領角鴞的僵直姿勢是否具有偽裝功能

Does concealing posture in Collared Scops Owl (Otus lettia) have masquerading function?

陳宏昌(Hung-Chang Chen)

指導教授 ： 孫元勳 博士

國立屏東科技大學/農學院/野生動物保育研究所/碩士(2013年)

https://doi.org/10.6346/NPUST.2013.00011

摘要

一些貓頭鷹遇到威脅時身體會拉長呈現僵直姿勢，推測功能可能和躲避天敵和避免小型鳥類的群聚騷擾，只是尚未有研究加以驗證。本研究以也有此行為的領角鴞(Otus lettia)，測試僵直姿勢是否具有偽裝效果。研究地點在屏東科技大學校區和鄰近的造林地，其中躲避天敵實驗是在樹上隨機擺放1個領角鴞僵直或休息姿勢的標本，由82位受訪者指認；騷擾實驗有21個樣點，兩種標本在每個樣點內隨機輪流擺放，並以行車記錄器拍攝小型鳥類對兩種標本的騷擾行為。結果顯示受訪者尋找僵直姿勢標本所花費的時間較長，且較易把僵直姿勢標本誤認為樹枝。小型鳥類對僵直姿勢標本的騷擾次數明顯低於休息姿勢標本，而且發現僵直姿勢標本的花費時間也較長。12種出現騷擾行為的鳥類中，白頭翁(Pycnonotus sinensis)為騷擾頻度最高的物種。

關鍵字

領角鴞 ； 反捕食行為 ； 僵直姿勢 ； 偽裝 ； 群聚騷擾

並列摘要

Researchers have found that owls would change their body shape from oval to tall and slender while sensing danger. It was hypothesized that the change in body shape would help them avoid attack from predator or mobbing from small birds, yet it has not been tested. We tested the functions of such behavior in the Collared Scops Owls(Otus lettia) using two types of specimens, oval and tall/slender, on the campus of Pingtung University of Science and Technology and nearby forest plantation. A total of 82 persons were asked to search one of the specimens in trees in six minutes. When testing detection by preys, we exposed the two forms of specimens alternately at each site and recorded any mobbing behavior using an event data recorder. We found human testers spent more time looking for the elongated specimen than for the non-elongated one. More people misidentified the elongated specimen as a branch than non-elongated one. The number of mobbing event directed at the specimens is significantly lower for the elongated specimen than for the non-elongated one. We also found birds spending more time searching for the elongated specimen than for the non-elongated one. Chinese Bulbul (Pycnonotus sinensis) is the species which showed the highest mobbing frequency among the 12 species of birds participating mobbing.

並列關鍵字

Collared Scops Owl ； antipredator behavior ； concealing posture ； masquerade ； mobbing

參考文獻

林文隆 (2003) 台灣中部森林領角鴞繁殖生物學初探。台灣猛禽研究1:29-35。

黃光瀛、劉小如、林曜松 (2008) 鳳頭蒼鷹(Accipiter trivirgatus)於鑲嵌森林地景中之食性及與共域台灣松雀鷹(A. virgatus)之區隔。林業研究季刊30:45-56。

謝漢欽、陳弘毅、張鈞媛 (2009) 從統計分析看台灣的平地造林地-以2002年至2005年整合平地造林地地理資訊為例。林業研究專訊16:10-22。

Blancher, P. J., and R. J. Robertson. 1982. Kingbird aggression: Does it deter predation? Animal behaviour 30:929-930.

Brower, J. V. Z. 1958. Experimental studies of mimicry in some North American butterflies: Part I. The monarch, Danaus plexippus, and viceroy, Limenitis archippus archippus. Evolution 12:32-47.