臺灣地區斑腿樹蛙族群分布探討

Distribution of Polypedates megacephalus Hallowell, 1861 (Rhacophoridae, Anura, Amphibia) in Taiwan

斑腿樹蛙為2006年於臺灣中部發現的新紀錄種，外型特徵與臺灣原生種布氏樹蛙相似。本研究於2012年藉由兩棲類保育志工普查、一般民眾通報與方格系統調查，以了解斑腿樹蛙在臺灣的分布現況。使用2006－2012年斑腿樹蛙的分布點與1982－1990年布氏樹蛙歷史調查資料進行方格疊合比較，以探討早期被誤認為布氏樹蛙的斑腿樹蛙為原生種之可能性。結果顯示斑腿樹蛙分布於臺北市、新北市、桃園縣、臺中市、彰化縣、雲林縣與屏東縣，在其分布地區具有族群量高、分布廣泛的特性，且多為當地的優勢物種。在布氏樹蛙歷史分布的363個方格中，無任何方格與斑腿樹蛙分布的方格重疊，而在斑腿樹蛙分布的87個方格中，有40.2%是1982－1990年曾有調查，但未發現布氏樹蛙，顯示斑腿樹蛙有非常高的可能性是外來種。斑腿樹蛙具有高適應力與繁殖力，從發現之後至今仍持續擴散，未來除了在已確認的分布區進行控制外，藉由志工或一般民眾協助進行通報與監測也很重要，以便能及早進行相關保育措施，降低控制成本。

Polypedates megacephalus Hallowell (the spot-legged tree frog, 1861) was found in Central Taiwan in 2006. Its morphology is similar to the native species P. braueri (Vogt, 1911). In this study, P. megacephalus' distribution in Taiwan was investigated by referencing amphibian conservation volunteers' survey data, public reports and grid system surveys. We also compared P. megacephalus' location (survey in 2006-2012) with P. braueri's historical distribution records (survey in 1982-1990) to examine the probability of P. megacephalus being a native species, as it was mistakenly identified as P. braueri previously. The results show that P. megacephalus distributed in Taipei City, New Taipei City, Taoyuan County, Taichung City, Changhua County, Yunlin County and Kaoshiung City. There was no overlap among the 363 P. braueri 's historical grids and 87 P. megacephalus' distribution grids. And in the 87 P. megacephalus' distribution grids, 40.2% grids were investigated in 1982-1990 and no P. braueri was found. The results indicate that high probability of P. megacephalus being an alien species. P. megacephalus has high adaptability and reproductive ability, and its population is still expanding in Taiwan at present. In the future, population control as well as reporting and monitoring by volunteers and the public are important cost-effective conservation measures.