Interspecific aggression in magpies: impacts on other birds in New Zealand

Australian magpies (Gymnorhina tibicen) can be highly aggressive and many reports of them attacking other birds in New Zealand exist. Furthermore, anecdotal reports of sudden declines in bird numbers are often associated with the arrival of magpies into an area. Until now, however, no studies have attempted to determine the impact they may have on other birds in New Zealand. Here we assess (in three separate trials): (1) changes in the abundance of other birds over three years of large-scale (900 ha) magpie control, (2) if other birds avoided flying or foraging close to territorial and flocking magpies, the proportion of passing birds that were attacked and the behavioural context of those attacks, and (3) whether magpies are serious predators of nesting birds in rural ecosystems.

Author Morgan, D., Innes, J., Waas, J. and Spurr, E.
Date 2005-05-02
Year 2005
Secondary title 13th Australasian Vertebrate Pest Conference
Place published Wellington, NZ
Publisher Landcare Research
Institution University of Waikato
Pages 224-224
Region NZ
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