棕樹蛇

棕樹蛇
保護狀況
	; 無危（IUCN 3.1）
科學分類
界：	動物界 Animalia
門：	脊索動物門 Chordata
綱：	爬蟲綱 Reptilia
目：	有鱗目 Squamata
亞目：	蛇亞目 Serpentes
科：	游蛇科 Colubridae
屬：	林蛇屬 Boiga
種：	棕樹蛇 B. irregularis
二名法
	Boiga irregularis; Merrem（英語：Blasius Merrem）, 1802
異名
	Coluber irregularis Merrem, 1802; Boiga irregularis Fitzinger, 1826; Dipsas irregularis Boie, 1827; Triglyphodon irregularis Duméril & Bibron, 1854; Dipsadomorphus irregularis Boulenger, 1896

棕樹蛇（學名：Boiga irregularis；英語：brown tree snake）是林蛇屬下的一種樹棲蛇，原産於澳大利亞東部和北部沿海、印度尼西亞東部、巴布亞新幾內亞和美拉尼西亞西部多個島嶼上。棕樹蛇因為入侵關島並對當地鳥類繁衍造成毀滅性的打擊而聞名。^[1]國際自然保護聯盟物種存續委員會的入侵物種專家小組（ISSG）列為世界百大外來入侵種。

特徵與習性

雖然是樹棲蛇，但棕樹蛇也會出現在草地和稀疏林地。在巴布亞新幾內亞，其活動範圍最高為海拔1,200公尺（3,900英尺）。^[2]一般在夜間到地面捕食，白天則躲在樹冠、空木、岩隙甚至是房檐下的陰暗角落裡。^[3]^[4]棕樹蛇一般體長1—2公尺（3.3—6.6英尺），蛇身細長可以迅速通過狹小的縫隙。身體顏色從褐色到黃綠色不等，也有帶紅色斑點的米黃色個體。^[4]可以長期不吃東西。^[4]

食物

棕樹蛇的食物包括鳥類、蜥蜴、蝙蝠和小型齧齒動物。^[5]^[6]因此有時也會襲擊家禽及籠鳥。^[7]

因為缺乏天敵且有豐富的食物來源，入侵關島的棕樹蛇的體型愈來愈大，超過了正常的1—2公尺（3.3—6.6英尺）。^[5]在關島記錄中最大的棕樹蛇可長到3公尺（9.8英尺）。^[5]

繁衍

棕樹蛇的繁衍並沒有得到深入研究。^[5]雌性的會產下4-12枚橢圓形的卵。^[2]^[5]依據氣候和食物豐富程度，雌性每年可產卵一至二次。^[5]產卵地點選擇在空木、岩隙和其他可以抵禦高溫和乾燥的地點。^[5]^[8]某些情況下，雌性棕樹蛇可在交配後將受精卵儲存在體內數年之久。^[4]

毒液

棕樹蛇受到威脅時就會變得極具攻擊性，^[5]在嘴的後部有兩個較小的毒牙，其表面有溝槽。^[9]由於其毒牙並不是中空構造，因此造成咬傷時也只有少量的毒液會進入獵物體內。毒液具有微弱的神經毒性，可能也有細胞毒性。對成年男性影響很小，而兒童會有較強的反應。^[5]^[9]

入侵物種

1952年棕樹蛇突然出現在關島，原因可能是貨船運輸。^[5]^[9]對棕樹蛇來說，這裡有豐富的食物來源，並且在當地除去紅樹巨蜥和野豬之外再無天敵，關島上的棕樹蛇數量開始急劇增加。^[5]造成了許多當地物種滅絕以及數千起斷電等事故，給當地居民的生活造成了相當的不便。^[5]而關島作為西太平洋地區海運樞紐，與其有聯繫的其他諸島因此也面臨著棕樹蛇入侵的威脅。^[5]為解決這一問題，當地政府專門訓練了警犬來搜尋可能藏身於貨船上的棕樹蛇。^[10]不過雖然如此，還是在威克島、天寧島、羅塔島、沖繩縣、迪戈加西亞島和夏威夷發現了其蹤跡，甚至連美國本土的德克薩斯州也有報導發現棕樹蛇。^[11]而塞班島上的棕樹蛇已經有了擴張的跡象。^[5]

