Australasian Science: Australia's authority on science since 1938

Exclusive articles for subscribers

By Stephen Luntz

More than a dozen Browse articles for subscribers only.

The full text of this article can be purchased from Informit.

Why Do Magpies Attack?
A study by Griffith University’s Suburban Wildlife Research Group has determined that magpie swooping behaviour is a form of brood defence designed to scare off predators coming after their young.

The finding, published in the journal Emu, was not unexpected although alternative theories have been raised. However, the research raises a new question – why do magpies only swoop in urban areas or where they have become habituated to humans?

Other theories to explain swooping include territorial defence and testosterone. Both may have arisen because almost all attacks come from the male magpie, although females have occasionally been observed joining in when their mate begins an attack.

However, A/Prof Jones found that testosterone levels peak prior to the laying of eggs, whereas virtually all attacks occur while the young are in the nest. Moreover, Jones compared the behaviour of magpies that had been reported to authorities as dangerous with those that had displayed no such aggression. He found no correlation with testosterone.

“Magpies are ridiculously territorial, defending their territory all year round, while other birds usually only do so during the mating season,” Jones says. However, he considers the fact that the attacks occur over such a short part of the year is a giveaway that the behaviour...

The full text of this article can be purchased from Informit.