Emu Emu Society
Journal of BirdLife Australia
RESEARCH ARTICLE

Attacks on humans by Australian Magpies (Cracticus tibicen): territoriality, brood-defence or testosterone?

Rowena M. Warne A , Darryl N. Jones A C and Lee B. Astheimer B

A Suburban Wildlife Research Group, Environmental Futures Centre, Griffith University, Nathan, Qld 4111, Australia.

B Vice-Chancellor’s Office, Deakin University, Geelong, Vic. 3217, Australia.

C Corresponding author. Email: d.jones@griffith.edu.au

Emu 110(4) 332-338 https://doi.org/10.1071/MU10027
Submitted: 22 April 2010  Accepted: 28 July 2010   Published: 9 November 2010

Abstract

Attacks on humans by Australian Magpies (Cracticus tibicen) are a significant human–wildlife conflict in Australia, especially in suburban environments. Remarkably little is known about the phenomenon. In this study, we explored three common hypotheses – territoriality, brood-defence and testosterone – as potential and non-exclusive explanations for aggression directed at people by Magpies living in suburban areas of Brisbane, south-eastern Queensland. The response of 10 pairs of aggressive Magpies to natural levels of human intrusion was compared with that of 10 non-aggressive pairs. Behavioural observations strongly supported the contention that attacks on humans resemble brood-defence and did not support an association with territoriality. The study also found no support for the suggestion that testosterone levels correlated with aggressiveness towards humans: male testosterone peaked immediately before laying and was significantly lower during the maximum period of attacks directed at people. Moreover, there were no differences in the testosterone levels of aggressive and non-aggressive male Magpies. The pattern of testosterone production over a breeding cycle closely resembled that of many other songbirds and appeared not to influence Magpie attacks on humans.

Additional keyword: wildlife attacks.


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