移籠緊迫對領角鴞糞便中皮質酮濃度變化之影響

Effect of Stress from Cage Transfer on Fecal Corticosterone Concentration of Collared-Scope Owls (Otus bakkamoena)

腎上腺皮質酮（corticosterone）屬於固醇類荷爾蒙，受下視丘、腦下垂體所調控，能反應環境壓力與情緒變化，因此又被稱爲「壓力荷爾蒙」。以糞便檢測動物體內的腎上腺皮質酮濃度變化，爲一種非侵入性檢測技術，在野生動物研究領域能成爲論證工具，用以評估環境對動物的影響。本試驗利用農委會特有生物研究保育中心長期收容暫時無法野放的領角鴞進行研究。試驗動物皆經混籠飼養6個月以上，試驗前先隨機收集移籠前之糞便樣本，之後移入隔離籠舍、個別飼養。收集移籠後21天內之糞便樣本，以80%乙醇進行萃取，並以EIA檢測分析，比較移籠前、後糞便中的皮質酮濃度變化，並記錄移籠後的個別進食狀況。結果發現，移籠後的2天內，動物因受到人爲的抓取、檢查與環境改變的緊迫所刺激，皮質酮濃度上升，且多數試驗動物個體有拒食的狀況。移籠後第3~6天皮質酮濃度逐漸下降，個體漸漸適應環境，所有的個體進食狀況漸漸恢復正常。移籠後的第8~21天，期間皮質酮濃度穩定無變化且其值低於移籠前1/3。結果證實，以糞便檢測領角鴞的皮質酮濃度變化，能了解領角鴞對環境改變的生理反應，並發現圈養之領角鴞對新環境之適應期6~8天左右，移籠後的進食狀況可反映出動物的適應狀況。

Corticosterone is secreted from adrenal glands in response to environmental stress and/or emotional arousal. It is regulated by hypothalamic-pituitary-adrenal axis (HPA axis). Its measurement with the noninvasive technique has become an important tool for assessing environmental or other stress in wild animals. In this study we used 14 collared-scope owls (Otus bakkamoena) as test animlas. They were caged together for more than six months and then transferred into individual cages for 21 days. The fecal samples were collected during the pre-transfer period and post-transfer period. Fecal corticosterone concentration was measured with EIA. The food intake was recorded during the post-transfer period. The results showed that a peak corticosterone concentration was found within first 2 days after transfer. All owls showed poor food intake, indicating that the cage transfer caused stress on the owls from handing, examining, and change in cage environment. The fecal corticosterone concentration decreased gradually on the third to sixth day after transfer in response to diminishing in the stress effect. Food intake gradually recovered. The mean corticosterone concentration decreased to a baseline level on the eighth to the twenty-first day after transfer, that was only a third of that prior to transfer. It is concluded that the collared-scope owls needed 6 to 8 days after cage transfer to adapt to a new cage environment.