Australian mammals have exhibited exceptionally high rates of decline since European settlement 230 years ago with much focus on small mammals in northern tropical savannas. In these systems, little scientific attention has been given to the suite of grazing macropods, family Macropodidae, (common wallaroo (Osphranter robustus), antilopine wallaroo (O. antilopinus) and agile wallaby (Notamacropus agilis)). These species may be impacted by feral herbivores and contemporary fire regimes, two threats linked to small mammal declines. A multi‐scale approach using aerial surveys, road surveys and camera trapping was utilised to determine the effects of feral cattle and fire on the distribution and abundance of large macropods in the North Kimberley bioregion. Feral cattle density and biomass exceeded that of macropods regardless of survey technique. Density estimates for cattle were up to 125 times higher (0.3–10.0 km-2) than estimates for macropods (0.08–0.49 km-2). Cattle biomass, based on the aerial survey estimates (corrected for perception bias), were 15 and 95 times higher than macropods for infertile (279 vs. 19 kg km-2) and fertile savannas (518 vs. 5 kg km-2), respectively. Proximity to the nearest pastoral station was a significant predictor of the aerial sightings of feral cattle (P ≤ 0.05). Abundance and foraging activity of cattle were positively associated (P ≤ 0.05) with recently burnt areas. In contrast, camera trapping showed agile wallaby and wallaroo occurrence and foraging were associated with longer unburnt areas (P ≤ 0.05). Agile wallaby and wallaroo were negatively associated with cattle (P ≤ 0.05) and showed substantial diurnal and seasonal separation consistent with an antagonistic interspecific interaction. Results also suggest that the agile wallaby is the primary prey of the dingo, not wallaroo. Collectively, this study suggests that recent landscape changes such as altered fire regimes and introduced herbivores have negatively impacted large grazing macropod species.

中文翻译：

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澳大利亚北部热带稀树草原中大型食草动物的分布和丰度：多尺度方法

自 230 年前欧洲人定居以来，澳大利亚哺乳动物的数量下降速度非常快，主要集中在北部热带稀树草原的小型哺乳动物。在这些系统中，对放牧巨足动物、巨足科（Macropodidae）（普通袋鼠（Osphranterrobustus）、antilopine 袋鼠（O. antilopinus）和敏捷袋鼠（Notamacropus agilis））的科学关注很少。这些物种可能会受到野生食草动物和当代火灾制度的影响，这两种威胁与小型哺乳动物的数量减少有关。使用航空调查、道路调查和相机捕获的多尺度方法来确定野牛和火灾对北金伯利生物区大型巨足类的分布和丰度的影响。无论调查技术如何，野牛的密度和生物量都超过了巨足类动物。牛的密度估计值（0.3-10.0 km-2）比巨足类的估计值（0.08-0.49 km-2）高 125 倍。根据航空调查估计（根据感知偏差进行校正），牛的生物量是不育（279 对 19 kg km-2）和肥沃稀树草原（518 对 5 kg km-2）的巨足类动物的 15 倍和 95 倍，分别。靠近最近的牧区是野牛空中目击的重要预测因素（P ≤ 0.05）。牛的丰富度和觅食活动与最近被烧毁的区域呈正相关（P ≤ 0.05）。相比之下，相机诱捕显示敏捷小袋鼠和小袋鼠的出现和觅食与较长的未燃烧区域有关（P ≤ 0.05）。敏捷小袋鼠和小袋鼠与牛呈负相关（P ≤ 0. 05) 并显示出大量的昼夜和季节性分离，与拮抗的种间相互作用一致。结果还表明，敏捷的小袋鼠是野狗的主要猎物，而不是袋鼠。总的来说，这项研究表明，最近的景观变化，例如改变的火势和引入的食草动物，对大型食草巨足类物种产生了负面影响。