Loon Magic/Loon Magic - Wayzata Technology (8011) (1993).iso/mac/mac text/03 Close Look - Flight

Text File | 1993-07-20 | 5KB | 91 lines

   Flight

   Even with a large wingspan of up to fifty-eight inches, common
loons still have a body weight disproportionate to their wing area.
Olson compared the loon's wing area with its weight and found the
ratio to be 0.5 compared to a 8.87 ratio for the golden crowned
kinglet. While this doesn't mean that it is seventeen times easier for
the kinglet to get off the ground, it does reveal the loon's flying
handicap. In his book Birds of the World, Oliver Austin underscored
this point by observing that loons have the " ...least wing surface in
proportion to their body weight of any flying bird." In 1957,
researcher D.B. Savile graphically described the loon's flight: "The
common loon is a flying anachronism. It has an appallingly high wing
load and very inefficient wing form  ... it takes off only with great
difficulty, after a long run and climbs shallowly."

   How long is that run? While loons sometimes need up to a quarter
mile of aquatic runway, they can be more efficient. In his classic
Handbook of North American Birds, Ralph S. Palmer reports common
loons taking off after a twenty-yard run. While wind is a factor, it is
not needed (contrary to loon folklore) to get the birds off the water.
One calm summer day in northern Wisconsin, I watched a pair of
loons take off from a small lake, marking the distance with
prominent landmarks. Later, using detailed maps of the lake, I
estimated the distance from the first "step" to breaking contact with
water at about eighty yards. There are probably many variables
involved here, but the individual loon's capability is, no doubt, the
most important one.

   Getting off the water, however, does not get a loon safely away
from the lake. The ascent of a loon's flight is quite gradual, often
forcing the bird to circle a lake to get over the treetops. On many
small lakes, loons fall into routine flight patterns, curving around
part of the lake and heading over the trees at a fairly predictable
spot. When flying, the feet are extended straight back and held close
together. The flight is not silent.

   On a canoe trip in Ontario's Quetico Provincial Park, my wife, Pat,
and I were on the water at dawn on a foggy morning when a pair of
loons flew toward us just a few feet off the water. About fifty feet
from the canoe, they flared slightly to our left and passed us at eye
level only fifteen feet from the canoe. In twenty years of camping
and canoeing in loon country, I had never been so close to flying
loons, or so awed by any natural sight or sound. The wings cutting
through the air created a sound much louder and more dramatic than
the whistling of mallard wings or that of any other bird I've heard.
Unlike those of other large birds like geese, cranes or herons, a loon's
wing beats are very rapid, about 250 beats per minute.

   The speed of flying loons is surprisingly fast. While most bird
books still list the common loon's flight speed at 60 mph,
contemporary researchers place the speed substantially higher. New
York biologist Paul Kerlinger has estimated ground speeds (taking
into account following winds) of 93 mph during spring migration and
108 mph during fall migration. The average air speed (not counting
the help of wind) was 75 mph. A physician flying his airplane near
Charlotte, North Carolina, had his small plane at nearly full throttle
while watching a loon pull away. He estimated the loon's speed at
100 mph.

   Arthur Cleveland Bent, in his Life Histories of North American
Diving Birds, was superbly expressive describing the loon's flight:

   "The lines are perfect; the strong neck and breast, terminating in
the long sharp bill, are outstretched to pierce the air like the keenest
spear; the heavy body, tapering fore and aft, glides through the air
with the least possible resistance; and the big feet, held close
together and straight out behind, form an effective rudder. The flight
of a loon is decidedly distinctive; such a rakish craft, long and
pointed at both ends, could not be mistaken for anything else."

   It's obvious Bent did not have a graduate school committee looking
over his shoulder; his rich prose is a rarity in scientific literature.

   A loon's transition from air to water is nearly as exciting as that
from water to air. Described by Olson as graceful, perfect seaplane
touch-downs, loon landings begin with a long set-wing glide before
their landing gear drops to drag the water for a short distance and
end with full braking with their breasts. If there is a wind, loons, like
all waterfowl, will land into it.

   Not all landings are picture perfect. Some loon watchers have
witnessed total wipeouts. Paul Strong, a biologist with the Sigurd
Olson Environmental Institute of Northland College and Director of
Wisconsin Project Loon Watch, has seen some dandies with wings,
legs and neck going in several directions at once. Coming in as fast as
they do, even minor landing errors can provide comic relief. Loons
often dive immediately after landing, perhaps to check the area for
danger. After a quick underwater exploration, loons surface and
usually perform a couple of wing flaps before settling down.