Why Not Truck
the Birds on No-fly Days?
By Joe Duff
Photo Bev Paulan
|
When
weather delays add up, do you wonder why the team doesn't just
put the birds in crates and truck them to the
next stop? See what Operation
Migration pilot Joe
Duff says:
Cranes Must Be Taught Their Migration Route
With many
species the idea of trucking them to the next stop would work perfectly.
Pigeons have a homing instinct that is almost infallible, and other
birds seem to know their migration route through some sort of genetic
instinct. But it is apparent that at least geese, swans and cranes
learn it by following their parents. As surrogates [substitute
parents], we pilots assume that responsibility.
How
Cranes Navigate
It is my belief, based strictly on my own observations, that
our birds need to experience the migration first hand. We
know from
earlier work that landmarks do not play a critical role in their
ability to navigate,
but the method they use is still a mystery. Likely it is a combination
of factors with no one guidance system that reliably gets them
back. Unlike humans they are not subjected to artificial
stimulants that remove
us from
our environment. They don’t ride in cars or live in buildings. Once
they are transported [before they can fly] to Wisconsin, they
spend their entire lives outdoors. They see the sun rise every
day from the same direction and they
only move under their own steam. It seems to me this would give
them a better sense
of direction than ours.
Breaking
the Chain of Knowledge
Maybe it’s as simple as that; they know where they are because
they got there themselves and that chain of knowledge is broken when
they are put in crates and transported somewhere unfamiliar.
When
Boxes Help
At times we have been forced to transport birds in crates to the next
stopover. Fatigue may cause them to drop out, or some unexplained reluctance
keeps one or more of them from leaving the pen with the rest of the birds. That happened at the beginning of the 2006 migration. On each migration some of the birds make the
entire trip and the others have only missed a leg or a few sections.
During the return journey they often fly as a group, and maybe their combined
knowledge is what gets them home.
2014: A Bold Plan for a Big Challenge
On the 2014 migration, we had a real learning opportunity. With only 52 miles gained in 34 days and a grim weather forecast in Wisconsin, the team made a bold plan. We boxed the birds on November 13 and drove them 600 miles to Tennessee to resume migration flights. Different weather patterns on the southern half of the migration route usually speed the migration along. We worried and wondered: Once they migrate next spring back to where they were unloaded from the long drive, would they instinctively fly due north the rest of the way? Or would they join up there with older cranes and follow them? five crane-kids failed to find their way home after an older crane serving as their "leader" 5-12 left them on April 7, and the team decided it was time to jump in. These birds were later captured, loaded into the tracking van and driven to Wisconsin throughout the night when they would normally be roosting quietly anyway. Then we had to wait and see: How would they do on their first unaided journey south in fall 2015? [Details about each of the Class of 2014's first unaided migrations are on the birds' bio pages.]
What
Works, What Doesn't
We do know that while taking them south in crates does not work, leading them
there does. We are not prepared to risk their ability
to migrate, simply because we have been stuck for days with un-flyable weather.
This project is not about the people on the team — it's about the birds.