ClimateWatch

An initiative of Earthwatch Institute

Australian Magpie

Thursday 27 May, 2010

Most people know the Australian Magpie, an infamous black and white bird well-known for swooping passers-by during its breeding season. In fact, about 9-12% of magpies will swoop aggressively and are nearly all males!

The Australian Magpie is found throughout most of Australia, except in very dense forests and arid deserts. Throughout its range, there have been some observed differences in their breeding, but we only know some of the details...

Overseas, several studies have indicated that climate change is influencing the timing of breeding in many species of birds; with the observed warmer conditions in recent years, birds are typically breeding earlier. However in Australia, there is relatively little published research on the biological effects of climate change on Australian species.

There is one paper on the Australian Magpie that suggests its breeding changes with changing climate. This paper by Heather Gibbs (see reference list below) describes the Magpie's breeding responses to altitude, latitude and the Southern Oscillation Index (SOI, an integrated measure of climate). The Magpie is shown to breed later in the year as altitude (above 250m in elevation) increases, with breeding being 2.7 - 3.9 days later for every 100 metres of altitude increase. For latitude, the amount of breeding records for the Magpie increased from north to south, and the breeding season in southern Australia was slightly later than in northern Australia. As altitude and latitude provide a natural temperature gradient, these results can be used to predict the likely effects of future climate warming. Thus, with the predicted temperature increases expected under climate change, the breeding patterns of the Magpie could therefore change.

However scientists need more data to further investigate how the Magpie may respond to climate change. Some results from the paper by Gibbs compared how the SOI affects the Magpie's breeding. They suggested that earlier and more breeding occurred when SOI values indicated colder, wetter conditions, which is the opposite response to the altitude and latitude results above. This suggests that for some regions rainfall, or a combination of temperature and rainfall, is more important than temperature alone in influencing the Magpie's breeding.

Therefore, we need your data to help scientists understand how climate change may affect the Magpie.  As we enter into winter, keep a look out for when it begins its breeding activity. If you haven't already, register as a ClimateWatcher today, then simply record when and where you see the Magpie and help us better understand this renowned species.


References:
Chambers, L. E., Hughes, L., and Weston, M. A. (2005). Climate change and its impact on Australia's avifauna. Emu 105, 1-20.

Crick, H. Q. P., and Sparks, T. H. (1999). Climate change related to egglaying trends. Nature 399, 423-424.

Crick, H. Q. P., Dudley, C., Glue, D. E., and Thomson, D. L. (1997). UK birds are laying eggs earlier. Nature 388, 526.

Gibbs, H. (2007). Climatic variation and breeding in the Australian Magpie (Gymnorhina tibicen): a case study using existing data. Emu 107, 284 - 293.

Hughes, L. (2003). Climate change and Australia: trends, projections and impacts. Austral Ecology 28, 423-443.