Are goose nesting success and lemming cycles linked Interplay between nest density and predators

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Are goose nesting success and lemming cycles
linked? Interplay between nest density and
predators

• Joël Bêty
• Gilles Gauthier
• Jean-François Giroux
• Erkki Korpimäki

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What factors determine the abundance and the
distribution of organisms?
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Direct trophic interactions
Indirect trophic interactions (e.g. trophic
cascade)
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Potential indirect interactions
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Indirect trophic interactions between rodents and
birds

• Alternative Prey Hypothesis
• (numerical and fonctional responses of
  predators)
• Nesting Association Hypothesis
• (protective association with birds of prey)

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Indirect trophic interactions between rodents and
birds

• Alternative Prey Hypothesis
• (numerical and fonctional response of predators)
• Nesting Association Hypothesis
• (protective association with birds of prey)

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LOW density
HIGH density
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Who are the actors?
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Relative importance of nest predators (1996-1999)
Goose nest attacksn 318
Success by predators (1 egg or more) n 66
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Nesting association between geese and snowy owls
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Nesting association between geese and snowy owls
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Artificial nest experiments
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Distribution of artificial nests
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Relative contribution of predator species over
one lemming cycle (range 28 to 154 attacks/year)
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In brief

• Results are consistent with the hypothesis that
  cyclic lemming populations indirectly affect the
  nesting productivity of arctic-nesting geese
• Nesting association positive effect at local
  level
• Alternative Prey Hypothesis the main mechanism
  linking lemmings and geese

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Acknowledgments

• Financial and logistic support
• NSERC (scholarship grants)
• FCAR (scholarship grants)
• Fondation Richard Bernard (scholarship)
• Société Léon-Provancher (scholarship)
• Université Laval (scholarship)
• Ducks Unlimited
• Polar Continental Shelf Project
• Canadian Wildlife Service
• Department of Indian and Northern Affairs
• Environment Canada (Arctic Goose Joint Venture)
• Pond Inlet Hunters and Trappers Association

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• Field work
• Over 35 people!
• Arnaud Béchet, Isabelle Chouinard, Diane Dauphin,
  Karine Dubreuil, Frédéric Demers, Réjean
  Deschênes, Dominique Fiset, Diane Leclerc, Denis
  Lepage, Josée Lefèbvre, Julien Mainguy, Hélène
  Massé, Stéphane Menu, Amos Ootoovak, Joasie
  Ootoovak, Sam Ootoovak, Luc Pelletier, Thomas
  Pewataluk, Gérald Picard, Nathalie Piedboeuf,
  Catherine Poussart, Stéphanie Rioux, Jean-Pierre
  Tremblay, Austin Reed, Eric Reed, Mathilde
  Renaud, Francis St-Pierre