"Freshwater killer whales": beaching behavior of an alien fish to hunt land birds

PLoS One. 2012;7(12):e50840. doi: 10.1371/journal.pone.0050840. Epub 2012 Dec 5.

Abstract

The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ(13)C and δ(15)N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / physiology*
  • Birds / physiology*
  • Catfishes / physiology*
  • Diet
  • Europe
  • Fresh Water*
  • Introduced Species*
  • Isotope Labeling
  • Predatory Behavior / physiology*
  • Whale, Killer / physiology*

Grant support

JC was supported by an “ERG Marie Curie” grant (PERG08-GA-2010- 276969) in the lab EDB, part of the “Laboratoire d”Excellence (LABEX) entitled TULIP (ANR -10-LABX-41). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.