黄腹角雉(Tragopan caboti)巢捕食模拟实验

Simulation Experiment of Cabot's Tragopan( Tragopan caboti) Nest Predation

为了解江西武夷山黄腹角雉(Tragopan caboti)种群孵卵期巢捕食状况。在海拔1270～1345 m和海拔1805～1920 m的黄腹角雉栖息地,设立实验地A和实验地B,分别在实验地离地高1. 8～5. 4 m的树杈上安装人工巢20个,巢间距离50～80 m,人工巢经过110 d的环境适应;于2015年黄腹角雉繁殖季节,在每巢安放2枚模拟卵(鸡蛋),每巢安装1台红外照相机进行监测。经过28 d的模拟实验,实验地A被捕食12巢,被捕食率60. 0%,捕食者均为藏酋猴(Macaca thibetana);实验地B被捕食5巢,被捕食率25. 0%,捕食者均为松鸦(Garrulus glandarius);模拟卵是否被捕食,与人工巢的离地高度、模拟卵是否进行了覆盖处理,没有直接联系。藏酋猴在黄腹角雉孵卵期,局限于较低海拔的实验地A区域活动,可能与食物资源的季节性差异有关。松鸦捕食行为仅发生于实验地B,松鸦仅捕食人工巢(2枚模拟卵)、黄腹角雉自然巢(3枚卵)中的1枚卵,松鸦如何能识别出真假鸟卵或其选择性捕食机理有待进一步研究。

We studied nest predation on Cabot s tragopan(Tragopan caboti)during the incubating period in the Wuyi Mountains of Jiangxi Province.Our experimental site A was set at elevation 1270-1345 m and experimental site B was at elevation 1805-1920 m.Twenty man-made nests were set up at each experimental plot 110 days before incubating period to blend into the natural environment.The nests were set 1.8 m to 5.4 m above the ground in trees,and 50-80 m from one another.We placed two eggs in each nest during breeding season 2015 and one infrared camera was placed beside each nest to identify predators.After 28 days of simulation,twelve nests(60.0%)were depredated at site A,all by Tibetan macaque(Macaca thibetana).Five nests(25%)were depredated at site B,all by Eurasian jay(Garrulus glandarius).Nest predation was not directly related to the height of man-made nest or whether eggs were covered.During the incubation period of cabot s tragopan,activity of Tibetan macaque was limited at plot A,possibly due to seasonal differences in food availability.Predation of eurasian jay only occurred at plot B.Further research is needed to understand why eurasian jay preyed only on eggs in artificial nests and ate from only one of three eggs in a natural Cabot s tragopan nest which it had found.