Do territorial and non‐breeding Australian Magpies Gymnorhina tibicen influence the local movements of rural birds in New Zealand?

摘要: Australian Magpies Gymnorhina tibicen sometimes attack and kill other birds in New Zealand. Here we assess how influence the local distribution of Zealand identify members an Magpie population that display most agonistic acts. We conducted regular observations on six territorial breeding groups three non-breeding flocks for 1 year to determine (1) if avoid flying or foraging close Magpies, (2) proportion passing are attacked (3) which social subunits aggressive. In comparison with adjacent Magpie-free control areas, significantly fewer a range species (e.g. Common Blackbird Turdus merula , Skylark Alauda arvensis Yellowhammer Emberiza citrinella ) foraged (i.e. ≤ 50 m) both flocks; were also recorded near but not flocks. Excluding Australasian Harriers ( Circus approximans : see below), only 8% within m observed being attacked. Attacks frequent when numerous occurred highest frequencies generally most. Territorial 39% Harriers. All attacks consisted victim swooped at chased; no physical contact was ever observed. Both adult male female seen attacking birds; juveniles supported adults never initiated attacks. birds, except (attacked 17% appearances). Our results suggest some and/or because they chased by sexes; however, actually small. The published apparently biased heavily towards sensational events rare. Possible reasons why discussed.