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Kooyman's research has provided much of the existing
information regarding the natural history of emperor penguins. Until recently,
scientists thought that these flightless aquatic birds remained relatively
close to their home colonies throughout their lives. However, Kooyman has
discovered that the birds swim all over the Ross Sea--an area the size of
France--in search of food, typically fish.
About every other year, Kooyman's research team
camps out on the ice, often at McMurdo Sound on the frozen Ross Sea, for
ten weeks from October to mid-December (the antarctic summer) with support
from the National Science Foundation's
Polar Programs.
In hopes of understanding the range of this species,
Kooyman’s group uses special instruments to track the wanderings of emperor
penguins via satellites, while other instruments and underwater videos are
used to calculate swimming velocities and determine behavior. In addition,
penguins’ physiological responses to diving stresses are being studied.
Emperor penguins can make dives of at least 22 minutes and can exceed 1,500
feet depths (460 meters), according to Kooyman’s data.
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Gerald Kooyman in the field
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The object of his physiological
studies is to understand how these birds are managing their oxygen stores.
“This is something,” Kooyman points out, “we don’t understand very well
for any diving animal.”
During his career, Kooyman has made significant
contributions to science in Antarctica, including introducing the use
of time-depth recorders to measure depths reached by diving animals. The
recorder is a tiny electronic instrument package that can be glued onto
a penguin’s feathers like a backpack. It logs the duration and depth of
each dive the penguin makes while recording its heart rate. There is a
radio transmitter that is used to locate the bird and retrieve the instruments
when it returns from foraging for food. If they are not recovered, the
packs will fall off when the bird molts. Kooyman's research team has captured
the record depth for an emperor penguin dive: more than 1,640 feet (500
meters).
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