An Aircraft-Led Migration: Dress Rehearsal For Reintroduction
(Bill and Joe's Excellent Adventure)
An important migration experiment in the plans to help save endangered whooping cranes
took place in 2000 when a small flock of sandhill cranes were led from Wisconsin
to Florida on their first migration. They were taught to follow an ultralight aircraft
as the "parent crane" teaching them the way. The experiment was a success
when the sandhill cranes not only followed the ultralight to Florida, but returned
on their own to Wisconsin the next spring! The migration project gave encouragement
that the same experiment could be performed starting in 2001 with a small flock of
the sandhills' endangered cousins--whooping cranes. It's part of a plan to reintroduce
whooping cranes to eastern North America, where they disappeared over a century ago.
Follow the migration project--called Operation Migration-- with our highlights
here, or read the entire unabridged journal and see spectacular photos on the Operation Migration Web site. Join ultralight
pilots Joe Duff, Bill Lishman, Deke Clark and the sandhill cranes as they fly from
Wisconsin to Florida in an ultralight at "crane speed" (30 miles per hour)
in 40 days.
HIGHLIGHTS from Operation Migration 2000 With
October 2 and 3, 2000: Liftoff!
October 3, 2000. Liftoff.
Today was just another day for the thirteen sandhill cranes raised at Necedah National
Wildlife Refuge and conditioned to follow the ultralight aircraft of Operation Migration;
a short early morning flight, followed by a lazy afternoon of foraging in the mud.
Oblivious to the buzz of activity taking place just a mile away where a team of biologists,
veterinarians, public relations people and pilots were preparing for the imminent
great adventure. In the pre-dawn light at 6 the following morning the team began
day one of a migration that would end about 1250 miles to the south. Trailers were
hooked up, gear was packed and the three aircraft were flown in from the nearby Necedah
airport to the training area in the center of the pristine wetland. Deke Clark landed
first and positioned himself at the south end of the field. Bill Lishman remained
airborne and circled to the north. I landed and waited outside the pen door until
all were ready and Dan Sprague released the birds.
October 6, 2000: A Dropout
Dan Sprague and Glen Olson spent yesterday looking for the bird that dropped out
of our migration during the first leg. The bird was spotted in an upland stubble
field in the company of two other cranes--one adult and one juvenile. It seems our
bird has been adopted by the adult and has joined the small family group. Number
2 was very close to the wild birds and appeared calm. Dan attempted to approach the
birds in costume and using a puppet and vocalizer, but the wild birds flushed and
our bird went with them. It is interesting to note that Number 2's allegiance to
the wild birds is stronger than to us, despite the short time he has spent with them.
Upon reviewing its history, we realized this was the same bird that had caused us
concern over the entire summer. Always a loner, it would often break away from the
aircraft, many times taking other birds with it. On one occasion, it left the flock
and headed back to the pen. We decided to let it go and I radioed a warning to Dan
that it was on its way back. Dan reported that it had just flown overhead and kept
going. It returned on its own but not for several hours. This kind of independent
behavior should have warned us that he was not suited for this study. Every year
we seem to run into this situation, one or more birds are too aggressive and will
not follow the aircraft or are so submissive that they are afraid of it. These birds
are normally removed and used as breeding stock or released with wild birds.
|When the cranes first started out on this migration trip, their flight endurance
was only about 30-45 minutes. In past migration studies, Joe and Bill discovered
that cranes' endurance time increases greatly with each flight as they build their
wing muscles. Of course a nice tail wind courtesy of Mother Nature always helps.
October 10, 2000: Crane Costumes and Secrecy
Crane and "Puppet"
The reason exact location details can't be provided is because this flock of cranes
was raised using a strict costume rearing protocol. As such, they have never seen
nor heard a human. The crew has gone to great lengths to ensure that the birds do
not have an opportunity to see people. This will greatly help them to remain as wild
as possible yet still willing to follow the ultralight aircraft. [See October
17 entry too.]
October 12, 2000: Headwinds!
At 9am CST the flight crew landed in Morgan County, Indiana. Bill reports the time
it took to cover the 43.1 miles from the previous location to be 1 hour and 47 minutes.
To give you an idea of the effect a headwind can have: Yesterday morning the flight
lasted 1 hour and 45 minutes and they covered 85 miles.
