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Niels Martin Schmidt

Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark. Niels Martin Schmidt. From Jacobsen (2000). Wader population development. Most wader populations are declining in Denmark, and in Europe in general. Wader population conservation.

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Niels Martin Schmidt

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  1. Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark Niels Martin Schmidt

  2. From Jacobsen (2000) Wader population development • Most wader populations are declining in Denmark, and in Europe in general

  3. Wader population conservation • Large efforts are being invested in reversing this trend=> mainly focused on wet grassland management • Waders also respond strongly to winter severity • Relative importance of grassland management and winter severity

  4. Lapwing Redshank Avocet Ringed plover Oystercatcher The Klydesø reserve • Area of national interest as wader breeding ground • Reclaimed from sea in 1945=> Situated below sea-level=> Large succesional changes=> Detoriation of costal meadow as wader breeding ground

  5. Winter flooding Grazing Population development in the Klydesø reserve

  6. Management implements • Cattle grazing (app. one steer per ha, 38 - 270 ha) • Winter flooding (app. 115 ha shallow water)Expected effects = more breeding and foraging habitats • Fox exclusionExpected effect = less predation on nests

  7. Winter severity • Proxy of winter severity: NAO winter state • Expected effects of mild winters (high NAO) • Improved survival when migrating and when on winter grounds • Early onset of breeding in years following mild winters • Changes in food availability on tidal flats

  8. Population models • Autoregressive analyses • Most parsimonoius model selected by AICc Nt = Nt-1 Nt-2 GRAZING WINTER-FLOODING NAO

  9. Waders, management and climate

  10. Lapwings and winter severity

  11. Conclusions • Management implements did result in increased (most) wader breeding pairs • Multi-lateral conservation approach needed for ensure coastal meadow species diversity • Winter severity may be more important when management effort is constant

  12. The Lapwing paradox • Where do the lapwings come from? • High predation pressure on nests (c. 90%)=> too low production of young to maintain population size

  13. The Lapwing paradox • Underestimation of production of young? • Attract birds from other (declining) population? • Production of young in arable areas, e.g. cereals?

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