Lane Murraya R, Youngentob Kara N, Clark Robert G, Skewes James D, Marsh Karen J
Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.
Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.
Mov Ecol. 2024 Dec 3;12(1):75. doi: 10.1186/s40462-024-00519-0.
Wildfires can have complex effects on wildlife populations. Understanding how post-fire conditions affect the movement ecology of threatened species can assist in better conservation and management, including informing the release of rescued and rehabilitated animals. The 2019-2020 megafires in Australia resulted in thousands of animals coming into care due to injury or concerns over habitat degradation. This included hundreds of koalas (Phascolarctos cinereus), for which relatively little was known about how fire affected habitat suitability, or when rehabilitated animals could be returned to burnt areas.
We compared the movements of koalas across three experimental groups-non-rehabilitated koalas in burnt habitat, non-rehabilitated koalas in nearby unburnt habitat, and rehabilitated koalas returned to their rescue location in burnt habitat in New South Wales, Australia. We GPS-tracked 32 koalas for up to nine months and compared, across treatment groups, home ranges, mean nightly distance moved, the farthest distance moved from their release site and total displacement distance.
We found no differences in koala movements and home range size between non-rehabilitated koalas in burnt and unburnt habitat. However, rehabilitated koalas moved farther from their release site, had larger displacement distances, and larger home ranges than non-rehabilitated individuals. Regardless of their experimental group, we also found that males moved further than females each night. Additionally, our resource selection analysis showed that, koalas preferred low and moderately burnt habitats over all other fire severity classes.
Experimental frameworks that incorporate "treatment" and "control" groups can help isolate disturbance effects on animal movements. Encouragingly, despite catastrophic wildfires, burnt woodlands provided adequate resources for koalas to persist and recover. Furthermore, rehabilitated koalas re-integrated into the burnt landscape despite moving farther from their release sites than non-rehabilitated individuals. Studies like this improve our understanding of the ecological impacts of fire on species and their habitats, and will be instrumental in informing wildlife management and conservation efforts as wildfires increase in frequency and severity worldwide in response to climate change.
野火会对野生动物种群产生复杂影响。了解火灾后的条件如何影响濒危物种的运动生态学，有助于更好地进行保护和管理，包括为救助和康复后的动物放归提供信息。2019 - 2020年澳大利亚的特大火灾导致数千只动物因受伤或栖息地退化问题而受到照料。这其中包括数百只考拉（树袋熊），当时对于火灾如何影响栖息地适宜性，以及康复后的动物何时能够返回烧毁区域，人们所知甚少。
我们比较了三组实验考拉的活动情况——在烧毁栖息地的未康复考拉、在附近未烧毁栖息地的未康复考拉，以及被放归到澳大利亚新南威尔士州烧毁栖息地中其获救地点的康复考拉。我们用GPS跟踪了32只考拉长达九个月，并比较了各处理组之间的家域、平均每晚移动距离、从放归地点移动的最远距离以及总位移距离。
我们发现，在烧毁和未烧毁栖息地的未康复考拉之间，考拉的活动和家域大小没有差异。然而，与未康复的个体相比，康复后的考拉从放归地点移动得更远，位移距离更大，家域也更大。无论所属实验组如何，我们还发现雄性考拉每晚移动的距离都比雌性更远。此外，我们的资源选择分析表明，考拉在所有其他火灾严重程度等级中，更喜欢低度和中度烧毁的栖息地。
纳入“处理”和“对照”组的实验框架有助于分离干扰对动物活动的影响。令人鼓舞的是，尽管发生了灾难性的野火，但烧毁的林地为考拉提供了足够的资源以维持生存和恢复。此外，尽管康复后的考拉比未康复的个体从放归地点移动得更远，但它们仍重新融入了烧毁的景观中。这样的研究增进了我们对火灾对物种及其栖息地的生态影响的理解，并且随着全球范围内野火因气候变化而频率和严重程度增加，将有助于为野生动物管理和保护工作提供指导。