The birds performed beautifully, flying in a long line off of Joe's right wingtip.
While speaking briefly with Joe yesterday he remarked to me "this is the best
flock of cranes we've ever had. I feel they would follow us anywhere we ask them
to." Could the reason for this be that for the first time, we are actually communicating
with the cranes in their own language?
We are grateful to Bernhard for now allowing us to speak "Crane-glish."
Note: Read about Dr. Wessling's fascinating discoveries about the language of
crane calls and how this work can help in efforts to save endangered whooping cranes.
October 13, 2000: A Little Lesson
At our highest level, I was able to watch the birds change lead a number of times.
Number 4 always tries to steal the front position preferring to fly within inches
of the wing tip. He is not aggressive enough to push his way in but has now discovered
a new method of procuring the point. He speeds up and flies under the wing, very
close to the cockpit as he passes the aircraft. He climbs up to fly on the pillow
of air that is created in front of the wing and in a slow, gentle drift he slides
down to the wing tip placing himself in front of the lead bird who has no choice
but to take up the second position. This is ingenious and we applaud his initiative
but it is also dangerous. Above the wing are a number of wires, critical to the structure
of the aircraft, which can act as a trap for a bird that has become too cocky. I
cringe every time he passes in front of me and hold my breath as he slides past the
threat, getting away with it one more time. So when he is safely out at the tip,
riding his favorite air, I hit him with the wing just enough to spoil his fun.
October 14, 2000: Number 5 in the Lead
The birds found their cadence and all began to surf on the wake of the aircraft.
For long periods they hardly flapped their wings and I finally had the time to study
Birds #4 and #5 were the first to learn to fly with the aircraft early in the season
and have been dedicated followers ever since. . . .Now high above the cornfields
of Illinois, it is these two birds that most often lead the flock, flying closest
to the wing tip. Number 5 is one of our smallest birds but she still prefers the
Although we were still only flying at 35 mph the mass of air in which we were doing
it was also moving south. The combined speeds added up to 55 mph over the ground
and we cruised along, happily covering the longest distance.
October17, 2000: No Talking, No
Sneezing, No Human Sounds Allowed!
The pilots and handlers always wear costumes while in the company of the cranes.
The costume is designed to mask the human form. Head, face and hands are all covered
while wearing the costume. The baggy gray fabric extends to below the knee so that
"legs" cannot be distinguished. Imagine wearing this garb during the summer
heat that Wisconsin is known for.... Imagine trying to fly an ultralight dressed
like this.... Don't forget! No talking, sneezing, or coughing. Nothing "human."
The only voices they have heard are those of other sandhill cranes, played to them
through a hand-held CD player or loudspeakers mounted on the ultralights.
October 20, 2000: Off Schedule
It seems we are now paying dearly for the tail winds we enjoyed earlier. It is now
day 17 and we predicted this trip would take 32 days. Unfortunately, we are not yet
halfway, but then again ours is a human schedule, based on missed families and costs...
It is not one that applies to birds.
October 25, 2000: Halfway Today!
They've reached Tennessee! The crew departed their last Kentucky location under clear
skies early this morning and after a 45 minute flight covering 25 miles, landed safely
with the cranes in Fentress County, TN. According to calculations, they have covered
statute miles to date, which means they have officially made the halfway point of
this long journey.
October 28, 2000: A Tough Climb
Most aircraft rates of climb are calculated in the hundreds of feet per minute with
ours able to achieve between 750 and 1000. Anything that climbs at less than 250
fpm is considered more of a "stone" than an aircraft, but our birds are
only able to accomplish a sustained climb of about 100 feet every couple of minutes.
This makes crossing a 1500-foot ridge in only a few miles painful but the birds were
up for the challenge. They worked hard and with the wind at our back, as it lifted
to pass over the ridge, so did we.
October 29, 2000: Down Like a Stone
Once the cranes decided it was safe to land they came down like stones. When cranes
need to loose attitude quickly, they drop their legs until they are almost standing,
their wings work more like brakes and they begin to plummet. It is a fascinating
display to watch at a few hundred feet up as they sail by us almost vertically. They
will often look over at us as they pass wondering what is taking us so long.
