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

Abstract

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.