A Monitoring Comparison of Eurasia Otters (lutra Lutra) in Shuangli Wetlands and Yangming Lake Reservoir in Kinmen During 2011-2015

27 Mar A Monitoring Comparison of Eurasia Otters (lutra Lutra) in Shuangli Wetlands and Yangming Lake Reservoir in Kinmen During 2011-2015

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Abstract

歐亞水獺(Lutra lutra)屬於哺乳類食肉目貂科物種。過去在臺灣曾於溪流區域廣泛分布，然而現今僅少數的野外個體活動於金門地區，為瀕臨絕種之保育類動物。族群監測及棲地改善為現今歐亞水獺保育的重要課題。本研究2011年於金門之雙鯉濕地自然中心旁涵洞架設攝影機監測歐亞水獺活動情形，2014年於金門之雙鯉濕地自然中心旁水池及陽明湖水庫增設人工浮島和階梯，營造合適水獺活動之棲地，並架設自動照相機藉以了解歐亞水獺利用該設施的情形。研究結果顯示雙鯉濕地自然中心涵洞具有較高之活動頻率但有下降趨勢(OI值：7.54-12.67)，人工浮島具有較高之停留/休息紀錄(OI值：0.00-5.56)，陽明湖水庫再次記錄歐亞水獺於該區活動(OI值：0.74-2.22)。推測雙鯉濕地自然中心涵洞為連結雙鯉湖及周遭湖泊重要之生物廊道，惟近年來人為活動趨繁及環境劣化可能影響該區歐亞水獺活動。人工浮島及陽明湖水庫人工階梯設置可提供歐亞水獺利用、連結水系，提高歐亞水獺出現頻率。藉由本研究監測系統之建立，未來若搭配族群遺傳研究，將可了解金門地區歐亞水獺族群動態。

English Abstract

In Taiwan, wild populations of Eurasia otter (Lutra lutra; Carnivora, Mustelidae) that once widely distributed in basins are now only found on Kinmen Island. This species is considered endangered due to its few population numbers and small population size, making monitoring and habitat improvement important subjects for its conservation. Since 2011, a camera was set up to monitor activities of Eurasian otter at a culvert near Shuangli Wetlands Nature Center. In 2014, islands and ladders were built in Shuangli Wetlands Nature Center and Yangming Lake Reservoir to construct suitable artificial habitats for the Eurasian otter. An automatic camera trapping was also set up to monitor the otters’ utilization of these artificial habitats. Until 2015, the results revealed that higher level of frequency was detected at the culvert (OI: 7.54-12.67) although in a decreasing trend. Resting behavior was also more frequent on the artificial islands (OI: 0.00-5.56). In Yangming Lake Reservoir, activities of Eurasia otter were re-recorded after setting ladders (OI: 0.74-2.22). The culvert is an important corridor that connected Shuangli wetlands and other lakes. However, the low values of OI at the culvert suggest that human disturbances and environment degradations may have affected the otter. By setting up artificial habitats, occurrences of Eurasia otter increased in frequency, thus indicating improvement of the species’ utilization of culvert and better connection with the river systems. Construction of monitoring system and population genetic analysis should further contribute to the understanding of the population dynamics of Eurasian otter in Kinmen.