Climate, season, and social status modulate the functional response of an efficient stalking predator: the Eurasian lynx

Authors

  • Erlend B. Nilsen,

    Corresponding author
    1. Faculty of Forestry and Wildlife Management, Hedmark University College, Evenstad, NO-2480 Koppang, Norway
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    • Present address: Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway.

  • John D. C. Linnell,

    1. Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway
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  • John Odden,

    1. Norwegian Institute for Nature Research, NO-0349 Oslo, Norway
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  • Reidar Andersen

    1. Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway
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    • Present address: Section of Natural History, Museum of Natural History and Archaeology, Norwegian University of Technology and Science, NO-7491 Trondheim, Norway.


*Correspondence author. e-mail: erlend.nilsen@nina.no

Summary

  • 1Predation plays a major role in shaping the structure and dynamics of ecological communities, and the functional response of a predator is of crucial importance to the dynamics of any predator–prey system by linking the trophic levels. For large mammals, there is a dearth of field studies documenting functional responses, and observations at low prey density are particularly scarce. Furthermore, there is a lack of understanding about how variables such as season, social status and climate modulate the functional response curves.
  • 2We analysed kill rate data collected over a 10-year period based on radio-marked lynx (Lynx lynx) mainly preying on roe deer (Capreolus capreolus) along a steep prey density gradient in south-eastern Norway.
  • 3The asymptotic kill rate was reached at a very low prey density for both solitary individuals and family groups (i.e. females with their dependent kittens), indicative of an efficient predator. This highlights the importance of understanding the interplay between predator and prey at low prey densities.
  • 4A purely prey-dependent functional response was a poor descriptor of the data, as the curve was strongly modulated by season and differences between lynx of different social status. In addition, there was a clear effect of abiotic climatic factors (indexed by the North Atlantic Oscillation) on observed kill rates in the more snow-rich portion of our study area.
  • 5Our analysis suggests that simple functional response curves might be poor descriptors of predator consumption rates in complex natural system, and that auxiliary factors are likely to induce complexity into any predator–prey systems that would not be captured by simple deterministic approaches.

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