Examining the life history of Banded Stilts

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RESEARCH AREA
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This week’s featured research article has just been published in Conservation Biology and examines long-distance flights and high-risk breeding by Banded Stilts on desert salt lakes in central Australia. Based on data from satellite telemetry, frequent aerial surveys, and analyses of satellite imagery, to provide a current and historic perspective on continent wide breeding opportunities, this research challenges the traditional view of the species’ life history. Previous work suggests that long-lived individuals likely bred once or twice per decade and only after infrequent large flood events. In contrast, the researchers found a high frequency of nesting attempts, often associated with minor flood events. This result suggests this nomadic desert shorebird may attempt to exploit not only large infrequent floods but also much smaller more frequent events, when the chances of breeding success are lower. Furthermore, the scale and rapidity of flights following distant flooding suggests major energetic investment by these individuals, startling physiological preparation and high individual risk taking. Female Banded Stilts flew hundreds of kilometers in response to distant rainfall and then within days produced the equivalent of half their body mass in eggs that had only a 30% chance of hatching and much lower probability of fledging. These rapid long-distance flights toward temporarily flooded lakes indicate that Banded Stilts are capable of exploiting short-lived opportunities on salt lakes across the Australian continent. Thus, individuals may access small to moderate flood events at sites thousands of kilometres distant from coastal wetlands that they inhabit between inland rainfall events. The finding that Banded Stilts can respond to and successfully breed after flood events in which just a fraction of the lake surface area is covered in water, is transformative to the understanding of the population dynamics of the species. As such, smaller-magnitude, more frequent resource pulses across a dynamic desert landscape may be equally or more important than large infrequent ones. The researchers conclude that this is a key consideration for conservation planning for Banded Stilts, specifically around the possible effect of changes to salt lake filling regimes from anthropogenic activity. The article can be downloaded here (or email jennie.fluin@sa.gov.au for a copy).