利用红外相机监测数据分析佛坪国家级自然保护区豹猫和黄喉貂活动节律及空间分布

豹猫(Prionailurus bengalensis)和黄喉貂(Martes flavigula)均为国家Ⅱ级重点保护野生动物,常同域分布,但是其生态位差异和共存机制尚不明确。为了探究这一问题,从2013年9月至2018年12月,在陕西省佛坪国家级自然保护区内共计布设37台触发式红外相机。37台相机均持续工作5年,用于对这两种中小型食肉动物的聚群模式、日活动节律、季节性动态和空间分布进行系统监测,累计相机工作日72076d,共捕获到独立有效事件豹猫290次、黄喉貂84次。结果表明,豹猫是典型的独居型物种,偏好夜行性,其夜间活动指数D_RAI为77.4%;而黄喉貂更倾向于聚群活动,是昼行性生物,其昼间活动指数DRAr为94.1%。豹猫的季节相对多度指数SRAI,冷季显著高于暖季(1=2.82,df=11,P<0.05);而黄喉貂的季节相对多度指数暖季显著高于冷季(t=-3.09,df=11,P<0.05),两种动物的月相对多度指数MRAI都呈现出明显的季节性波动规律。豹猫和黄喉貂在空间分布上存在明显的相互回避,在距离人类活动的道路较近的区域,即距离道路小于500 m范围内,豹猫的活动比黄喉貂更加频繁,其相机位点多度指数CRAI显著高于黄喉貂(Wilcoxon秩和检验P<0.001)。本研究结果显示,这两种小型:食肉动物可以通过占据不同的时空生态位来减少竞争,从而达到大范围区域共存。

Using Infrared Camera Traps to Monitor the Activity Rhythm and Spatial Distribution Pattern of Leopard Cat (Prionailurus bengalensis) and Yellow- throated Marten (Martes flavigula) in Foping National Nature Reserve

Objectives]The Leopard Cat(Prionailurus bengalensis)and Yellow-throated Marten(Martes flavigula)are both the national second-class protected species.However,as sypatric species,their ecological niche and coexistence mechanism are nevertheless unclear.Methods]From September 2013 to December 2018,37 infrared camera traps were set up in the Foping National Nature Reserve in Shaanxi Province.Our study area and camera trap sites can be seen from Fig.1.Based on the monitoring data,we calculated the relative abundance index to model the cluster pattern,daytime-and-night activity rhythm,seasonal dynamics and spatial distribution of these two small and medium sized carnivores.Seasonal activity rhythm were tested by t-test and spatial activity pattern were tested by Wilcoxon rank sum test.Daily activity rhythm was modeled by kernel density method and inverse distance weighted method(weight=5)was used to draw spatial activity pattern.All the analysis were conducted in R 3.6.3.Results]There were a total of 72076 camera working days and captured 290 independent and effective incidents of Leopard Cats and 84 independent and effective incidents of Yellow-throated Martens.The results showed that the Leopard Cat is a typical solitary species,preferring activity in the night(daytime-and-night relative abundance index,D_RAI=77.4%).While the Yellow-throated Marten is more gregarious and more activity in the day time(Drai=94.1%)(Fig.2a).Leopard Cats reach their activity peak in a day between 3:00 and 4:00 am and the activity peak of Yellow-throated Martens appeared at 17:00(Fig.2a).The relative seasonal abundance index Sraj of Leopard Cats is significantly higher in the cold season than in the warm season(t=2.82,df=11,P<0.05),while the Srm of Yellow-throated Marten is significantly higher in the warm season than in the cold season(t=-3.09,df=11,P<0.05)(Fig.3 a).The monthly relative abundance index Mrai of the two species showed obvious seasonal fluctuations(Fig.3b).There was significant mutual avoidance between Leopard Cats and Yellow-throated Martens in spatial distribution.However,Leopard Cats is more frequently recorded in the area active moved more frequently in areas closer to human paths than Yellow-throated Martens(Fig.4a).The camera site abundance of index Crm to the road within 500 m is significantly higher for Leopard cat’s than that of Yellow-throated Marten(Distance,Wilcoxon rank sum test:P<0.001)(Fig.4b).Conclusion]The two small carnivorous mammals occupied different spatial and temporal ecological niches to reduce competition and achieve coexistence in a large region.