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PhD study, Brolga & Sarus Crane
Tim Nevard completed his PhD studying interactions between Brolga and Sarus Cranes in Australia with the Research Institute for Environment and Livelihoods, Charles Darwin University, Australia. His latest paper on Tablelands cranes and agriculture has found that foraging areas for the two species overlap, with Sarus more concentrated on fertile red soils around Atherton, Malanda and Yungaburra, and Brolgas more often to the south-west on a range of soils. Their preferred feeding sites on ploughed land and post-harvest cereal croplands are declining locally due to the spread of horticulture, especially avocadoes, but the paper concludes that both cranes are likely to be adaptable and seek out new feeding areas.
As well as investigating hybridisation between the two species, genetic work by Tim and colleagues has shown for the first time, crane migration between the Gulf of Carpentaria breeding area and the winter (or dry season) flocking area on the Atherton Tablelands, and he is expanding his work on evidence for crane migration using DNA from collected feathers. Tim is a member of the Crane Specialist Group».
Key issues
Sarolga and Sarus Crane, Atherton Tablelands 1972 (courtesy G Archibald)
There are four main themes in Tim's PhD research. Firstly, the longstanding mystery of Brolga/Sarus hybrids (‘Sarolgas)’, first sighted in 1972 (see below), but the extent of hybridisation and implications for northern Australian crane conservation were not known. Secondly, how do the species occupy the same wintering area on the Tableland, do they compete, or do they differ in their food preferences and foraging locations? Thirdly, there have been conflicts between cranes and farmers in this area, how do the conflicts arise and what can be done? And finally, how closely related are Australian Sarus to other populations in Asia – contrary to other genetic analyses, are they separate subspecies?
Study background
In 1980, crane researcher and joint founder of the International Crane Foundation George Archibald, presented a paper to the International Crane Symposium in Sapporo, Japan. In ‘Introducing the Sarolga’, he described apparent Brolga-Sarus hybrid cranes seen on the Atherton Tablelands during his 1972 trip to Australia. George Archibald's suggestion that interbreeding is recent and increasing, and may threaten the future of Brolgas in northern Australia, has been one of the intriguing themes interesting Australian crane observers and researchers ever since.
When Tim began his PhD work in 2013, the annual North Queensland Crane Count» at Tablelands crane roosts from 1997, had established that Sarus Cranes concentrated in the central Tablelands, while Brolgas concentrated further to the south-west around Ravenshoe. In 2008 preliminary results on Sarus Crane numbers and distribution from these roost counts supported the nomination and determined the boundaries for the Atherton Tablelands Key Biodiversity Area with the Sarus Crane as the trigger species. But it was unknown whether feeding areas mirrored the species' distributions based on roost counts. With the longstanding question of Sarus Crane sub-species, the genetic analyses in this study have been able for the first time, to incorporate DNA from the extinct Phillipines population to compare with samples from Australia, SE Asia and India.
TOPPapers
- Agriculture, brolgas and Australian sarus cranes on the Atherton Tablelands, Australia – abstract and references available at the link.
- Farming and cranes on the Atherton Tablelands, Australia – abstract and references available at the link.
- The sarolga: conservation implications of genetic and visual evidence for hybridization between the brolga Antigone rubicunda and the Australian sarus crane Antigone antigone gillae – abstract available at the link.
Citations
- Nevard Timothy D., Franklin Donald C., Leiper Ian, Archibald George, Garnett Stephen T. (2019) Agriculture, brolgas and Australian sarus cranes on the Atherton Tablelands, Australia. Pacific Conservation Biology. DOI: 10.1071/PC18081
- Nevard Timothy D., Leiper Ian, Archibald George, Garnett Stephen T. (2018) Farming and cranes on the Atherton Tablelands, Australia. Pacific Conservation Biology 25, 184-192.DOI: 10.1071/PC18055
- Nevard, Timothy D., Martin Haase, George Archibald, Ian Leiper, and Stephen T. Garnett. (2018). ‘The Sarolga: Conservation Implications of Genetic and Visual Evidence for Hybridization between the Brolga Antigone rubicunda and the Australian Sarus Crane Antigone antigone gillae.’ Oryx, n.d., 1-12. DOI:10.1017/S003060531800073X.
Articles and links
- The project outline is at CDU here
- Tim's field work reports, photographs and details of banded cranes are in Part 2» (Ozcranes Research).
- Tim's work at the Great Crane Project, UK
- Download ‘Introducing the Sarolga’ from Ozcranes Downloads», courtesy of Dr George Archibald
- Download GW Archibald, KSG Sundar & J. Barzen. ‘A review of the three subspecies of Sarus Cranes Grus antigone.’ J Ecol Soc (India) 16 (2003): 5-15, at Archive.org
