Whooping
Crane Migration Update: March 26, 2004
Today's Report Includes:
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Where's
the Whooper? Photo OM |
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Crane
#107 turned up March
12 in Tennessee! Photo C& M Kaldenbach |
Whoopers
Overhead! Migration Begins
If you saw our News
Flash last week, you know that migration is underway! Now several
birds in both flocks—-the Aransas/Wood Buffalo flock and the tiny
reintroduced Eastern flock—-are heading for their summer nesting
grounds. At the Chassahowitzka
NWR release pen, the four older ultracranes (#105, 204, 218 and
214) continue to share living space with the sixteen '03 chicks, still
hanging out on their wintering grounds. But by the end of last week,
thirteen of the hatch year '01/'02 ultralight-led whooping cranes had
begun spring migration. ICF's Anne Lacey was able to confirm that male
#106 is already back in Adams County, Wisconsin! What is especially
remarkable about #106 being first? Find out the answer, and learn the
whereabouts of all the other ultracranes, by checking our frequently
updated charts:
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Map
Credit ICF |
When
Will The Rest of the Whoopers Leave? Challenge Question
#5
“Through thousands of years of trial and error, whooping cranes
have learned not to leave too early,” said Tom Stehn, a leader
of the Whooping Crane Recovery Team. Will our young ultralight-led birds
know when it is time to migrate? ICF’s Sara Zimorski explained:
As for most living things, the most important time-keeper is the length
of daylight, or photoperiod. The lengthening days trigger a hormonal
response in the birds. They may also use proximate clues such as temperature
and vegetation changes. As migration time nears, the birds become increasingly
restless, peering up at the sky, flapping their wings, and squabbling
with one another. At Necedah NWR, we also often saw them soaring in
thermals, a technique used throughout migration to conserve energy and
gain altitude.” But don’t you wonder...
Challenge Question #5:
“Why did most of the ‘experienced’ ultracranes leave
so much earlier this year?”
Aransas
Flock on the Move: Challenge Question #6
Tom Stehn sent exciting news about the Wood/Buffalo flock after his aerial
census on March 23. Think about how hard it must be to count cranes from
a small plane! The Refuge consists of over 70,000 acres that attract thousands
of migratory birds.
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Steve
Hillebrand, USFWS |
Tom
Stehn and Pilot |
View
from Plane |
Dear Journey North,
The whooping crane migration has begun!!!! I did a census flight on March
23rd and estimated about 6 cranes had departed. The only two territorial
adult pairs that I couldn't find out of the 69 total wintering pairs were
the Lobstick adults that had brought two chicks with them this fall, and
the Grass Island pair. The Lobstick adults are always one of the earliest
pairs to leave and first to get up to Canada and nest. Hopefully citizens
will report seeing in migration this unusual grouping of two adults with
two young. However, the young have lost most of the rusty brown juvenal
plumage and closely resemble the adults unless one looks closely to see
a little remaining brown on their head and necks. The young are just about
full grown now, although they won't be old enough to mate and raise chicks
of their own for at least 2 more years. The Lobstick family last fall
migrated from Saskatchewan, Canada to Aransas, Texas in 8 days. They won't
make the return trip as quickly since I'm guessing the nesting grounds
will remain covered with ice and snow for several more weeks. They should
complete the 2,400-mile migration in 3 to 4 weeks and be nesting by the
end of April.
Currently there are already hundreds of thousands of sandhill cranes on
the Platte River in Nebraska, and yet only a half dozen whooping cranes
are headed north. Here’s a question for you:
Challenge
Question #6:
Since both sandhill cranes and whooping cranes nest in the far north,
why do whooping cranes migrate about 1 month later than their sandhill
crane cousins? (Hint: The answer involves the time the sandhills spend
on the Platte River.)
(To
respond to this question, please follow the instructions below.)
Tom Stehn, Whooping Crane Coordinator
Try
This! Log the Main Flock’s Spring Departure
A Reminder: The Aransas/Wood Buffalo flock is the only naturally occurring
wild migratory population of whoopers in the whole world, and this entire
flock was down to only 15 birds in 1941. That means every whooper alive
today is a descendent of those 15. Every whooper alive today either hatched
at the Canadian nesting grounds OR is a descendant of a whooper that hatched
there. Now that main flock is beginning the journey north to their nesting
grounds, which they’ve done for centuries. Keep track of this flock’s
spring departures with Tom’s census reports, coming weekly in April:
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Whooping
crane #107 with Sandhill cranes at Hiwassee. Which is which? Photo
OM/WCEP |
Help
For Crane Spotters: ID Practice
With migration underway, would you know a whooper if you saw one? What
traits set cranes apart from other birds? Develop an eagle eye for cranes
with our many photos and tips, here:
Besides the
sites above, there’s a place where EVERYONE can go see cranes now.
