Whooping
Crane Migration Update: April 8, 2005
Today's Report Includes:
- All Chicks But One Are Back in Wisconsin!
- Fly by Night? Challenge Question #8
- Western Flock on the Move: Challenge Question #9
- Try This! Log the Main Flock’s Spring Departure
- Whoopers Are Weather Wise
- Western Cranes: Confirmed Sightings in the Central Flyway!
- Signals From the Sky: About Those PTTs
- How Cranes Fly: Links to Lessons
- Dancing With the Cranes: Video Clip, Story, and Teacher Tip
- Crane Speed: Answer to Challenge Question #5
- Four Differences: Discussion of Challenge Question #6
- A New Average: Response to Challenge Question #7
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Today's Migration Data |
All Chicks But One are Back in Wisconsin!
Whoopee! All 12 of the migrating hatch year 2004 chicks have returned
to Wisconsin in the past few days! They haven’t yet shown up
at Necedah NWR, but any day should bring that joyous news. One chick,
#418, is the ONLY crane in the entire Eastern flock not migrating.
He is still on the Florida wintering grounds. Young #418 found his
way to Florida last fall after being left in Wisconsin due to feather
problems when his flock mates left with the ultralight. When will #418
leave Florida? Will he find his way back? We’ll keep you updated
as we find out! You can see their progress on the map, and get more
details on this historic migration here:
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Migrating
cranes #105, #204 and #412 on March 30 in Thomas County, GA |
How are the "experienced" members of the flock doing? Fifteen older ultra-cranes are also home in Wisconsin: 101, 202, 209, 203, 218, 205, 211, 212, 217, 303, 312, 316, 317, 102 and 208. We’ve had no further reports for either #107 (last reported at Horicon NWR in Wisconsin on March 14) or #106 (last reported at Hiwassee State Wildlife Refuge, Meigs Co., TN on March 7). Cranes (#301, 309, 318), who spent the winter in North Carolina, were seen Wednesday in western New York, just across the Pennsylvania border! They apparently followed the Lake Michigan lakeshore NE. Where will they end up? Stay tuned, and check their flock charts:
Journaling Questions:
- Why were the 2004 chicks able to make their journey north so much swifter than their journey south?
- Why are the project leaders and trackers working so hard to keep track of each crane in the Eastern flock?
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Who
are these HY2004 chicks? (See Banding
Codes to find out.) Note the red
patch forming on top of their heads. |
Fly by Night? Challenge Question #8
Whooping Cranes are normally reluctant to fly at night. But on April 3 Group 2 flew nearly 13 hours with the final 3 hours in darkness! Given #412’s history, Journey North Whooping Crane Expert Laura Erickson wasn't very surprised; she remembered Nov. 26, Day 48 of the bird’s journey south. Following the ultralight, one bird broke away as the flock left their stopover in Tennessee and crossed into Georgia. The runaway was chick #412. He ended up continuing south, past Atlanta, then north. Five people tracked runaway #412 for most of the day. They finally found him roosting only 8 miles from where the migration had departed from that same morning!
Whooping Cranes learn their migration route, and Laura
thinks that #412 must remember exactly what this
area looks like by night as well as day.
Laura is wondering about something else. Older ultra-cranes #105
and 204 stayed and flew with #412 all day AND even
in the dark.
Challenge Question #8:
“Older ultra-cranes #105 and 204 all stayed with #412 even in the dark as they flew over unfamiliar territory. What do you think this tells us about how whooping Cranes learn their migration route?”
(To respond to this question, please follow the instructions
below.)
Western Flock on the Move: Challenge Question #9
“The whooping crane migration is underway with an estimated 61 cranes having departed the wintering grounds at Aransas National Wildlife Refuge,” reports Tom Stehn from Texas. The excitement begins! Tom tells us that whooping cranes travel in small groups, often in groups of 5 or fewer. Single cranes sometimes even make the migration by themselves. Tom has this new challenge question for you; please send us your answers!
Challenge Question #9
“What advantages can you list for the cranes to migrate at different times and not in large groups?”
(To respond to this question please follow the instructions
below.)
Imagine how tough it would be to count white cranes from
a small plane! Aransas NWR consists of over 70,000
acres that
attract
thousands fo
migratory birds. Tom sent us the flight report from
his 7-hour census flight on
April 6. How long does it take Tom and his pilot
to cover the 35-mile stretch of coastal Texas marsh that
the
whooping cranes occupy
during winter?
What percentage of whoopers have departed? When does
Tom
expect the remaining cranes to leave on migration?
What kind of weather
are
they waiting for?
Find all these answers and more in Tom’s latest field
notes:
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. In other words, 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. They’ve flown this route for centuries. Be scientists and keep track of the flock’s spring departures with Tom’s census reports, coming weekly in April, and a Log Sheet to download and print:
Whoopers Are Weather Wise
Tom reminds us, “In a typical year, most adult pairs don't leave for Canada until the second week in April, give or take a few days. However, last spring the migration was on the early side; nearly one-third of the flock gone from Aransas by April 2.” What are they waiting for?
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| April
6, 2005 .
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April
7, 2005. |
April 8, 2005. |
| With west winds blowing April 6 and 7, the cranes would stay put until the winds switch around to the southeast and provide tailwinds to aid the their trip north. | Do
weather forecasts look favorable on April 9 and 10 for migration? |
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Along Nebraska’s Platte River and the Central flyway, Martha Tacha is watching and sending us news. The weather is always a big factor in migration, as you’ll see in Martha’s field notes, next.
