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
+ Author Affiliations
- Author Affiliations

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.


References

Adams, C. E., Lindsey, K. J., and Ash, S. J. (2006). ‘Urban Wildlife Management.’ (Taylor and Francis: Boca Raton, FL.)

Bonier, F., Martin, P. R., Sheldon, K. S., Jensen, J. P., Folz, S. L., and Wingfield, J. C. (2006). Sex-specific consequences of life in the city. Behavioral Ecology 18, 121–129.
Sex-specific consequences of life in the city.CrossRef |

Brown, E. B., and Veltman, C. J. (1987). Ethogram of the Australian Magpie (Gymnorhina tibicen) in comparison to other Cracticidae. Ethology 76, 309–333.
Ethogram of the Australian Magpie (Gymnorhina tibicen) in comparison to other Cracticidae.CrossRef |

Brown, E. D., Farabaugh, S. M., and Hughes, J. M. (1993). A test of the centre-edge hypotheses in a permanently territorial songbird, the Australian Magpie, Gymnorhina tibicen. Animal Behaviour 45, 814–816.
A test of the centre-edge hypotheses in a permanently territorial songbird, the Australian Magpie, Gymnorhina tibicen.CrossRef |

Buttemer, W. A., and Astheimer, L. B. (2000). Testosterone does not effect metabolic rate or blood parasite load in captive White-plumed Honeyeaters Lichenostomus pencillatis. Journal of Avian Biology 31, 479–488.
Testosterone does not effect metabolic rate or blood parasite load in captive White-plumed Honeyeaters Lichenostomus pencillatis.CrossRef |

Carrick, R. (1972). Population ecology of the Australian Black-backed Magpie, Royal Penguin and Silver Gull. United States Department of Interior Wildlife Research Report 2, 41–99.

Catterall, C. P. (2004). Birds, garden plants and bushlots: where good intentions meet unexpected results. In ‘Urban Wildlife: More than Meets the Eye’. (Eds D. Lunney and S. Burgin.) pp. 21–31. (Royal Zoological Society of New South Wales: Sydney.)

Chace, J. F., and Walsh, J. J. (2006). Urban effects on native avifauna: a review. Landscape and Urban Planning 75, 143–154.

Cilento, N. J., and Jones, D. N. (1999). Aggression towards humans in Australian Magpies: nest defence or territorial behaviour. Emu 99, 85–90.
Aggression towards humans in Australian Magpies: nest defence or territorial behaviour.CrossRef |

Conover, M. L. (2001). ‘Resolving Human–Wildlife Conflicts: The Science of Wildlife Damage Management.’ (CRC Press: Logan, UT.)

Curio, E. (1993). Proximate and developmental aspects of antipredator behaviour. Advances in the Study of Behaviour 22, 135–238.
Proximate and developmental aspects of antipredator behaviour.CrossRef |

Decker, D. J., and Chase, L. C. (1999). Human dimensions of living with wildlife – a management challenge for the 21st century. Wildlife Society Bulletin 25, 788–795.

Dufty, A. M. (1989). Testosterone and survival: a cost of aggressiveness? Hormones and Behavior 23, 185–193.
Testosterone and survival: a cost of aggressiveness?CrossRef | 1:CAS:528:DyaL1MXkslGisbs%3D&md5=371d54de3ad82464079118da0cb6d903CAS | 2744737PubMed |

Farabaugh, S. M., Brown, E. D., and Hughes, J. M. (1992). Cooperative territorial defence in the Australian Magpie, Gymnorhina tibicen (Passeriformes, Cracticidae), a group-living songbird. Ethology 92, 283–292.
Cooperative territorial defence in the Australian Magpie, Gymnorhina tibicen (Passeriformes, Cracticidae), a group-living songbird.CrossRef |

Harding, C. H., and Follett, B. K. (1979). Hormone changes triggered by aggression in a natural population of Blackbirds. Science 203, 918–920.
Hormone changes triggered by aggression in a natural population of Blackbirds.CrossRef | 1:CAS:528:DyaE1MXhtlGgtrs%3D&md5=6bc0e76c3d641a560e5bc68b659fc0c3CAS | 570304PubMed |

Hau, M., Wikelski, M., Soma, K. K., and Wingfield, J. C. (2000). Testosterone and year-round aggression in a tropical bird. General and Comparative Endocrinology 117, 20–33.
Testosterone and year-round aggression in a tropical bird.CrossRef | 1:CAS:528:DC%2BD3cXosFWj&md5=b4f45fad3f3d86c4698e0ff690c02f1dCAS | 10620421PubMed |

Hinde, R. A. (1956). The biological significance of territories of birds. Ibis 98, 340–369.
The biological significance of territories of birds.CrossRef |

Horsburgh, B. J., Stark, D. J., and Harrison, J. D. (1992). Ocular injuries caused by magpie. Medical Journal of Australia 157, 756–759.
| 1:STN:280:DyaK3s%2Fos1Gntg%3D%3D&md5=89ceaa0e47aff7fba9a6f27e59504d6bCAS | 1454001PubMed |

Jones, D. N. (2002). ‘Magpie Alert: Learning to Live with a Wild Neighbour.’ (University of New South Wales Press: Sydney.)

