- Scientists have found the first tropical mammal that
hibernates through hot winter months, when temperatures can fluctuate around
an average of 30C.
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- The Madagascan fat-tailed dwarf lemur (Cheirogaleus medius)
spends up to seven months of the year asleep in a tree hole, rivalling
the hibernating abilities of northern mammals.
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- A research team led by Kathrin Dausmann of Philipps-University
in Marburg, Germany, found that the lemur - a nocturnal primate - hibernates
in poorly insulated holes where the ambient air temperature can vary wildly.
Field studies found that the body temperature of the lemur during hibernation
varies to an extent previously not known in mammals.
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- The findings, reported in the journal Nature , suggest
that the lemur hibernates in order to allow its body temperature to fluctuate
with the environment rather than trying to control it with its own metabolism,
which it has to do when awake and active.
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- Lemurs who did manage to find well-insulated tree holes
seemed to be aroused from their slumber at regular intervals and did not
experience such wildly varying body temperatures. This may indicate the
hibernation was a way of avoiding the temperature extremes experienced
in the tropics.
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- "To our knowledge, our findings are the first physiological
confirmation of prolonged hibernation by a tropical mammal as well as the
first proof of hibernation in a primate," the researchers write.
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- © 2004 Independent Digital (UK) Ltd http://news.independent.co.uk/world/science_technology/story.jsp?story=534611
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