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Do you see 6 whooping cranes? Two are on the far right, on in front of the other. Photo Mindy Meade Vohland |
Western
Cranes in the Central Flyway!
Last time the only confirmed sighting
in the Central Flyway had been
a juvenile. Since March
28, the
bird was with
sandhill cranes
just
east of Grand Island, NE in the
Platte River valley. He was last
seen on
the morning of April 2-- rising
in a thermal
with sandhill cranes until out
of sight. With warm
weather and
south winds, Martha
Tacha is
sure he
headed north. “The majority of the sandhill cranes have gone. This
is believed to be the lone juvenile that wintered with sandhill cranes
in Matagorda County, 75 miles north of Aransas,” said Martha. That
bird was last seen in Texas on March 18, and "our" loner
was first observed in the Platte
River valley 10 days later.”
But more whoopers have arrived!
On April 6, Martha sent Tom Stehn
this
photo and
said, “Based on the photo
and last week's juvenile near
Grand Island, you'll be missing
at least 7 birds!” These
six adults were
first observed
April 5 on a rainwater basin
19 miles south and 2 miles west
of
Kearney,
Nebraska.
Weather was
rainy
and windy. They were
still present the
morning of April 7. North winds
in the area were forecast to
shift to
SW by afternoon,
so weather conditions for today
and tomorrow (April 8 and 9)
favor migration
with strong
(25-35
mph)
south winds and
mostly sunny skies. Go cranes!
Thanks to Martha C. Tacha of
the U.S. Fish and Wildlife
Service in Grand
Island, Nebraska for reporting
and sending the photo!
Signals From the Sky: About Those PTTs
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A
Platform Transmitter Terminal is
a satellite tracking device that can be worn/carried
by an animal so its position is known.
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Why
do you think the name and address of OM is on the
PTT?
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(Photos
Operation Migration)
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The
2004 journey north is the third year that satellite data
has ever been
available for whooping
cranes.
Prior to 2001,
whooping cranes had
not migrated over the
eastern portion of North America
in more than a century.
The trackers mainly rely on the radio signals
while tracking
(see April 1 report for
lesson link), but on April 6, it was
PTT data that
helped trackers figure
out where
the
group of
7 was after the birds
split off from the group
of 11.
How does the data come to us?
What are the limitations of PTT
data? What
do the units look like? Do the
leg units bother
the cranes? Explore the
subject here:
Try This!
Close your eyes. Imagine
being in your classroom,
day and
night, with
your eyes closed. Every
2 days, you blink your
eyes open
for a few
seconds. You ONLY have
that time to see what
is happening. The rest of
the time,
you see nothing but darkness.
As a class, consider
the conclusions you
might draw, based on
your limited observations.
Think
about that image
when you interpret satellite
data. The satellite only
sends a snapshot
representing a moment
in time.
What might be
happening when we're
not “looking?” What
might be some limitations
of satellite data?
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Photo OM, WCEP |
In the best migration conditions, cranes can use their large wings to soar on columns of warm rising air called thermals. Thermals are created as the sun warms the earth’s surface. Soaring on thermals allows cranes to stay aloft for longer periods of time without spending energy to keep flap their wings. Learn more about thermals, and how cranes fly with these fascinating lessons:
- Up, Up and Away:
Thermals and Updrafts
- How Birds
Fly: An In-Depth Lesson (with section on
cranes)
Dancing With the Cranes: Video Clip, Story, and Teacher Tip
It’s a rare thing to hear or see a whooping crane, but video clips make it possible. In this video by Heather Ray, a pair of whooping cranes shows you their dance. See the clip and find out three reasons why cranes dance. Then read the fascinating story of a whooping crane that would ONLY dance with a very special human--now a world-famous crane authority.
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Dancing
Cranes |
Teacher Tip:
Viewing Video
Clips as
a Scientist
Video clips
provide an
opportunity
for students
to make authentic
scientific
observations.
Here are
some
suggestions
for viewing
video clips
as a scientist:
Crane Speed: Answer to Challenge Question #5
Challenge
Question #5 asked: “On March 30, the group
of 11 flew for 11.5 hours. They covered 450 miles.
At what average speed (miles per hour) did the cranes
fly?”
Answer: 39.13 mph---crane speed!
Four Differences: Discussion of Challenge Question #6
Last time we asked you to read Tom Stehn’s full report and answer: “What are at least four differences between sandhill cranes and whooping cranes?”
Sandhills migrate at least two weeks earlier than whooping cranes. Sandhill cranes spend several days on the staging grounds along the Platte River in order to choose a mate, while whoopers don’t need the mass of cranes at a staging area in order to form pair bonds. Their migrations stopovers are brief, and they push north as soon as weather is favorable. Sandhills may change mates each nesting season, while whooping cranes generally mate for life. Sandhill cranes are smaller than whooping cranes, and gray-brown in color. Did you think of other differences as well?
A New Average: Response to Challenge Question #7
“ How many days was the 2004 flock on the wintering grounds before departing on their first journey north? Using this number, what is the average number of days on the wintering grounds in the 4-year history of the Eastern flock?”
Using the March 25 departure
date for the Eastern flock group of 11, and
their arrival date of the
previous December 12, we
calculated 104 days. Adding that number to
existing averages on the wintering
grounds 104, 126,
121, 117= 468) and dividing by 4, we get 117 days
for the
average stay on the wintering grounds.
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 #8 (OR #9).
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 15, 2005.
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1996-2005 Journey North. All Rights Reserved.
Please send all questions, comments, and suggestions to jn-help@learner.org
