Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW, 2751, Australia.
School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, 7001, Australia.
Sci Rep. 2021 Jan 13;11(1):851. doi: 10.1038/s41598-020-79551-0.
In Australia, significant shifts in species distribution have occurred with the loss of megafauna, changes in indigenous Australian fire regime and land-use changes with European settlement. The emu, one of the last megafaunal species in Australia, has likely undergone substantial distribution changes, particularly near the east coast of Australia where urbanisation is extensive and some populations have declined. We modelled emu distribution across the continental mainland and across the Great Dividing Range region (GDR) of eastern Australia, under historical, present and future climates. We predicted shifts in emu distribution using ensemble modelling, hindcasting and forecasting distribution from current emu occurrence data. Emus have expanded their range northward into central Australia over the 6000 years modelled here. Areas west of the GDR have become more suitable since the mid-Holocene, which was unsuitable then due to high precipitation seasonality. However, the east coast of Australia has become climatically sub-optimal and will remain so for at least 50 years. The north east of NSW encompasses the range of the only listed endangered population, which now occurs at the margins of optimal climatic conditions for emus. Being at the fringe of suitable climatic conditions may put this population at higher risk of further decline from non-climatic anthropogenic disturbances e.g. depredation by introduced foxes and pigs. The limited scientific knowledge about wild emu ecology and biology currently available limits our ability to quantify these risks.
在澳大利亚，随着巨型动物的消失、澳大利亚本土火灾模式的变化以及欧洲人定居后的土地利用变化，物种分布发生了重大变化。鸸鹋是澳大利亚最后一种大型动物之一，其分布可能发生了重大变化，特别是在澳大利亚东海岸，那里城市化程度很高，一些种群已经减少。我们根据历史、现在和未来的气候，在澳大利亚大陆和大分水岭地区（GDR）模拟了鸸鹋的分布。我们使用集合模型、回溯和预测当前鸸鹋出现数据的分布来预测鸸鹋的分布变化。在模拟的 6000 年中，鸸鹋的分布向北扩展到了澳大利亚中部。从中新世开始，GDR 西部的地区变得更加适宜，因为那时降水季节性很强。然而，澳大利亚东海岸的气候已经变得不太理想，至少在 50 年内仍将如此。新南威尔士州东北部包括唯一列出的濒危种群的范围，该种群现在出现在鸸鹋最适宜的气候条件的边缘。处于适宜气候条件的边缘可能使该种群面临更高的风险，因为非气候人为干扰（例如引入的狐狸和猪的掠夺）可能会进一步减少。目前有关野生鸸鹋生态学和生物学的科学知识有限，限制了我们量化这些风险的能力。