Jones, D. N. (2003). Contemporary urban ecology: the view from the Antipodes. In ‘Ecosystems and Sustainable Development IV’. (Eds E. Tiezzi, C. Brebbia and J. Uso.) pp. 745–753. (WIT Press: Southhampton, UK.)

Jones, D. N. (2008). Wildlife management in the extreme: managing magpies and mothers in a suburban environment. In ‘Too Close for Comfort: Contentious Issues in Human–Wildlife Encounters’. (Eds D. Lunney, A. Munn and W. Meikle.) pp. 9–14. (Royal Zoological Society of New South Wales: Sydney.)

Jones, D. N., and Nealson, T. (2003). Management of aggressive Australian Magpies by translocation. Wildlife Research 30, 167–177.
Management of aggressive Australian Magpies by translocation.CrossRef |

Jones, D. N., and Thomas, L. K. (1999). Attacks on humans by Australian Magpies: management of an extreme suburban human–wildlife conflict. Wildlife Society Bulletin 27, 473–478.

Jones, L., Darroch, R. K., Gilding, J., and Bennett, D. H. (1980). A review of seasonal and ecological factors in Australian Magpie attacks on people. Bird Behaviour 2, 113–117.

Klopfer, P. H. (1969). ‘Habitats and Territories: A Study of the Use of Space by Animals.’ (Basic Books: New York.)

Knight, R. L., Grout, D. J., and Temple, S. A. (1987). Nest-defence behaviour of the American Crow in urban and rural areas. Condor 89, 175–177.
Nest-defence behaviour of the American Crow in urban and rural areas.CrossRef |

Low, T. (2002). ‘The New Nature.’ (Viking: Melbourne.)

Martin, P., and Bateson, P. (1993). ‘Measuring Behaviour.’ (Cambridge University Press: Cambridge, UK.)

Marzluff, J. M. (2001). Worldwide urbanization and its effects on birds. In ‘Avian Conservation in an Urbanizing World’. (Eds J. Marzluff, R. Bowman and R. Donnelly.) pp. 19–42. (Kluwer: Norwell, WA, USA.)

Marzluff, J. M. (2010). Lasting recognition of threatening people by wild American Crows. Animal Behaviour 79, 699–707.
Lasting recognition of threatening people by wild American Crows.CrossRef |

Marzluff, J. M., Bowman, R., and Donnelly, R. E. (2001). A histrorical perspective on urban bird research: trends, terms and approaches. In ‘Avian Conservation in an Urbanizing World’. (Eds J. Marzluff, R. Bowman and R. Donnelly.) pp. 1–18. (Kluwer: Norwell, MA.)

McDonald, P. W., Buttemer, W. A., and Astheimer, L. B. (2001). The influence of testosterone on territorial defence and parental behavior in male free-living Rufous Whistlers, Pachycephala rufiventris. Hormones and Behavior 39, 185–194.
The influence of testosterone on territorial defence and parental behavior in male free-living Rufous Whistlers, Pachycephala rufiventris.CrossRef | 1:CAS:528:DC%2BD3MXivFakt7o%3D&md5=b715b08fe40724219fb0596fdab1698eCAS | 11300709PubMed |

McLean, I. G., and Rhodes, G. (1991). Enemy recognition and response in birds. In ‘Current Ornithology’. (Ed. D. Power.) pp. 173–211. (Plenum Press: New York.)

Montgomerie, R. D., and Weatherhead, P. J. (1988). Risks and rewards of nest defence by parental birds. Quarterly Review of Biology 63, 167–187.
Risks and rewards of nest defence by parental birds.CrossRef |

O’Leary, R., and Jones, D. N. (2006). The use of supplementary foods by Australian Magpies Gymnorhina tibicen: implications for wildlife feeding in suburban environments. Austral Ecology 31, 208–216.
The use of supplementary foods by Australian Magpies Gymnorhina tibicen: implications for wildlife feeding in suburban environments.CrossRef |

Ricklefs, R. E. (1969). An analysis of nestling mortality in birds. Smithsonian Contributions to Zoology 9, 1–48.

