藉由行為調節體溫對於外溫動物的生存適應有關鍵性的影響,外溫動物常透過行為的方式選擇溫度適合的棲地。許多內在及外在的因素都會影響外溫動物的體溫選擇,因為不同的生理反應其最適溫度值可能不一樣,所以在不同的生理狀態下,外溫度動物偏好的溫度便可能不一樣。此外當外界環境變化時,牠們的體溫也可能隨著改變。本實驗中分別依照內在的懷孕狀態和進食狀況、外在的季節變化,測試菊池氏龜殼花(Trimeresurus gracilis)偏好的溫度,並加上分布於低海拔的龜殼花(Trimeresurus mucrosquamatus),以比較不同的海拔分布對近緣種蛇類體溫偏好造成的影響。 從台灣的各地區採集到蛇後,先在實驗室馴養一段時間才進行實驗。實驗期間為1999年9月到2001年5月。每隻蛇進行溫度選擇實驗前,以L:D=12:12的光週期和20℃的溫度馴化兩週以上。實驗時將溫度電偶固定在蛇的泄殖腔內,蛇可以在溫度範圍為40℃~5℃的溫度槽內自由活動,用溫度自動記錄儀連續紀錄蛇的泄殖腔溫度24小時,結果(1)菊池氏龜殼花和龜殼花的體溫都不因性別、日夜週期或吻肛長而異;(2)秋季懷孕的菊池氏龜殼花,其偏好的溫度是25.5℃,同季節未懷孕母蛇的偏好溫度則是13.4℃,懷孕時菊池氏龜殼花的偏好溫度會顯著高於不懷孕的狀態;(3)菊池氏龜殼花進食後前一小段時間有偏好較高的體溫傾向,而後則漸下降;(4)季節變化會顯著影響菊池氏龜殼花的偏好溫度,在同樣的馴化條件下,夏季的偏好溫度是 20.8℃,而冬季的偏好溫度是14.8℃;(5)比較了菊池氏龜殼花與龜殼花冬、夏季的偏好溫度,冬季的菊池氏龜殼花其偏好溫度明顯低於龜殼花的偏好溫度,但夏季則不具顯著差異。
Behavioral thermoregulation is an important aspect of ectotherms. Many factors may affect their preferred body temperature. The aim of this research is to study the internal and external factors that may influence the thermal preference of Taiwan mountain pit viper, Trimeresurus gracilis, an endemic species of Taiwan, that inhabit only at an elevation over 2000 meters. Besides, I compared the thermopreferrenda of T. gracilis with that of T. mucrosquamatus, a congenera species that inhabit mostly at low elevation. I found sex、daily rhythm and snout-vent length had no influence on the preferred body temperature of both T. gracilis and T. mucrosquamatus. Pregnant female T. gracilis selected a higher body temperature than that of nongravid females. Postprandial thermophilic behavior of T. gracilis was found only at the first few hours after feeding. A significant difference of thermopreferrenda of T. gracilis was found in different season. In winter, T. gracilis selected a significantly lower body temperature than that of T. mucrosquamatus. However, no difference of thermopreferrenda was found between both species during the summer.