Scholar
  18. Hario M, Rintala J (2006) Fledging production and population trends in Finnish common eiders (Somateria mollissima mollissima)—evidence for density dependence. Can J Zool 84:1038–1046CrossRefGoogle Scholar
  19. Hario M, Rintala J (2009) Age of first breeding in the common eider (Somateria m. mollissima) population in the northern Baltic Sea. Ornis Fenn 86:81–88Google Scholar
  20. Hario M, Rintala J (2011) Saaristolintukantojen kehitys Suomessa 1986–2010 (Summary: Population trends of the archipelago birds along the Finnish coasts during 1986-2010). Linnut Vuosikirja 2010:40–51 (in Finnish) Google Scholar
  21. Hario M, Rintala J (2014) Saaristolinnuston kehitys Suomen rannikoilla 1986–2013 (Summary: population trends of archipelago birds along Finnish coasts during 1986–2013). Linnut Vuosikirja 2013:46–53 (in Finnish) Google Scholar
  22. Hario M, Mazerolle MJ, Saurola P (2009) Survival of female common eiders Somateria m. mollissima in a declining population of the northern Baltic Sea. Oecologia 159:747–756PubMedCrossRefGoogle Scholar
  23. Hario M, Koljonen M-L, Rintala J (2012) Kin structure and choice of brood care in a common eider (Somateria m. mollissima) population. J Ornithol 153:963–973CrossRefGoogle Scholar
  24. Hollmén T (2002) Biomarkers of health and disease in common eiders Somateria mollissima in Finland. Dissertation, University of Helsinki, HelsinkiGoogle Scholar
  25. Jaatinen K, Öst M (2011) Experience attracts: the role of age in the formation of cooperative brood-rearing coalitions in eiders. Anim Behav 81:1289–1294CrossRefGoogle Scholar
  26. Jongejans E, Jorritsma-Wienk LD, Becker U, Dostal P, Milden M, de Kroon H (2010) Region versus site variation in the population dynamics of three short-lived perennials. J Ecol 98:279–289CrossRefGoogle Scholar
  27. Lande R (1993) Risks of population extinction from demographic and environmental stochasticity and random catastrophes. Am Nat 142:911–927CrossRefGoogle Scholar
  28. Lehikoinen A, Kilpi M, Öst M (2006) Winter climate affects subsequent breeding success of common eiders. Global Change Biol 12:1–11CrossRefGoogle Scholar
  29. Lehikoinen A, Christensen TK, Öst M, Kilpi M, Saurola P, Vattulainen A (2008a) Large-scale change in the sex ratio of a declining eider population. Wildl Biol 14:288–301CrossRefGoogle Scholar
  30. Lehikoinen A, Öst M, Hollmén T, Kilpi M (2008b) Does sex-specific duckling mortality contribute to male bias in adult common eiders? Condor 110:574–578CrossRefGoogle Scholar
  31. Merkel FR (2010) Evidence of recent population recovery in common eiders breeding in western Greenland. J Wildl Manage 74:1869–1874CrossRefGoogle Scholar
  32. Olea PP, Mateo-Tomás P (2014) Living in risky landscapes: delineating management units in multithreat environments for effective species conservation. J Appl Ecol 51:42–52CrossRefGoogle Scholar
  33. Öst M, Vitikainen E, Waldeck P, Sundström L, Lindström K, Hollmén T, Franson JC, Kilpi M (2005) Eider females form non-kin brood-rearing coalitions. Mol Ecol 14:3903–3908PubMedCrossRefGoogle Scholar
  34. Öst M, Smith BD, Kilpi M (2008) Social and maternal factors affecting duckling survival in eiders Somateria mollissima. J Anim Ecol 77:315–325PubMedCrossRefGoogle Scholar
  35. Öst M, Lehikoinen A, Jaatinen K, Kilpi M (2011) Causes and consequences of fine-scale breeding dispersal in a female-philopatric species. Oecologia 166:327–336PubMedCrossRefGoogle Scholar
  36. Ottwall R (2012) Ejderns och andra musselätande dykänders minskning i Östersjön. Statens Offentliga Utredningar, Rapport från Miljöforskningsberedningen (in Swedish) Google Scholar
  37. Rönkä M, Saari L, Hario M, Hänninen J, Lehikoinen E (2011) Breeding success and breeding population trends of waterfowl: implications for monitoring. Wildl Biol 17:225–239CrossRefGoogle Scholar
  38. Šidak Z (1967) Rectangular confidence regions for the means of multivariate normal distributions. J Am Stat Assoc 62:626–633Google Scholar
  39. Swennen C (1990) Dispersal and migratory movements of eiders Somateria mollissima breeding in the Netherlands. Ornis Scand 21:17–27CrossRefGoogle Scholar
  40. R Development Core Team (2013) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna.
  41. Travers M, Clinchy M, Zanette L, Boonstra R, Williams TD (2010) Indirect predator effects on clutch size and the cost of egg production. Ecol Lett 13:980–988PubMedGoogle Scholar
  42. Trivers RL, Willard DE (1973) Natural selection of parental ability to vary the sex ratio of offspring. Science 179:90–92PubMedCrossRefGoogle Scholar
  43. Tuljapurkar S, Horvitz CC, Pascarella JB (2003) The many growth rates and elasticities of populations in random environments. Am Nat 162:489–502PubMedCrossRefGoogle Scholar
  44. Union European (2008) Directive 2008/56/EC of the European Parliament and of the Council of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive). Off J Eur Union L164:19–40Google Scholar
  45. Wilson HM, Flint PL, Powell AN, Grand J, Moran CL (2012) Population ecology of breeding Pacific common eiders on the Yukon-Kuskokwim Delta, Alaska. Wildl Monogr 182:1–28CrossRefGoogle Scholar
  46. Wolfinger R, Tobias R, Sall J (1994) Computing Gaussian likelihoods and their derivatives for general linear mixed models. SIAM J Sci Comput 15:1294–1310CrossRefGoogle Scholar

Copyright information

© The Society of Population Ecology and Springer Japan 2015

Authors and Affiliations

  1. 1.Environmental and Marine Biology, Faculty of Science and EngineeringÅbo Akademi UniversityTurkuFinland
  2. 2.Aronia Coastal Zone Research TeamÅbo Akademi University and Novia University of Applied SciencesEkenäsFinland

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