I've just come across a recent paper in Nature (1997, 388:64-67)
which describes a considerable reduction of body temperature
during foraging dives in king penguins. Using telemetry to monitor
temperature changes from three recorders in the abdomen, they
showed that temperature reduction was more than just the result
of taking cold fish into the stomach.
During some deep dives some body regions had temps more than 10oC below
that of the stomach, coming down to 19oC compared with a normal body
temperature on land of 38oC.
To quote the authors:
"These temperature decreases, which would lead to a metabolic depression,
might help explain the extraordinary diving performance of king penguins.
This energy saving would also be analagous to that which results from
torpid periods in hibernators,...
Finally, although they are much poorer at diving than penguins,
the best human divers rely on voluntary control of automatic processes by
using techniques such as yoga, these may induce hypometabolism, which according
to our results, is a key process to tolerating an extended breath-hold".
Peter
Dr Peter Woodall email =
Division of Vet Pathology & Anatomy
School of Veterinary Science Phone = +61 7 3365 2300
The University of Queensland Fax = +61 7 3365 1355
Brisbane, Qld, Australia 4072 WWW = http://www.uq.edu.au/~anpwooda
"hamba phezulu" (= "go higher" in isiZulu)
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