Comes at a Cost
By Joe Duff
Duff works on crane decoys at Patuxent WRC.
Photo Jane Duden
May 12, 2005, the WCEP Tracking Team announced that the remains
of #414 were found in Juneau County, Wisconsin. Feathers and bone
large area, indicating a full-size predator killed the birds.
A High Death Toll in One Year
unfortunately brings to 7 the number of birds lost in the year 2004-2005.
It also brings many of us to our knees. We spend so much
time nurturing our birds, doggedly adhering to a restrictive protocol,
despite our best attempts to think of them as wild animals, we
still become attached. There is satisfaction in maintaining a costume-rearing
discipline and the entire team takes pride in the fact that none
yet been tamed. They avoid human environments preferring natural
habitat, and appear to be truly wild, but wildness comes at a cost.
for the untamed are harsh, and the consequences final. If we
want our birds to be wild we must accept that they face real hazards.
How to Avoid Predators?
Still the mortality is so high this year that we can't help but become
introspective and question the methods we use to prepare them for release.
It may be time to give serious thought to developing and instituting
a predator avoidance protocol, or at least become more adept at teaching
them the value of roosting in water sufficiently deep and far enough
from shore to keep them safe during the night. There must be some way
to keep them vigilant and instil in them a natural fear of furry things
with teeth. The problem is that being surrogates, we are at best, marginal
Without being taught, our chicks somehow develop a social structure
as do wild birds, and instinctively they understand the meaning of
the adult calls. We carry digital recorders to broadcast these calls,
but our repertoire is limited, and our ability to use them appropriately
restricted. It's like teaching a foreign language when you only know
6 words. If wild parents led their chick too close to a danger area
and were attacked, they would take to the air and immediately teaching
their offspring to be vigilant, what danger areas to avoid, and to
take flight at the first sign of trouble. If we set up a similar scenario
we could stage the approach of a simulated predator and sound the alarm
call but we can't run fast enough to make an proper escape nor can
we get instantly airborne. And if this replicated attack is not carried
out with enough vigour to seriously scare our charges, they might simple
stand in surprise and our imitation predator would have no choice but
to stop short of causing injury. If you charge an enemy to frighten
it off and it doesn't run, what then? The lesson learned by our chicks
would be confusing at best and tolerance to predators at the worst.
Over the course of the summer season our birds learn to water roost
in their overnight pens and we keep it deep enough to teach the
proper lessons. However during the migration it is impossible to find
sites with aircraft access at each location, so they are forced
to roost on dry land. They are protected by the pen but this experience
teach complacency. We hope the lesson is relearned during their
stay at the release pen in Florida, but last year that was a problem.
birds from previous years checked in on this pen before moving
on to better habitat. Their interaction with the juveniles was often
that the young birds were moved into a top netted enclosure that
had no provision for water roosting. This experience may have led to
but that would not explain the death, by predator, of older birds
that by now should know better.
The Way of Things Wild?
ever the cause, it will keep us up at night and you can be sure it will
dominate the discussions around the camp. We will
try our hardest
of fix it, but maybe it is just the way of things wild.