使用粪堆数量估计日本奄美群岛上琉球兔的种群数量

为了测量奄美岛上濒危物种琉球兔 (Pentalagusfurnessi)的丰盛度 ,我们计数了森林中道路、溪流和森林地被物中的粪堆数量。计算用的模型包括新粪堆的数量及其年龄、总粪堆数量、每天产生的平均粪堆数 ,以及在森林地被物和溪边的粪堆数量的回归方程。估计在 1 993- 1 994年期间该岛上有 2 5 0 0 - 6 1 0 0只琉球兔 ,在 2 0 0 2 - 2 0 0 3年间有 2 0 0 0 - 4 80 0只。通过比较粪便丰盛度和在森林道路旁观察到的琉球兔数量 ,我们考察了该模型的有效性 ,最后将以前调查的数据应用于该模型以确定种群下降的程度

Estimating population size of the Amami rabbit Pentalagus furnessi based on fecal pellet counts on Amami Island, Japan

To measure the abundance of the endangered Amami rabbit on Amami Island,we counted their fecal pellets on forest roads, streams and forest floors. The estimation model comprised the number of new pellets, their age, the total number of pellets, average number of pellets produced in a day and a regression equation between the number of pellets on a forest floor and streamside. We estimated the total number of rabbits to be 2 500 - 6 100 in 1993-1994 and 2 000 - 4 800 in 2002-2003. We examined the validity of the model by comparing the fecal abundance and the number of rabbits observed along forest roads. Finally we applied previous survey data to the model in order to estimate the degree of population decline.