Juillard Loic Q, Ashby Lisa M, McEvoy Taylor J, Ramp Daniel
Centre for Compassionate Conservation, TD School, University of Technology Sydney, Ultimo 2007 NSW, Australia.
Centre for Compassionate Conservation, TD School, University of Technology Sydney, Ultimo 2007 NSW, Australia.
J Therm Biol. 2025 Aug;132:104245. doi: 10.1016/j.jtherbio.2025.104245. Epub 2025 Aug 20.
In semi-arid drylands, landscape features such as water and trees are vital for individuals when reducing heat stress. In Australia, such landscapes have witnessed widespread canopy loss and considerable shifts in water availability due to anthropogenic processes, and are subject to greater frequencies of extreme temperatures. We explored the use of dammed watercourses and excavated earth tanks, and tree shade in two large macropod species, eastern grey kangaroos (Macropus giganteus) and red kangaroos (Osphranter rufus) in the semi-arid drylands of south-western Queensland. Using a thermal drone, camera traps, and temperature sensors, we examined the relationship between temperature, and water and canopy shade use by both species. The likelihood of kangaroos being observed in the sun was negatively correlated with temperature, with the likelihood of observing eastern grey kangaroos in the sun dropping below 50 % when temperatures exceeded 28 °C, and 17 °C for red kangaroos. Probability of detecting kangaroos in the shade was positively correlated with temperature, with red kangaroos more strongly selecting shade than eastern grey kangaroos. For eastern grey kangaroos, we observed greatly increased activity at waterpoints when daily maximum temperatures exceeded 28 °C, with a preference for dammed watercourses over excavated earth tanks. Only a weak trend of using dammed watercourses at high temperatures (>36 °C) was detected for red kangaroos. As higher temperatures become more frequent due to climate change, our results suggest that the capacity of wildlife to persist may increasingly depend on the provision and maintenance of landscape features such as water and canopy shade.
在半干旱旱地，水和树木等景观特征对于个体减轻热应激至关重要。在澳大利亚，由于人为活动，这些景观出现了大面积的树冠损失以及水资源可利用性的显著变化，并且极端温度出现的频率更高。我们在昆士兰州西南部的半干旱旱地，对东部灰袋鼠（Macropus giganteus）和红袋鼠（Osphranter rufus）这两种大型有袋类动物，研究了筑坝水道、挖掘土池以及树荫的利用情况。我们使用热成像无人机、相机陷阱和温度传感器，研究了这两个物种的温度、水和树冠遮蔽利用之间的关系。袋鼠在阳光下被观察到的可能性与温度呈负相关，当温度超过28°C时，东部灰袋鼠在阳光下被观察到的可能性降至50%以下，红袋鼠则为17°C。在树荫下检测到袋鼠的概率与温度呈正相关，红袋鼠比东部灰袋鼠更强烈地选择树荫。对于东部灰袋鼠，当每日最高温度超过28°C时，我们观察到它们在饮水点的活动大幅增加，并且它们更喜欢筑坝水道而非挖掘土池。对于红袋鼠，仅在高温（>36°C）时有使用筑坝水道的微弱趋势。由于气候变化导致更高温度愈发频繁，我们的研究结果表明，野生动物持续生存的能力可能越来越依赖于水和树冠遮蔽等景观特征的提供与维护。