Read on!
Crane
Cam on the Platte River
Hooray! “One whooping crane was observed March 8 south of Grand
Island on the Platte River,” came the exciting news from Wally Jobman.
Each spring, Wally reports to us and also compiles migration records for
the U.S. from his USFWS office in Grand Island, Nebraska. The Platte River
is an important staging area for whooping cranes along their migration
route from southern Texas to northern Canada. Every year, thousands of
other birds also rest and forage on the sandbars and estuaries of the
river. People travel from far and wide to see and listen during migration
season. Now YOU can watch the sandhills and (we hope) whooping cranes—-by
clicking on a crane cam on the Platte River!
Wally says,
“The weather for the rest of this week will be in the 70’s
with south winds. Sandhill crane numbers on the Platte will likely peak
this week.” Why are south winds important to migrating cranes?
Are
You Ready for Satellite Tracking? Links to Lessons
With whoopers in the air, you may wonder why we don’t have a map
and satellite data on the Eastern ultracranes this week. The PTT data
we have so far has been sporadic and does not provide a consistent tracking
for any of the cranes. We hope that will change by our next report (one
week from today). Meanwhile, here are some tips and background lessons
to help you get ready for satellite tracking:
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ICF
tracker Lara Fondow.
Photo Laura Erickson |
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Photo
OM |
Tracking
with Radio Telemetry: Challenge Question #7
Every Whooping Crane in the new flock being reintroduced to Eastern North
America wears a leg band with a radio-tracking transmitter. Project biologist
Dr. Richard Urbanek and tracker Lara Fondow keep track of the cranes 24/7
once they are free flying and migrating. How? See photos of Lara’s
tracking vehicle, close-ups of the radio transmitters worn by each crane,
a video of Lara explaining how tracking works, and fun journaling questions:
Then come
back and answer:
Challenge Question #7:
“What percentage of a crane's weight is the transmitter?”
(To
respond to this question, please follow the instructions below.)
Who’s
Calling? Discussion of Challenge Question #3
“Which is the male and which is the female in this photo of the
unison call? Explain why you think so.”
Kris from Grade Two at Ferrisburgh (VT) Central School
said the bird on the left was the male, which is correct. She used clues
from the two birds’ sizes and coloration, which are good for telling
the gender of MOST birds. That was good thinking, but here’s a surprising
fact: a blood test is necessary to be certain of the gender with whooping
cranes!
Mansi, Jessica, George, Nick, Caitlin, Alex, Cheyenne, Sabrina
and Frank, all from Iselin (NJ) Middle School/grade 7, also correctly
said the male was on the left and the female on the right. These students
used clues from the paragraph that described the head position of the
unison-calling cranes. They also used our “Meet the Flock”
charts with information about the gender and leg bands.
Way to go, all of you!
Detectives
Digging Deeper: Discussion of CQ #4
Last time we asked you to dig deeper into reasons for giving PTTs to #301,
#309, and #312 by looking at the 2001 and 2002 history. “What do
the birds who have strayed the most and been hardest to keep track of
have in common? What do you think this has taught the WCEP leaders to
help them choose birds for PTTs?” No one commented that all three
PTT birds this year are females. Let’s hear more about the reasoning,
as told by Heather Ray of Operation Migration:
Cranes 301, 309 and 312 were selected because
(a) They had high social status in the flock.
(b) They were not "trouble" birds....meaning no outward signs
of aggression toward others. For example, personality notes about #312
say she ‘Likes to be part of the group during flights. Gets anxious
if it is a lone crane with one of the ultralights, and keeps glancing
at the main flock as if she would prefer to join them.’ AND, while
#309 began as a very independent youngster, she soon evolved into a dedicated
follower and fit in quite well with the other members of her cohort.
(c) Females in general will wander somewhat IF they are not attached to
a male. The 3 girls that
ventured west last summer were unattached, while all other females
(exceptions #107, #214 and #209) that were associating with males remained
in the vicinity of central Wisconsin, if not directly on the Necedah National
Wildlife Refuge. Male cranes tend to select the future breeding/nesting
territory and bring their chosen females to this territory.
Thanks, Heather!
How
to Respond to Today's Challenge Questions:
IMPORTANT:
Answer only ONE question in each e-mail message.
1. Address
an e-mail message to: jn-challenge-crane@learner.org
2. In the Subject Line of your message write: Challenge
Question #5 (OR #6 OR #7).
3. In the body of EACH message, give your answer to ONE of the questions
above.
The Next Crane Migration Update Will Be Posted on April 2, 2004.
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North. All Rights Reserved.
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