現在關島上的棕樹蛇數量已經開始下降，平均每公頃約有30至50條棕樹蛇。^[12]原因可能是食物來源減少及人類捕殺。^[12]

數量控制

目前棕樹蛇有2種天敵已被確認，即紅腹伊澳蛇（英語：Red-bellied black snake）和劇毒的海蟾蜍。此外還有55種潛在的天敵。^[13]但因為其天敵本身侵略性較強，因此引入天敵並不是控制其數量的好方法。^[14]

除去天敵之外，棕樹蛇對薄荷及對乙酰氨基酚過敏，在實驗中含有80毫克對乙酰氨基酚的老鼠屍體可以致死棕樹蛇。^[15]

參考文獻

^ Invasive Species: Animals - Brown Tree Snake （頁面存檔備份，存於網際網路檔案館）, National Agricultural Library, United States Department of Agriculture, Retrieved 2010-08-31
^ ^2.0 ^2.1 Bomford, M; F.Kraus. Predicting establishment for alien reptiles and amphibians: a role for climate matching.. 11:713-724. Biological Invasions. 2008. 缺少或|url=為空 (幫助);
^ Campbell, S.R.; S.P. Mackessy. Microhabitat use by Brown Treesnakes (Boiga irregularis): Effects of moonlight and prey.. 42(2):246-250. Journal of Herpetology. 2008. 缺少或|url=為空 (幫助);
^ ^4.0 ^4.1 ^4.2 ^4.3 Fritts, T.H.; G.H. Rodda. The role of introduced species in the degradation of island ecosystems: A case history of Guam.. 29:113-140. Annual Review of Ecology and Systematics. 1998. 缺少或|url=為空 (幫助);
^ ^5.00 ^5.01 ^5.02 ^5.03 ^5.04 ^5.05 ^5.06 ^5.07 ^5.08 ^5.09 ^5.10 ^5.11 ^5.12 ^5.13 Fritts, T.H.; D. Leasman-Tanner. The Brown Treesnake on Guam: How the arrival of one invasive species damaged the ecology, commerce, electrical systems, and human health on Guam: A comprehensive information source. U.S. Department of the Interior. 2001 [2008-09-11]. （原始內容存檔於2008-12-07）.
^ Pianka, Eric R.; King, Dennis; King, Ruth Allen. (2004). Varanoid Lizards of the World. Indiana University Press, 588 pages ISBN 0-253-34366-6
^ D'Evelyn, S.T.; N. Tauri. Learning-by-catching: Uncertain invasive-species populations and the value of information.. 89(4):284-292(2). Journal of Environmental Management. 2008. 缺少或|url=為空 (幫助);
^ Savidge, Julie, Fiona Qualls, and Gordon Rodda. "Reproductive Biology of the Brown Tree Snake, Boiga Irregularis (Reptilia: Colubridae), During Colonization of Guam and Comparison with That in Their Native Range." Pacific Science, 61.2 (2007): 191-199.
^ ^9.0 ^9.1 ^9.2 Mehrtens, John. Living Snakes of the World in Color. New York: Sterling. 1987. ISBN 0-8069-6461-8.
^ Vice, Daniel. Working Dogs: The Last Line of Defense for Preventing Dispersal of Brown Tree Snakes from Guam. 缺少或|url=為空 (幫助)
^ Kraus, Fred. ALIEN SPECIES. Department of Land and Natural Resources State of Hawaii. 2004 [2008-09-11]. （原始內容存檔於2008-08-02）.
^ ^12.0 ^12.1 Mortensen, H.S.; Y.L. Dupont. snake in paradise: Disturbance of plant reproduction following extirpation of bird flower-visitors on Guam.. 141(8):2146-2154. Biological Conservation. 2008. 缺少或|url=為空 (幫助);
^ Caudell, J.N.; M.R. Conover. "Predation of brown tree snakes (Boiga irregularis) in Australia.. 49(2-3):107-111. International Biodeterioration & Biodegradation. 2001. 缺少或|url=為空 (幫助);
^ Burnett, K.M.; S. D'Evelyn. " Beyond the lamppost: Optimal prevention and control of the Brown Tree Snake in Hawaii. 67(1):66-74. Ecological Economics. 2008. 缺少或|url=為空 (幫助);
^ Engeman, R.A.; M.A. Linnell. The effect of trap spacing on the capture of brown tree snakes on Guam. USDA National Wildlife Research Center. 2003. 缺少或|url=為空 (幫助);

外部連結

Species Profile- Brown Tree Snake (Boiga irregularis) （頁面存檔備份，存於網際網路檔案館）, National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for brown tree snake.

