关键词: 藏狐, 家域, 利用概率百分比, 最小凸多边形法, 固定核空间法

Abstract: The minimum convex polygon (MCP)and the fixed kernel estimator (FKE)are the two methods most used for
home range estimation. However,because of the problems like spatial data dependence and extreme data points,the usage of these two methods is limited. In this paper,we attempted to analyze and compare the results from these two methods, and discuss how to avoid the disadvantages of each method to make the home range estimation more accurate. We documented 352 locations of 7 adult Tibetan foxes (Vulpes ferrilata) in Shiqu County,Sichuan Province and Dulan County,Qinghai Province during 2006 and 2007. Both MCP and FKE were used to calculate the home range. We found:(1)when the utility probability percentage was set ≤95% ,the difference of the home range size calculated by these two methods had no significant difference;(2)although FKE was more robust than MCP,extreme data points influenced the calculation of both the two methods in higher utilization probability percentage (i. e.,85% - 100% ); (3)home range size calculated by FKE was influenced significantly by the setting of smoothing parameter h which could be determined arbitrarily and the least squares cross validation did not always provide the best evaluation of h. We recommended that both of the FKE and 95% MCP should be used in the same home range study. FKE can be the better home range estimator when the autocorrelation of data spatial distribution is not significant. However,95% MCP can be the only choice especially when the comparison of the results from different telemetry studies is needed.

Key words: Fixed kernel estimation, Home range, Minimum convex polygon, Tibetan fox (Vulpes ferrilata), Utility probability percentage