McLean Dusty, Goldingay Ross, Letnic Mike
Faculty of Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia.
Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
Animals (Basel). 2023 Jul 10;13(14):2257. doi: 10.3390/ani13142257.
Carnivores fulfil important ecological roles in natural systems yet can also jeopardise the persistence of threatened species. Understanding their diet is, therefore, essential for managing populations of carnivores, as well as those of their prey. This study was designed to better understand the diet of an Australian apex predator, the dingo, and determine whether it poses a threat to at-risk small macropods in two floristically different yet geographically close reserves in subtropical Australia. Based on an analysis of 512 scats, dingo diets comprised 34 different prey taxa, of which 50% were common between reserves. Our findings add support to the paradigm that dingoes are opportunistic and generalist predators that prey primarily on abundant mammalian fauna. Their diets in the Border Ranges were dominated by possum species (frequency of occurrence (FOC) = 92.5%), while their diets in Richmond Range were characterised by a high prevalence of pademelon species (FOC = 46.9%). Medium-sized mammals were the most important dietary items in both reserves and across all seasons. The dietary frequency of medium-sized mammals was generally related to their availability (indexed by camera trapping); however, the avoidance of some species with high availability indicates that prey accessibility may also be important in dictating their dietary choices. Other prey categories were supplementary to diets and varied in importance according to seasonal changes in their availability. The diets included two threatened macropods, the red-legged pademelon and black-striped wallaby. Our availability estimates, together with earlier dietary studies spanning 30 years, suggest that the red-legged pademelon is resilient to the observed predation. The black-striped wallaby occurred in only two dingo scats collected from Richmond Range and was not detected by cameras so the threat to this species could not be determined. Two locally abundant but highly threatened species (the koala and long-nosed potoroo) were not detected in the dingoes' diets, suggesting dingoes do not at present pose a threat to these populations. Our study highlights the importance of site-based assessments, population monitoring and including data on prey availability in dietary investigations.
食肉动物在自然系统中扮演着重要的生态角色，但也可能危及濒危物种的生存。因此，了解它们的饮食对于管理食肉动物及其猎物的种群至关重要。本研究旨在更好地了解澳大利亚顶级食肉动物——澳洲野犬的饮食，并确定其是否对澳大利亚亚热带地区两个植物区系不同但地理位置相近的保护区中面临风险的小型有袋类动物构成威胁。基于对512份粪便的分析，澳洲野犬的饮食包括34种不同的猎物分类单元，其中50%在两个保护区中是相同的。我们的研究结果支持了这样一种范式，即澳洲野犬是机会主义和广食性的食肉动物，主要捕食丰富的哺乳动物。它们在边境山脉的饮食以负鼠种类为主（出现频率（FOC）=92.5%），而在里士满山脉的饮食则以赤褐袋鼠种类的高占比为特征（FOC = 46.9%）。中型哺乳动物是两个保护区以及所有季节中最重要的食物种类。中型哺乳动物的饮食频率通常与其可获得性（通过相机捕捉来衡量）相关；然而，对一些可获得性高的物种的回避表明，猎物的易获取性在决定它们的饮食选择方面可能也很重要。其他猎物类别是饮食的补充，其重要性根据其可获得性的季节性变化而有所不同。饮食中包括两种濒危有袋类动物，赤褐袋鼠和黑纹小袋鼠。我们的可获得性估计，以及跨越30年的早期饮食研究表明，赤褐袋鼠对观察到的捕食具有恢复力。黑纹小袋鼠仅出现在从里士满山脉收集的两份澳洲野犬粪便中，且未被相机检测到，因此无法确定对该物种的威胁。在澳洲野犬的饮食中未检测到两种当地数量丰富但受到高度威胁的物种（考拉和长鼻袋狸），这表明澳洲野犬目前对这些种群不构成威胁。我们的研究强调了基于地点的评估、种群监测以及在饮食调查中纳入猎物可获得性数据的重要性。