警告：默認排序鍵「Brown Tree Snake」覆蓋了之前的默認排序鍵「Boiga irregularis」。

[1] Invasive Species: Animals - Brown Tree Snake （頁面存檔備份，存於網際網路檔案館）, National Agricultural Library, United States Department of Agriculture, Retrieved 2010-08-31

[Bomford-2] 2.0 ^2.1 Bomford, M; F.Kraus. Predicting establishment for alien reptiles and amphibians: a role for climate matching.. 11:713-724. Biological Invasions. 2008. 缺少或|url=為空 (幫助);

[Campbell-3] Campbell, S.R.; S.P. Mackessy. Microhabitat use by Brown Treesnakes (Boiga irregularis): Effects of moonlight and prey.. 42(2):246-250. Journal of Herpetology. 2008. 缺少或|url=為空 (幫助);

[Fritts,Rodda-4] 4.0 ^4.1 ^4.2 ^4.3 Fritts, T.H.; G.H. Rodda. The role of introduced species in the degradation of island ecosystems: A case history of Guam.. 29:113-140. Annual Review of Ecology and Systematics. 1998. 缺少或|url=為空 (幫助);

[Fritts-5] 5.00 ^5.01 ^5.02 ^5.03 ^5.04 ^5.05 ^5.06 ^5.07 ^5.08 ^5.09 ^5.10 ^5.11 ^5.12 ^5.13 Fritts, T.H.; D. Leasman-Tanner. The Brown Treesnake on Guam: How the arrival of one invasive species damaged the ecology, commerce, electrical systems, and human health on Guam: A comprehensive information source. U.S. Department of the Interior. 2001 [2008-09-11]. （原始內容存檔於2008-12-07）.

[Pianka-6] Pianka, Eric R.; King, Dennis; King, Ruth Allen. (2004). Varanoid Lizards of the World. Indiana University Press, 588 pages ISBN 0-253-34366-6

[D'Evelyn-7] D'Evelyn, S.T.; N. Tauri. Learning-by-catching: Uncertain invasive-species populations and the value of information.. 89(4):284-292(2). Journal of Environmental Management. 2008. 缺少或|url=為空 (幫助);

[Savidge-8] Savidge, Julie, Fiona Qualls, and Gordon Rodda. "Reproductive Biology of the Brown Tree Snake, Boiga Irregularis (Reptilia: Colubridae), During Colonization of Guam and Comparison with That in Their Native Range." Pacific Science, 61.2 (2007): 191-199.

[Mehrtens-9] 9.0 ^9.1 ^9.2 Mehrtens, John. Living Snakes of the World in Color. New York: Sterling. 1987. ISBN 0-8069-6461-8.

[Vice-10] Vice, Daniel. Working Dogs: The Last Line of Defense for Preventing Dispersal of Brown Tree Snakes from Guam. 缺少或|url=為空 (幫助)

[Kraus-11] Kraus, Fred. ALIEN SPECIES. Department of Land and Natural Resources State of Hawaii. 2004 [2008-09-11]. （原始內容存檔於2008-08-02）.

[Mortensen-12] 12.0 ^12.1 Mortensen, H.S.; Y.L. Dupont. snake in paradise: Disturbance of plant reproduction following extirpation of bird flower-visitors on Guam.. 141(8):2146-2154. Biological Conservation. 2008. 缺少或|url=為空 (幫助);

[Caudell-13] Caudell, J.N.; M.R. Conover. "Predation of brown tree snakes (Boiga irregularis) in Australia.. 49(2-3):107-111. International Biodeterioration & Biodegradation. 2001. 缺少或|url=為空 (幫助);

[Burnett-14] Burnett, K.M.; S. D'Evelyn. " Beyond the lamppost: Optimal prevention and control of the Brown Tree Snake in Hawaii. 67(1):66-74. Ecological Economics. 2008. 缺少或|url=為空 (幫助);

[Engeman-15] Engeman, R.A.; M.A. Linnell. The effect of trap spacing on the capture of brown tree snakes on Guam. USDA National Wildlife Research Center. 2003. 缺少或|url=為空 (幫助);

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