D I S T I N C T LY M O N TA N A • W I N T E R 2 0 1 6
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Photo taken between Madison Junction and Lower Geyser Basin along
Firehole River in Yellowstone when the temperature was well below zero.
Birds have a thick layer of downy feathers which repels water and
insulates them against the cold. e feet of trumpeter swans and other
waterbirds don't freeze in water because of something called counter-
current heat exchange. Warm arterial blood flowing to their feet warms
the venous blood returning to their body. is means that blood flowing
to their feet is relatively cool and the temperature difference between
the water and their feet is small so they lose only a little heat to the wa-
ter. eir feet remain just warm enough to avoid frostbite. Sometimes
they stand with one foot tucked under the bellies to warm it up.
Active on the ground and in trees feeding on voles, squirrels,
snowshoe hares, mice, shrews, berries and birds. Pine Marten
p
p
photo by
RICK
SHEREMETA
photo by
CINDY
GOEDDEL