Robinson, A. (1956). The annual reproductive cycle of the Magpie, Gymnorhina dorsalis (Campbell), in south western Australia. Emu 56, 233–336.
The annual reproductive cycle of the Magpie, Gymnorhina dorsalis (Campbell), in south western Australia.CrossRef |

Rollinson, D. J. (2003). Synanthropy in the Australian Magpie: a comparison of urban and rural populations in south-eastern Queensland, Australia. Ph.D. Thesis, Griffith University, Brisbane, Qld.

Rollinson, D. J., and Jones, D. N. (2002). Variation in breeding parameters of the Australian Magpie Gymnorhina tibicen in suburban and rural environments. Urban Ecosystems 6, 257–269.
Variation in breeding parameters of the Australian Magpie Gymnorhina tibicen in suburban and rural environments.CrossRef |

Rollinson, D. J., and Jones, D. N. (2006). Tolerance of Australian Magpie Gymnorhina tibicen towards human: a comparison along an urban gradient. Australian Field Ornithology 23, 29–35.

Schmidt, L. G., Bradshaw, S. D., and Follett, B. K. (1991). Plasma levels of leutinizing hormnone and androgens in relation to age and breeding status among cooperatively breeding Australian Magpies (Gymnorhina tibicen Latham). General and Comparative Endocrinology 83, 48–55.
Plasma levels of leutinizing hormnone and androgens in relation to age and breeding status among cooperatively breeding Australian Magpies (Gymnorhina tibicen Latham).CrossRef | 1:CAS:528:DyaK3MXkt1KntbY%3D&md5=2da2e02f3aebc9125763f754fe60c5ccCAS | 1879671PubMed |

Thomas, L. K., and Jones, D. N. (1999). Management options for a human–wildlife conflict: Australian Magpie attacks on humans. Human Dimensions of Wildlife 4, 93–95.

Vleck, C. M., and Brown, J. L. (1999). Testosterone and social and reproductive behaviour in Aphelocoma jays. Animal Behaviour 58, 943–951.
Testosterone and social and reproductive behaviour in Aphelocoma jays.CrossRef | 10564596PubMed |

Walraven, E. (1990). ‘Taronga Zoo’s Guide to the Care of Urban Wildlife.’ (Allen and Unwin: Sydney.)

Warne, R. M. (2001). Why do Magpies attack? Exploring mechanisms and functional explanations for Magpie attacks towards humans. B.Sc.(Hons) Thesis, Griffith University, Brisbane, Qld.

Warne, R. M., and Jones, D. N. (2003). Evidence for target specificity in attacks by Australian Magpies on humans. Wildlife Research 30, 265–267.
Evidence for target specificity in attacks by Australian Magpies on humans.CrossRef |

Wingfield, J. C., and Farner, D. S. (1993). Endocrinology of reproduction in wild species. In ‘Avian Biology. Vol. 9’. (Eds D. Farner, J. King and K. Parkes.) pp. 163–327. (Academic Press: New York.)

Wingfield, J. C., and Silverin, B. (2002). Ecophysiological studies of hormone–behavior relations in birds. In ‘Hormones, Brain and Behavior’. (Eds D. W. Pfaff, A. P. Arnold, A. M. Etgen, S. E. Fahrbach and R. T. Rubin.) pp. 587–647. (Elsevier: New San Diego, CA.)

Wingfield, J. C., and Soma, K. K. (2002). Spring and autumn territoriality in Song Sparrows: same behavior, different mechanisms? Integrative and Comparative Biology 42, 11–20.
Spring and autumn territoriality in Song Sparrows: same behavior, different mechanisms?CrossRef |

Wingfield, J. C., Hegner, R. E., Dufty, A. M., and Ball, G. F. (1990). The ‘Challenge Hypothesis’: theoretical implications for patterns of testosterone secretion, mating systems and breeding strategies. American Naturalist 136, 829–846.
The ‘Challenge Hypothesis’: theoretical implications for patterns of testosterone secretion, mating systems and breeding strategies.CrossRef |

Wingfield, J. C., Jacobs, J. D., and Hillgarth, N. (1997). Ecological constraints and the evolution of hormone–behaviour interrelationships. Annals of the New York Academy of Science 807, 22–41.
Ecological constraints and the evolution of hormone–behaviour interrelationships.CrossRef | 1:CAS:528:DyaK2sXks1aku7o%3D&md5=25c7fab2298d15164c13d32426c18951CAS |

Zar, J. H. (1996). ‘Biostatistical Analysis.’ 3rd edn. (Prentice-Hall: New York.)


Export Citation Cited By (1)

View Altmetrics