河南内乡宝天曼国家级自然保护区豹猫及其潜在猎物之间日活动节律的季节性

日活动节律是动物应对食物可利用性、天敌捕食风险和环境条件等变化的适应性特征。阐明捕食者与猎物之间的日活动节律以及相关影响因素, 对于理解不同物种的生存策略、指导保护对策至关重要。然而, 由于采样方法的限制和人类干扰下的快速环境变化, 人们对许多野生动物日活动节律的了解并不全面, 甚至与实际情况存在偏差。以往认为夜行性的豹猫(Prionailurus bengalensis)被发现有一定程度的日间活动, 并增加晨昏活动, 这说明有必要深入调查豹猫等野生动物的昼夜节律为何存在这些变化。本研究在河南内乡宝天曼国家级自然保护区通过红外相机技术对豹猫及其潜在猎物进行调查, 基于核密度函数比较分析了豹猫与其潜在猎物在冷、暖季节的日活动节律。2016年全年设置了55个红外相机位点, 累计14,972个相机工作日, 获得豹猫及其潜在猎物的独立有效照片1,343张。结果显示, 该保护区内豹猫、蒙古兔(Lepus tolai)和鼠类以夜间活动为主, 其中豹猫有明显的晨昏活动高峰, 而赤腹松鼠(Callosciurus erythraeus)、岩松鼠(Sciurotamias davidianus)、红腹锦鸡(Chrysolophus pictus)和勺鸡(Pucrasia macrolopha)均在昼间活动。活动重叠度分析结果显示, 豹猫与夜行性的蒙古兔和鼠类在冷季和暖季均有较高重叠度(Δ ≥ 0.50), 但与其他猎物之间的重叠度均相对较低(Δ ≤ 0.40)。本研究显示豹猫及其猎物的昼夜节律既有保守性, 也具有一定的季节可塑性, 可能受到季节性猎物分布和环境变化的影响。因此, 需要加强调查研究来充分认识不同物种日活动节律的季节性变化规律及其驱动因素。

Seasonal variation of daily activity rhythm of leopard cats (Prionailurus bengalensis) and their potential prey in Neixiang Baotianman National Nature Reserve of Henan Province,China

Aim: The daily activity rhythm of wild animals is an adaptive response to food availability, predation risk, and environmental constraints. Therefore, elucidating the driving factors of daily activity rhythms are crucial in understanding wildlife fitness and conservation. Knowledge about the daily activity rhythms of most wild animals is rudimentary and occasionally inaccurate due to limited sampling and anthropogenic environmental changes. Leopard cats (Prionailurus bengalensis)—formerly believed to be nocturnal—are found to have some diurnal activity, along with their primary crepuscular activity. This illustrates the necessity of investigating how daily activity rhythm in wild animals, such as leopard cats, changes over time and space. Methods: During 2016, we deployed 55 infrared-triggered cameras to monitor leopard cats and their potential prey in the Neixiang Baotianman National Nature Reserve, Henan Province. We compared daily activity patterns by employing a kernel density estimation and using overlap coefficient to quantify the temporal overlap between leopards cat and their potential prey across warm and cold seasons. Results: We identified 1,343 independent images of leopard cats and their potential prey over 14,972 camera trapping days. We found leopard cats, Tolai hares (Lepus tolai), and nocturnal rats mainly active at night, with the leopard cat’s activity peaking at dusk and dawn. Conversely, Pallas’s squirrels (Callosciurus erythraeus), Pere David’s rock squirrels (Sciurotamias davidianus), golden pheasants (Chrysolophus pictus) and koklass pheasants (Pucrasia macrolopha) were all diurnal. More diurnal activity of leopard cats and their potential prey (except nocturnal rats) occurred during warm seasons. Overlap analysis showed that leopard cats had a higher overlap coefficient with Tolai hares and nocturnal rats across warm and cold seasons (Δ ≥ 0.50) than with any diurnal prey (Δ ≤ 0.40). Conclusions: Our study demonstrates that daily activity rhythm for leopard cats and their potential prey may be relatively conserved, but with some seasonal plasticity. This plasticity may be caused by seasonal variation in environment and prey distribution. Our results indicate that broad-scale monitoring and research are essential to elucidate the causes and seasonal variations in daily activity rhythms of wild animals.