澳大利亞研究人員最近通過田野調(diào)查發(fā)現(xiàn),，在幫助小型哺乳動物度過寒冬方面,，蟄伏可能同冬眠一樣重要,。蟄伏能將動物的能量消耗減少90%,，推翻了以前實驗室得出的只能將能量消耗減少30%的結(jié)論。該研究1月5日發(fā)表在《自然科學》（Naturwissenschaften）雜志上,。
蟄伏是一種介于睡覺和完全冬眠之間的狀態(tài),，在此期間，動物的身體溫度明顯下降,。此前的實驗室觀察認為,，日常蟄伏只能將能量使用降低30%,，蟄伏不過是一種破釜沉舟的保存能量技術(shù)，野生動物很少會使用,。
研究人員在8個長尾袋鼩上安裝了配備無線電廣播發(fā)射機的溫度計，以測定動物們的蟄伏情況,，研究為時4周,。結(jié)果發(fā)現(xiàn)，長尾袋鼩幾乎每晚都會蟄伏,，蟄伏的時間和深度取決于氣溫———在最寒冷的夜晚,，蟄伏時間最長的動物，體溫最低,?？偟膩碚f，它們平均每天蟄伏11個小時,，是實驗室數(shù)據(jù)的2倍,。
研究人員計算發(fā)現(xiàn)，通過日常蟄伏,，長尾袋鼩能夠?qū)⒛芰肯臏p少90%,，與通過冬眠降低的能量相當。該項研究證明,，以前的實驗室觀察嚴重低估了在野外的觀察結(jié)果,，是否其它動物也依賴蟄伏來過冬還需要進一步研究。（生物谷Bioon.com）
生物谷推薦原始出處：
Naturwissenschaften,，doi：10.1007/s00114-008-0492-7,，Gerhard K?rtner，F(xiàn)ritz Geiser
The key to winter survival: daily torpor in a small arid-zone marsupial
Gerhard K?rtner1 and Fritz Geiser1, 2
(1)Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, 2351, Australia
(2)Zoology, University of New England, Armidale, NSW, 2351, Australia
Abstract Mammalian hibernation, which lasts on average for about 6 months, can reduce energy expenditure by >90% in comparison to active individuals. In contrast, the widely held view is that daily torpor reduces energy expenditure usually by about 30%, is employed for a few hours every few days, and often occurs only under acute energetic stress. This interpretation is largely based on laboratory studies, whereas knowledge on daily torpor in the field is scant. We used temperature telemetry to quantify thermal biology and activity patterns of a small arid-zone marsupial, the stripe-faced dunnart Sminthopsis macroura (16.9 g), in the wild and to test the hypothesis that daily torpor is a crucial survival strategy of this species in winter. All individuals entered torpor daily with the exception of a single male that remained normothermic for a single day (torpor on 212 of 213 observation days, 99.5%). Torpor was employed at air temperatures (T a) ranging from approximately ?1°C to 36°C. Dunnarts usually entered torpor during the night and aroused at midday with the daily increase of T a. Torpor was on average about twice as long (mean 11.0?±?4.7 h, n?=?8) than in captivity. Animals employed sun basking during rewarming, reduced foraging time significantly, and occasionally omitted activity for several days in sequence. Consequently, we estimate that daily torpor in this species can reduce daily energy expenditure by up to 90%. Our study shows that for wild stripe-faced dunnarts daily torpor is an essential mechanism for overcoming energetic challenges during winter and that torpor data obtained in the laboratory can substantially underestimate the ecological significance of daily torpor in the wild.
