Wang Dong, Li Quanbang, Gao Jingyu, Su Xu, Lian Xinming
School of Geographical Science, Qinghai Normal University, Xining 810016, China.
Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.
Animals (Basel). 2025 Jul 12;15(14):2059. doi: 10.3390/ani15142059.
Activity patterns constitute a critical adaptive trait in large carnivores, enabling them to manage interspecific competition, enhance their foraging efficiency, and adapt to fluctuating environmental conditions. At the community level, elucidating the temporal activity allocation of sympatric large carnivores is essential for understanding species coexistence mechanisms. However, the activity patterns of most large carnivores remain inadequately explored. In this study, spanning a survey period from June 2014 to April 2024, we employed infrared camera technology to collect a total of 3312, 352, 240, and 79 independently validated photographs of snow leopards ( Schreber, 1775), wolves ( Linnaeus, 1758), brown bears ( Linnaeus, 1758), and Eurasian lynx ( Linnaeus, 1758), respectively, across six distinct regions in the Sanjiangyuan Region (SR) and during different monitoring time periods. We utilized kernel density estimation and the coefficient of overlaps to assess diel activity pattern overlap and competitive intensities through pairwise comparisons among these four large carnivores. An analysis of the diel activity rhythm curves revealed that all four large carnivores predominantly exhibited nocturnal behavior, although their peak activity periods differed notably. Furthermore, the diel activity rhythm overlap between each pair of species showed moderate to high intensity throughout the year (0.5 ≤ Δ < 1), including during both the cold and warm seasons. Specifically, the diel activity rhythms of snow leopards and wolves, snow leopards and Eurasian lynx, and wolves and Eurasian lynx exhibited high levels of overlap annually and during the cold season (0.8 ≤ Δ < 1) but only moderate overlap during the warm season (0.5 ≤ Δ < 0.8). Our findings suggest that the diel activity rhythms of these four large carnivore species exhibited considerable overlap, potentially intensifying interspecific competition. This study advances our knowledge on the competitive and coexistence mechanisms of large carnivores in high-altitude mountainous ecosystems, offering critical data for their conservation and management.
活动模式是大型食肉动物的一种关键适应性特征，使它们能够应对种间竞争、提高觅食效率，并适应不断变化的环境条件。在群落层面，阐明同域大型食肉动物的时间活动分配对于理解物种共存机制至关重要。然而，大多数大型食肉动物的活动模式仍未得到充分研究。在这项研究中，调查期从2014年6月至2024年4月，我们运用红外相机技术，在三江源地区（SR）的六个不同区域以及不同监测时间段，分别独立获取了3312张、352张、240张和79张雪豹（Schreber，1775）、狼（Linnaeus，1758）、棕熊（Linnaeus，1758）和欧亚猞猁（Linnaeus，1758）的有效照片。我们利用核密度估计和重叠系数，通过对这四种大型食肉动物进行两两比较，来评估昼夜活动模式的重叠情况和竞争强度。对昼夜活动节律曲线的分析表明，尽管这四种大型食肉动物的活动高峰期明显不同，但它们都主要表现出夜行性。此外，每对物种之间的昼夜活动节律全年都呈现出中度到高强度的重叠（0.5≤Δ<1），包括寒冷和温暖季节。具体而言，雪豹和狼、雪豹和欧亚猞猁以及狼和欧亚猞猁的昼夜活动节律在每年和寒冷季节都表现出高度重叠（0.8≤Δ<1），但在温暖季节仅为中度重叠（0.5≤Δ<0.8）。我们的研究结果表明，这四种大型食肉动物物种的昼夜活动节律存在相当大的重叠，可能会加剧种间竞争。这项研究增进了我们对高海拔山区生态系统中大型食肉动物竞争和共存机制的认识，为它们的保护和管理提供了关键数据。
