Why
Such Short Daily Flights?
Excerpt
Journal of Ultralight
Pilot Joe Duff
Our
daily migration legs may only last an hour or two and might cover
as little as 40 miles at a time. Why?
Our journeys
are small compared to the daily
flights of wild birds. Normally cranes migrate
during midday when the sun's heat is the strongest and creates thermals (rising
columns or updrafts of warm air). The cranes soar and coast on these "elevators" like
hawks or eagles, seldom flapping their wings. Under good conditions
they
can stay aloft
for
hours, covering hundreds of miles with little effort.
Ultralights Don't Fly Like Cranes
We are not able to fly the way cranes do. Behind the ultralights, birds
must flap their wings to stay aloft—expending
more energy and limiting the cranes to relatively short distances
each day. Instead of using thermals like wild birds, our captive-bred
birds
learn
to use the wing of the aircraft and the wake of air it
creates to "surf" through the sky and ease their workload. This
can only happen
when the air is smooth and the wing remains stable. If we meet
turbulence and the wing begins to bounce around, the birds must move
away and follow
from a safe distance. When this happens they are forced to flap-fly, and
they soon get tired.
Timing is
Everything Our
flights are limited to early morning, when the air is usually calmer.
This helps prevent cranes from soaring
away on thermals—and getting lost.That's also when cooler
temperatures keep the birds from overheating.
Instinct
Takes Over Once these
cranes are free and on their own, they will instinctively fly
like wild birds. They will use thermals
when they make their way north in spring and for all their future
migrations.
Try
This! Journal or Discussion Questions
- Why
are ultralight flights short compared to the distance wild birds
can travel?
- Scan the
second paragraph of Joe's entry above and pick out one sentence that
tells the main idea of the paragraph.
- Joe is
Canadian, so a few words are spelled the Canadian way. Can you find
two examples of Canadian spellings?
- The successful
journey south of the ultralight-led
Sandhill cranes was an example of instruction and instinct combined.
Explain what that means.
Journey North is pleased to feature this
educational adventure made possible by the Whooping
Crane Eastern Partnership (WCEP).
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