Movement ecology of an endangered mesopredator in a mining landscape

Abstract Background Efficient movement and energy expenditure are vital for animal survival. Human disturbance can alter animal movement due to changes in resource availability and threats. Some animals can exploit anthropogenic disturbances for more efficient movement, while others face restricted or inefficient movement due to fragmentation of high-resource habitats, and risks associated with disturbed habitats. Mining, a major anthropogenic disturbance, removes natural habitats, introduces new landscape features, and alters resource distribution in the landscape. This study investigates the effect of mining on the movement of an endangered mesopredator, the northern quoll (Dasyurus hallucatus). Using GPS collars and accelerometers, we investigate their habitat selection and energy expenditure in an active mining landscape, to determine the effects of this disturbance on northern quolls. Methods We fit northern quolls with GPS collars and accelerometers during breeding and non-breeding season at an active mine site in the Pilbara region of Western Australia. We investigated broad-scale movement by calculating the movement ranges of quolls using utilisation distributions at the 95% isopleth, and compared habitat types and environmental characteristics within observed movement ranges to the available landscape. We investigated fine-scale movement by quolls with integrated step selection functions, assessing the relative selection strength for each habitat covariate. Finally, we used piecewise structural equation modelling to analyse the influence of each habitat covariate on northern quoll energy expenditure. Results At the broad scale, northern quolls predominantly used rugged, rocky habitats, and used mining habitats in proportion to their availability. However, at the fine scale, habitat use varied between breeding and non-breeding seasons. During the breeding season, quolls notably avoided mining habitats, whereas in the non-breeding season, they frequented mining habitats equally to rocky and riparian habitats, albeit at a higher energetic cost. Conclusion Mining impacts northern quolls by fragmenting favoured rocky habitats, increasing energy expenditure, and potentially impacting breeding dispersal. While mining habitats might offer limited resource opportunities in the non-breeding season, conservation efforts during active mining, including the creation of movement corridors and progressive habitat restoration would likely be useful. However, prioritising the preservation of natural rocky and riparian habitats in mining landscapes is vital for northern quoll conservation.

摘要：
【研究背景】高效移动与能量消耗对动物生存至关重要。人类活动干扰会通过改变资源可获得性与威胁因素，进而改变动物的移动模式。部分动物可借助人为干扰实现更高效的移动，而另一些动物则因高资源栖息地破碎化、受干扰栖息地伴随的风险，面临移动受限或移动效率低下的问题。采矿作为主要的人为干扰源，会移除自然栖息地、引入全新的景观要素，并改变区域内的资源分布格局。本研究以濒危中型捕食者北袋鼬（Dasyurus hallucatus）为研究对象，探讨采矿活动对其移动行为的影响。本研究借助GPS项圈与加速计，对西澳大利亚皮尔巴拉地区一处正在运营的矿区内北袋鼬的栖息地选择与能量消耗展开研究，以明确该干扰活动对北袋鼬的作用效果。
【研究方法】本研究于西澳大利亚皮尔巴拉地区的一处活跃矿区，在繁殖季与非繁殖季为北袋鼬佩戴GPS项圈与加速计。我们通过95%等高线利用分布计算北袋鼬的移动范围，以此分析其宏观尺度移动模式，并将观测到的移动范围内的栖息地类型与环境特征，与区域内可利用景观进行对比。我们采用集成步选择函数分析北袋鼬的微观尺度移动行为，评估各栖息地协变量的相对选择强度。最后，本研究运用分段结构方程模型分析各栖息地协变量对北袋鼬能量消耗的影响。
【研究结果】宏观尺度上，北袋鼬主要利用崎岖多岩的栖息地，对采矿栖息地的利用比例与其可获得性相当。但在微观尺度上，其栖息地选择在繁殖季与非繁殖季存在显著差异：繁殖季北袋鼬会显著避开采矿栖息地；而非繁殖季，它们对采矿栖息地的利用频次与岩地、河岸栖息地相当，尽管这会带来更高的能量消耗成本。
【研究结论】采矿活动通过破碎化北袋鼬偏好的岩地栖息地、提升其能量消耗，以及潜在影响繁殖扩散行为，对北袋鼬造成负面影响。尽管非繁殖季采矿栖息地或许能提供有限的资源获取机会，但在采矿运营期间开展保护工作——包括构建移动廊道与逐步推进栖息地修复——或将起到积极作用。然而，优先保护矿区内的自然岩地与河岸栖息地，对北袋鼬的物种保护至关重要。