2001 Newsletter - The Peregrine Fund

Female Gyrfalcon at her
eyrie after being tracked
by The Peregrine Fund
for nearly a year. Note
satellite-monitored
transmitter antenna
extending from her
back.
Gyrfalcon
Tracking Provides
Valuable Information
Photo by Alberto Palleroni
Gyrfalcon
with satellite
transmitter.
Photo by Alberto Palleroni
Gyrfalcons are the largest of all
species of falcons. They breed
by Kurt K. Burnham in the arctic regions of the
world, feeding on ptarmigan and many other kinds
of birds as well as Arctic Hare and small mammals.
Their prey varies from location to location, and
even time of year, as they take advantage of changes
in abundance and seasonal availability. Plumage
also varies, but not seasonally, as they molt only
once annually. Gyrfalcons nesting in the northern
arctic frequently have light-colored plumage and
some are near white, while those in the more southern
arctic are mostly gray in color. Their plumage
color may offer them an advantage when hunting
prey as more snow and ice occur in the northern
arctic than in the southern.
To breed and survive in the severe arctic conditions,
Gyrfalcons have special adaptations beyond
plumage color. Their legs are covered with feathers
and they have very dense plumage with thick down,
all to hold in body heat. During long arctic storms
they may have to go for days without feeding, and
conservation of energy is important. In the early
spring, and particularly during incubation, temperatures
may be well below zero Fahrenheit.
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