1980 年 8 巻 2-3 号 p. 59-69
New visual methods, the identification method and the block count, for counting serows (Capricornis crispus), were tested in Wakinosawa Village, Shimokita Peninsular, Aomori Prefecture from October 1975 to December 1976. Accuracy of the block count was related to seasonal changes of visibility of the study area and by the size of count unit, and was checked by“n-s”curve, representing the relation between number of serows counted and average size of count units; the count units smaller, higher the accuracy. Visibility was affected by plant development, defoliation, and snow accumulation. The highest accuracy was gotten in less than 5 ha unit size in summer and in less than 10 ha unit size after defoliation. In the identification method, both the minimum and maximum numbers of serows were estimated, and the actual number was probably near their median. In Mt. Gange and its vicinity, 225 ha in size, serow density was about 9.8 head per km2in average by the block count, and in the extended area of 500 ha in size, including the above area, it was about 7.0 head per km2in average by the identification method.