Whooping
Crane Migration Update: March 12, 2004
Today's Report Includes:
News
Flash!
Just today, Wally Jobman of the U.S. Fish & Wildlife Service reports,
"It appears that we have one bird on the Platte River in Nebraska."
Is spring migration beginning for the Aransas/Wood Buffalo Flock? More
next time!
Field
Notes from Florida: All’s Quiet
If you took our “Meet the Flock” quiz last week, you’ll
be interested to know that all chicks except 302, 304, 306, 307 and 317
have now attained their adult voices. Many of the chicks are also developing
their red patches, reports ICF’s Crane specialist Sara Zimorski.
“There are still 20 birds at the Chassahowitzka
pen site. Sixeen are 2003 chicks and four are older whoopers (#105, #204,
#218 and #214) from 2001 and 2002 ultralight-led migrations. The trio
of subadults (#105, #204 and #218) are still being aggressive toward the
chicks and trying to defend the feeding station, but the aggression is
much less than it used to be. Some of the male chicks are even starting
to chase and be aggressive towards the adult females.” And even
though sandhill cranes have departed in large numbers for the journey
north, the ultralight-led cranes wintering at other Florida sites are
staying put. Wait! That may not be true for one of them. What’s
new with Crane #106? (See Meet
the Flock 2001) Sara tells us that independent female #107 has not
been found and she may have moved out of FL with migrating sandhill cranes
heading north. She also says, “Things will get more interesting
in the coming weeks. Talk to you later!”
Sara’s
Photos and Your Journaling Questions
Sara again spent much of the winter on site at the pen. She shares
these great photos and comments with you!
“This
is obviously of the heads of two of the adults. I love this picture
because the red patches on their heads are so large and so red. It's
because they were acting very territorial and threatening to us (in
our costumes) when we entered the pen. These birds aren't as close
as they seem; I used the zoom lens on the camera to zoom in on their
heads.” |
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Journaling
Question:
“Why is a red head patch (it’s NOT feathers!) a useful adaptation
for a whooping crane? What other head adaptations help cranes survive?”
See Adaptations That Help
Cranes Survive. (Click on “Head.”)
"This
picture shows some of the chicks flying back into the pen. When we
arrived at the blind that morning, the 4 adults were inside the pen
and the 16 chicks were outside. When the costumes entered the pen
the chicks got excited or anxious and clearly wanted to come in. After
a few minutes of calling and walking around, they all took off and
landed inside the pen and came over to us and to the feeders. I think
they felt bolder and braver about coming in and trying to eat when
we were in there, because the adults defend the feeders and often
chase the chicks away from them.” |
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Journaling
Question:
“Notice the posture of the cranes in the air. What tells you they’re
landing, not taking off? (See How
Birds Fly -- A Journey North In-Depth Lesson)
“Here
the trio of adults (#105, #204 and #218) are threatening the costume
(Dan Sprague) when he enters the pen.” |
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Journaling
Question:
“What body language tells you the cranes are threatening the costume?”
(See Dominant or Submissive?
Leader or Follower?)
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Unison
Call. Sara Zimorski. |
Who’s
Doing the Duet? Challenge Question #3
Sara says, “This picture is #105 and #218 unison calling in the
pen with some of the 2003 chicks around. One of the other adults is also
calling in the back of the picture on the right, but I don't know which
one she is.”
The unison call is made by pair-bonded cranes and often
used in the elaborate courtship dance rituals. As Heather Ray describes
it, "The male throws his head waaaaay back (ouch) with beak pointing
straight up and make a continuous 'Whoooop,' and in response the female
will flick her head almost in a pumping action, giving two shorter 'Whoops'
for every one of his."
(To respond to this question, please follow the instructions
below.)
Tom Stehn Reports:
The Low Point
After Tom’s last report, we know that the tallest bird in North
America has something special to "whoop" about: the highest
numbers of endangered whooping cranes wintering in Texas in approximately
the last 100 years. This week’s letter is more serious:
Dear Journey
North,
“In my last report, I was glowing with news of the remarkable
year that the whooping cranes had. Now I want to mention the low point
of the year.
“An adult whooping crane was shot and killed November 14th, 2003
south of Dallas, Texas. Four whooping cranes had been present for several
days feeding in a cornfield during the day and presumably roosting at
night on a nearby reservoir. One crane was shot about 15 minutes before
sunset, apparently as it flew to roost. Locals heard shots, and with
the waterfowl season closed, the local game warden was called. A Texas
Parks and Wildlife warden responded and apprehended the hunter with
3 ducks plus 1 whooping crane hidden in a bag tucked under the bow of
his boat. The hunter admitted he had shot a white crane. The necropsy
showed the bird to be an adult female whooping crane with about 20 shot
pellets in her. The 3 remaining cranes resumed migration 2 days after
the shooting incident.”
