There is increasing evidence that occasional utilization area (peripheral sites), in addition to typical utilization area (home range), is important for wildlife conservation and management. Here we estimated the maximum utilization area (MUA), including both typical and occasional utilization areas, based on asymptotic curves of utilization area plotted against sample size. In previous studies, these curves have conventionally been plots of cumulative utilization area versus sample size, but this cumulative method is sensitive to stochastic effects. We propose a new method based on simulation studies where outcomes of replicated simulations are averaged to reduce stochastic effects. In this averaged method, possible combinations of sample size with the same number of location data replicated from a dataset were averaged and applied to the curves of utilization area. The cumulative method resulted in a large variation of MUA estimates, depending on the start date as well as total sample size of the dataset. In the averaged method, MUA estimates were robust against changes in the start date and total sample size. The large variation of MUA estimates arose because location data on any day including the start date are affected by unpredictable effects associated with animal activity and environmental conditions. In the averaged method, replicates of sample size resulted in a reduction of temporal stochasticity, suggesting that the method stably provides reliable estimates for MUA.

野崎 健太郎 1) ＊ ・井上 光也 2) ・寺山 佳奈 2) ・高橋 伸行 3) ・加藤 元海 4) 1)椙山女学園大学教育学部 〒464 8662 名古屋市千種区星が丘元町 17 3 2)高知大学大学院総合人間自然科学研究科 〒780 8520 高知県高知市曙町 2 5 1 3)愛知県立松蔭高等学校 〒453 0855 名古屋市中村区烏森町 2 2 4)高知大学理学部 〒780 8520 高知県高知市曙町 2 5 1 Kentaro NOZAKI 1) *, Mitsuya INOUE 2) , Kana TERAYAMA 2) , Nobuyuki TAKAHASHI 3) and Motomi GENKAI-KATO 4) : A learning program of residential outdoor environmental education for university students to understand the stream ecosystem diversity. Ecol. Civil Eng. 20 (1) , 99-105,