The magnificent
gyrfalcon is the largest and most powerful of the swift-flying falcon
group. Alternate spellings are gerfalcon and jerfalcon (all
three spellings are pronounced the same way - JUR fal kun). The name may
come from a Latin word meaning "sacred falcon," perhaps because
this lordly bird was so admired by medieval falconers. Some researchers
trace the word back to a type of German spoken many hundreds of years
ago. In this language gyrfalcon means "greedy falcon," possibly
because the gyr is such a determined hunter. Once it has begun a chase
it is not likely to give up until it has used its stamina as much as its
great speed to wear out and capture its prey. In falconry's medieval heyday,
the gyrfalcon was the most highly prized of all the falcons, possessed
only by royalty.
This falcon comes in a wide range of colors and patterns,
from a breathtakingly beautiful white variety with dark arrowhead-shaped
markings, through many different shades of gray, to an almost black bird.
In the past the differently colored gyrfalcons were thought to be different
subspecies or even different species (the white variety, because of its
beauty and rarity, was the favorite of falconers). Some older books refer
to three different color "phases" or "morphs," giving
the impression that the gyrfalcon comes in three distinct colors - white,
gray and blackish. Well, it doesn't. The gyrfalcon's various plumage types
can't be neatly divided like that, because they occur in so many different
shades and patterns. Nor are the different colors necessarily found in
separate regions, as people once believed. In northern Quebec, for example,
white, gray and black gyrs all use the same breeding area.
The gyrfalcon is a species of the bleak arctic and subarctic
tundra in the Old World as well as in the New World. The majority of gyrs
will live out their lives in this harsh environment, never venturing south
of the Great Lakes. However, some individuals may winter as far south
as New Jersey, and a few are seen in New England every year. In some years
an unusually high number are recorded because of a food shortage in the
gyrfalcon's northern home. This falcon often preys on other birds. In
coastal areas it will hunt waterfowl like geese and ducks, but the gyr's
staple prey is the ptarmigan, a kind of northern grouse. The gyr rounds
out its diet with mammals like arctic hares and lemmings. Ptarmigan, arctic
hares and lemmings all go through regular cycles of population buildups
and crashes. When prey becomes scarce the gyrfalcon, like the snowy owl
and the great gray owl, drifts south. When a gyr is spotted in New England
it is usually along the coast, where the habitat resembles the falcon's
tundra home. In Western Massachusetts gyrs follow the Connecticut River,
hunting on its flat floodplain. When this rare and dramatic visitor does
appear, birders come from far away to feast their eyes.
Female gyrfalcons are considerably larger than the males,
which is true of other falcon species as well. Females average close to
4 pounds, with a body length of 23 inches and a wingspan of 50 inches.
Males average 2 1/2 pounds, with a body length of 20 inches and a wingspan
of 45 inches. While the peregrine falcon is usually considered the fastest
animal in the world, diving at speeds of around 200 miles per hour, the
gyrfalcon is faster in horizontal flight. It tends to catch its prey after
a chase that may be lengthy. Having worn down its prey, the gyr usually
captures it on the ground, using its powerful, thick-toed feet to effectively
hold down even large prey. The specialized biting beak, a falcon characteristic,
is used to quickly snap the prey's neck.
The gyrfalcon's remote northern home has helped to shield
it from man-made threats such as habitat destruction. Unlike the peregrine,
which disappeared from the East as a breeding bird in the 1960s because
of DDT poisoning, the gyrfalcon has not been affected by pesticides. Although
birds are occasionally shot or meet with accidents when they move into
southern regions, the gyrfalcon's overall population is stable.
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