Effect of corvid removal on reproduction of willow ptarmigan and black grouse

  • Published source details Parker H. (1984) Effect of corvid removal on reproduction of willow ptarmigan and black grouse. Journal of Wildlife Management, 48, 1197-1205.


This study is summarised as evidence for the following.

Action Category

Control avian predators on islands

Action Link
Bird Conservation
  1. Control avian predators on islands

    A controlled study on Karlsøy Island (7.7 km2), Norway, in 1978-81 (Parker 1984), found that removing hooded crows Corvus cornix and ravens Corvus corax from an experimental area did not decrease predation of black grouse Tetrao tetrix nests, compared to control areas (49 nests studied). Predation of willow ptarmigan Lagopus lagopus nests was lower in the first year of the experiment (21 nests studied) but not in the next three (total of 214 nests). The author suggests that compensatory predation by ermine Mustela erminea may have prevented corvid removal from having an effect. Corvids were removed by poisoning with alpha-chloralose-treated eggs and shooting.


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