Green Ken, Caley Peter, Baker Monika, Dreyer David, Wallace Jesse, Warrant Eric
Australian National University College of Asia and the Pacific Canberra ACT 2601 Australia.
Data 61, Commonwealth Scientific and Industrial Research Organisation Canberra ACT 2601 Australia.
Aust Entomol. 2021 Feb;60(1):66-81. doi: 10.1111/aen.12517. Epub 2020 Dec 18.
The Bogong moth is well known for its remarkable long-distance migration - a return journey from the plains of southeast Australia to the Australian Alps - as well as for its cultural significance for Indigenous Australians. Each spring, as many as four billion moths are estimated to arrive in the Australian Alps to aestivate in cool mountain caves and in boulder fields, bringing with them a massive annual influx of energy and nutrients critical for the health of the alpine ecosystem. However, a massive decline in moths present at their aestivation sites has occurred over the past 3 years, with only a few individuals present where hundreds of thousands could earlier be found. In order to understand the possible sources of decline, we analysed historical records of Bogong moth numbers at aestivation sites in the Australian Alps, including observations on Mt. Gingera (NSW) in the early 1950s, observations from 1980 onwards in the Snowy Mountains (NSW) and an almost-unbroken series of observations each summer over the past 53 years in three caves at different elevations on Mt. Buffalo (Victoria). This analysis shows that moth numbers were probably steady from 1951 until about 1980, fluctuated and slowly fell from then until 2016 and dramatically crashed in 2017. In the Murray-Darling Basin, the main winter breeding ground of Bogong moths, changes in farming practices, such as increasing land clearing for crops (which has removed around a quarter of a billion moths annually from the mountains compared to pre-European levels), has probably driven some of the decline in Bogong moth numbers observed from 1980 to 2016. The impact of insecticide remains unclear and is in urgent need of further study. Even though we found little evidence that increasing global temperatures per se are responsible for the Bogong moth decline, the Australian climate has nonetheless become drier and warmer over past decades, possibly hampering the survival of immature stages in the breeding areas and confining adult aestivation to gradually higher elevations. The crash in moth numbers from 2017 is most likely due to the recent severe drought in the moth's breeding grounds.
博贡蛾以其非凡的长途迁徙而闻名——从澳大利亚东南部平原返回澳大利亚阿尔卑斯山的旅程——以及对澳大利亚原住民的文化意义。每年春天，估计多达40亿只蛾子会抵达澳大利亚阿尔卑斯山，在凉爽的山洞和巨石场中夏眠，为高山生态系统的健康带来每年大量的能量和营养物质涌入。然而，在过去3年里，它们夏眠地点的蛾子数量大幅下降，在以前能发现数十万只蛾子的地方，现在只剩下几只。为了了解数量下降的可能原因，我们分析了澳大利亚阿尔卑斯山夏眠地点博贡蛾数量的历史记录，包括20世纪50年代初在金杰拉山（新南威尔士州）的观测、1980年起在雪山（新南威尔士州）的观测，以及过去53年每年夏天在布法罗山（维多利亚州）不同海拔的三个洞穴进行的几乎不间断的观测。分析表明，蛾子数量在1951年至1980年左右可能较为稳定，从那时起到2016年波动并缓慢下降，2017年急剧暴跌。在博贡蛾的主要冬季繁殖地墨累-达令盆地，农业 practices 的变化，如增加作物种植的土地开垦（与欧洲人到来之前相比，每年从山区清除了约2.5亿只蛾子），可能是导致1980年至2016年观察到的博贡蛾数量下降的部分原因。杀虫剂的影响尚不清楚，急需进一步研究。尽管我们几乎没有发现证据表明全球气温上升本身导致了博贡蛾数量下降，但在过去几十年里，澳大利亚的气候变得更加干燥和温暖，这可能阻碍了繁殖地区未成熟阶段的生存，并将成年蛾的夏眠限制在逐渐更高的海拔。2017年蛾子数量的暴跌很可能是由于蛾子繁殖地最近的严重干旱。