October 30, 2000: Songbird Sight
Reached Georgia! Against the early morning sun we could see a small flock of songbirds
heading south. In silhouette we could not identify them but we were slowly overtaking
them. Once they noticed us, we must have been perceived as a threat and their defense
was to dive for the ground. They closed their wings and descended at an astonishing
speed. In seconds they disappeared below us. Unfortunately, the birds are so agile
and leery of us that we could not get close enough to identify the species.
October 31, 2000: Aren't We There Yet?
The cranes have now covered some 790 miles since departing Necedah National Wildlife
Refuge in Wisconsin on Oct. 3rd and have approximately 275 miles remaining before
reaching the final destination in Florida.
From previous studies, we believe that birds do not use landmarks as navigation
aids and it is a good thing. With all the fog we have had and the low level of many
of our flights the birds have seen little of the last three states.
November 2, 2000: The Challenges of Operation Migration
By far the most difficult part of this study is managing the experiences of the birds.
It was difficult enough at Necedah National Wildlife Refuge when the pens were miles
away from any human influence and the entire area was closed, but "on migration"
our problems multiply. We need landing sites about every fifty miles. If we have
head winds, like we have for the last few weeks, they are required at 30-mile intervals.
Our shopping list for a stopover site is short but demanding. If we could custom
build them, they would be at least a mile from the sound of traffic and out of sight
of buildings or any other human equipage. They would be in open country with an upland
feeding area and a lowland roosting spot, all beside a grass runway as smooth as
a bowling green with a hangar just over the hill. Some biologists have questioned
our prudence when we are not satisfied with areas that are frequented by wild sandhill
cranes but wild birds have advantages that ours do not. The birds we raised are neither
tame nor wild. Like any creature, they have a natural fear of the unknown but the
rest is a learned response and our ability to teach them is severely limited.
During any crisis, a birds immediate reaction is one of either "fight or flight"
with the latter, by far the safest. Just when to take to the air or how large a buffer
zone is needed is learned from the actions of the adult. Acting as surrogates, we
are the adults but are unable to take off immediately at the first sign of trouble,
or even to properly convey the message that there is reason for concern. If we lead
our birds to an area that appears to be safe but a curious farmer or hunter gets
too close, we have no option but to accept the intrusion, where a wild bird would
fly off to a safer distance if only to return later. The actions of the wild bird
teach its young to keep its distance, while our actions encourage tolerance.
Because we can only teach our cranes the bare minimum in human avoidance, we need
to rely on their natural fear of all things unknown. Our only option is to ensure
that all things human remain unknown and if this makes us cautious, we accept that
label, as long as it keeps our birds wild.
November 3, 2000: A Death
When Dan and Rebecca entered the pen shortly after the experimental flock departed
this morning, they found that one crane had died. The team believes this bird was
somehow traumatized, earlier this morning and as a result, was fatally injured while
inside the pen. This is all we know at this point. Though regretful, the death of
a bird does not affect the integrity of this sandhill crane migration study. It is
not uncommon to have some loss in a scientific study.
The crew and birds flew the entire 62 miles and are now situated in Dougherty County,
GA. Just slightly over 200 miles remaining.... Go Team Go!
November 6, 2000: Getting
They are now in Gilchrist County, FL., after a rather bumpy flight this morning that
lasted 1:15. Joe said they had to stay very low, about 100ft. as at higher altitudes
the air was just too warm and the SE headwind was horrendous. He said that his arms
are very sore and Deke is walking around rubbing his own shoulders too. They are
currently waiting for the ground crew to arrive to set up the temporary pen.
November 11, 2000: End
of the Trail!
This migration ended successfully when two ultralights landed at the St. Martins
Marsh Aquatic Refuge in Florida with 11 cranes on the 11th day of the 11th month:
Veterans Day in the United States and Remembrance Day in Canada. Using the information
gathered, we hope to show the same migratory route to the world's long-awaited, first
reintroduced flock of migratory whooping cranes in 2001 (pending government approvals).
[NOTE: Approvals granted in spring, 2001.]
|"They were collected as eggs from the wild and they have been returned. If we've
done our job right, they will maintain their wildness and not be attracted to humans.
Our influence will have been minimal, as it should be. They will be wild birds, but
with a good memory of a summer home and a strong sense of how to return to it."
Joe Duff, Team Leader, Lead Pilot, and Co-Founder of Operation Migration
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