How did the
suspect plead? When is his sentencing? What are the possible sentences
for this crime? How many other endangered whooping cranes have been shot
in North America? What helpful solutions does Tom recommend to prevent
any more whooping crane shootings? You’ll find the answers here:
Crane
Population Dynamics: Let Me Count the Ways
Click
graph to enlarge
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Tom’s
news is one reminder of how crane numbers change from year to year. "Population
Dynamics" is the study of changes in the number and composition of
individuals in a population, and the factors that influence those changes.
Scientists who study population sizes and the many variables that affect
them have a challenging task. You'll appreciate those challenges by thinking
through this problem yourself! On the chart below (see link), list all the
factors you discover that can cause high or low numbers at each stage of
the whooping crane’s annual cycle. Keep and maintain this chart during
your crane study. How many variables can you add over time?
PTTs:
Discussion of Challenge Question #1
Challenge Question #1 asked you to meet the flock and find out this: "Which
birds from the 2003 ultralight migration are now wearing satellite transmitters
(PTTs)? Why do you think these birds were picked?" Hooray for Mansi,
Jessica, Catlin, Nick, and George from Iselin (NJ) Middle School/grade
7. They sent this answer:
“The birds from the 2003 ultralight migration that are now wearing
satellite transmitters are: Cranes #301, 309 and 312. We think these were
picked because they exceed in independence, "good" following,
and are the stronger females of the entire group. With such characteristics,
they would be able to survive in various conditions and they will always
be on the right track of their migration.”
Detectives
Digging Deeper: Challenge Question #4
The Iselin students carefully considered each crane’s biographical
notes. There’s another BIG consideration that went into the choice
of these three birds. You’ve hear that history often repeats itself.
We’d like to send you back for another look at the history of ALL
ultralight-led cranes to see if you can dig deeper:
Challenge Question #4:
“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?”
(To respond to this question, please follow the instructions
below.)
Unison
Calls: Discussion of Challenge Question #2
Last time we asked, "Why have the 3 near-adult cranes in the Florida
pen site been doing more unison calling since latecomer #214 showed up?"
(Before you read the answers, remember that ALL the cranes are still too
young to pair up for breeding, and too young to lay eggs and raise chicks.
Also, they are on their wintering grounds, and not on their breeding grounds.)
Here’s what we heard from these good thinkers at Iselin
Middle School/Grade 7:
Alex, Sabrina, Frank, and Cheyenne correctly answered:
“They thought crane #214 was an intruder.”
Anita, Ritesh, Nina, and Robert wrote, “The 3-near-adult
cranes in the pen site have been doing more unison calling since latecomer
#214 showed up because they don't accept #214. They are showing #214 that
she can't be part of their group.”
Jessica, Mansi, Nick, Caitlin added, “The 3-near-adult cranes in
the pen site have been doing more unison calling since late comer #214
showed up because these three birds are territorial and dislike the new
invader in their territory.”
These readers also had the right idea:
AA Townsend: “The 3 near-adult birds are probably
whooping at #214 to assert dominance and claim territory.”
Justin: “They might be trying to figure out who
she is and trying to see whether or not she can join into their pen!”
Nice work, all of you! Operation
Migration’s Heather Ray confirms what you said: “I believe
the trio of cranes #105, 204 & 218 have been doing more unison calling
since the arrival of #214 as they recognize her as an outsider, or a potential
challenger to the territory they feel they have established at the pen
site. She is obviously another sub-adult and doesn't look like the juveniles,
so she’s likely being viewed as a threat to their territory.”
Anticipating
the Migration: Video Clip and Lesson
Operation Migration’s Heather Ray reminds us: “Last spring
brought a telephone call on April 1 telling us that the 2002 cranes had
departed their winter pen and were being monitored by the ICF tracking
team as they headed north. With only 3 weeks left until April, we, probably
just like many of you, are left to impatiently wait, and wonder just when
the Class of '03 will fly away home.”
Next week we’ll talk more about satellite tracking and the PTTs.
Until then, enjoy this slow-motion video clip of the 2003 cranes flying
last fall with the ultralight. The video (see Web) gives you an up-close
look at flying cranes in slow motion. It starts with 3 birds and the ultralight,
very close. You see more birds later. You'll get a good look at the primary
feathers and the birds' flight posture as they flap and soar. Notice
the slow downward stroke of the wingbeat, followed by a quick upward motion.
Do you wish you were in the air with them? How do birds manage to fly?
How are their bodies adapted for flying? How do their wings work? What
two flying techniques keep them in the air? How is a crane's flight different
from other birds? You'll find all those answers and more in our in-depth
flight lesson:
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 #3 (OR #4).
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 March 26, 2004.
Copyright 2004 Journey
North. All Rights Reserved.
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