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<\/a><\/p>\nThe red knot (Calidris canutus), juvenile, near Gourinet, Brittany, France. Image credit: Stephan Sprinz \/ CC BY 4.0.<\/p>\n
\u201cShorebirds are rare in the fossil record, so finding so many in one cave (Blanche Cave) was a surprise,\u201d said Flinders University Ph.D. candidate Karl Lenser.<\/p>\n
\u201cThis shows that the wetlands and mudflats, where birds like plovers, sandpipers and snipes feed, were much more common in the region during the last Ice Age.\u201d<\/p>\n
Climate change and shrinking habitat are causing living shorebird populations in Australia to fall.<\/p>\n
Understanding how these species responded to past climate change may be key to predicting how populations will be affected in the future.<\/p>\n
Lenser and his colleagues were particularly puzzled by the fossils of one bird.<\/p>\n
The plains-wanderer \u2014 a small, endangered bird which is found predominantly in small populations in Victoria and New South Wales \u2014 was one of the most common species identified in the study.<\/p>\n
Over half of the nearly 300 bones examined by the authors were identified as plains-wanderers.<\/p>\n
\u201cLiving plains-wanderers are now very selective about their habitat, but other fossils from Naracoorte show that the area was probably a woodland \u2026 a far cry from the treeless open grasslands plains-wanderers inhabit today,\u201d Lenser said.<\/p>\n
Naracoorte is the only fossil site in Australia where plains-wanderers are found in such high numbers, suggesting that events in the last 14,000 years caused a large decline in populations of this intriguing bird.<\/p>\n
This decline was associated with the plains-wanderer becoming limited to a narrower range of habitats where trees are absent, rather different to the woodlands it occupied during the last hundred thousand years.<\/p>\n
\u201cThis sample of shorebirds is also extra special as it documents migratory species that annually fly from the northern hemisphere to spend the boreal winter in Australia,\u201d said Flinders University\u2019s Dr. Trevor Worthy.<\/p>\n
\u201cThese include three species of sandpipers in the genus Calidris<\/a> and the Latham\u2019s snipe (Gallinago hardwickii)<\/a>.\u201d<\/p>\n \u201cAlso common in the fossil assemblage is the double-banded plover which migrates from Australia to New Zealand to breed.\u201d<\/p>\n \u201cTwo birds were less than a year old indicating that they had flown as fledglings the 2,000 km distance from New Zealand only to be captured by an owl near Blanche Cave at Naracoorte,\u201d Dr. Worthy said.<\/p>\n \u201cThere is still a lot we don\u2019t know about birds in Australia during the last Ice Age, but fossils from caves like those at Naracoorte are helping to fill this gap,\u201d Lenser added.<\/p>\n \u201cThe Naracoorte Caves preserves a half million-year record of biodiversity in southeast South Australia,\u201d said Adelaide University\u2019s Dr. Liz Reed.<\/p>\n \u201cAs this study clearly demonstrates, the caves provide a window into pre-European landscapes and yield information relevant to the conservation of threatened species today.\u201d<\/p>\n \u201cVisitors to Naracoorte Caves can view the excavations and learn more about the science of South Australia\u2019s only World Heritage Area.\u201d<\/p>\n