Bald Eagle Migration Update: April 14, 2004

Today's Report Includes:

Latest News and Migration Map
Eagleye Nye has flown the coop – vacationing with his family – but before he left he sent the latest news and data for us to examine.

Field Notes from Peter Nye

Hello All,
Just time for a quick update before I leave for our spring vacation.
Looks like the big news is.....V98 is not a NY nester! She's clearly "on her way", and it looks like she departed perhaps between 11 am and 2 pm on 5 April. I've included some extra data fixes for that date.
We had strong winds here on the 5th; might have had something to do
with it.

A20 continues to move north also, while A00 is content where he is.

Regards, until next week.

Eagleye
Endangered Species Unit
Wildlife Diversity Group
Endangered Species Unit
Delmar, NY

Reading Between the Data Points
Pete Nye thinks that our new Bald eagle V98 is “on her way.” How does he come to this conclusion? A glance at the data doesn’t show much change. Our mapmaker, Daphne was also curious about Eagleye’s observation, “I labeled two of the new data points individually instead of in that clump in case that little bit of movement means something!”

What do you think? Here are the dates and the locations:

 Date Latitude Longitude 3/15 44.09 -74.34 3/17 44.12 -74.25 3/19 44.10 -74.29 3/21 44.11 -74.36 3/23 44.07 -74.34 3/25 44.09 -74.36 3/28 44.11 -74.32 3/30 44.11 -74.33 4/01 44.09 -74.32 4/03 44.07 -74.34 4/05 44.19 -74.30 4/05 44.11 -74.20 4/05 44.09 -74.40

Study the data giving particular attention to the 3 signals recorded on 4/05 (a windy day).

Challenge Question #22:
“Looking at the transmitted data from her locations 3/15 – 4/05 do you notice any thing different about V98’s locations on 4/05 that would lead you to believe she is “on her way? Do you agree with Eagleye?”

(To respond to this question, please follow the instructions below.)

Comparisons Between Golden and Bald Eagles
While Bald Eagles are found only in North America, Golden Eagles live in Europe, Asia, north Africa, and North America. And, while Bald Eagles are usually found near water, Golden Eagles can be found in very arid areas where there is no water for miles!

Bald Eagles belong to a group called "fishing eagles." Golden Eagles are not closely related to Bald Eagles, they are more closely related to hawks called "buteos," a group which includes the Red-tailed Hawk. But Golden Eagles look a lot like immature Bald Eagles, from their huge size and 80-inch wingspan to their dark plumage. Golden Eagles have feet adapted to catching their prey on the ground. Their legs are well-feathered, unlike the legs of Bald Eagles.

Challenge Question #23
"Why do you think Bald Eagles feather-less legs?" What adaptive advantage do naked legs have for Bald Eagles?"

(To respond to this question, please follow the instructions below.)

 Is this an eagle skeleton? Defend your answer.
Eagle Migration: A Flight Lesson
Eagles have very long, large wings. It takes a lot of energy to flap such large wings. That is why when eagles are flying long distances, especially on migration, they often soar on thermals until they reach a great altitude, and then use the gliding/soaring method of flying to cover the longest distance using the smallest amount of energy.

How Birds Fly: An In-Depth Primer About Flight
Enjoy this primer about bird flight. Learn about "lift" and airfoils--then try these activities:

Try This!
To see how an airfoil works, hold a narrow strip of paper near your mouth and blow across the top. The air moves faster above than below, and the paper will rise. Does this work with a larger piece of paper? Why or why not?
Design and build an eagle kite using our eagle silhouette design, or create your own. Go outside and fly it.

When Will They Hatch? Discussion of CQ #20
Eagles Online has a Web camera poised over a Bald eagle nest in MA. The nest contains 2 eggs laid on March 8, and 11. We asked you, “When do you predict each of the eggs in the Eagles Online Webcam nest will hatch?”

Fifth Grader, Monique from Ferrisburgh Central School predicted the eggs will hatch around April 14. That’s TODAY! Thanks also to Seventh Graders at Iselin Middle School for their prediction - !

How do YOU figure the dates? Here is one way:

Egg #1 Laid on March 8
1. Since March has 31 days 31-8=23 days. This is how many days in March the egg was in the nest.
2. 35 total days incubation – 23 days already incubated in March, so there are 12 days needed in April until the egg will hatch.
3. That makes it April 12 for Egg #1

Egg #2 Laid on March 11
1. Since March has 31 days 31-11=20 days. This is how many days in March the egg was in the nest.
2. 35 total days incubation needed – 20 days already incubated in March, so there are 15 days needed in April until the egg will hatch.
3. That makes it April 15 for Egg #2

Keep an eye on the Webcam and maybe you can witness this historic event in the life cycle of one of our most magnificent North American birds!

How Much do Satellite Transmitters Weigh? Discussion CQ #21
“If you wore a backpack that weighed 2% of your body weight, how heavy would your backpack be?”

Three third graders from Ferrisburgh Central School weigh between 50 and 90 pounds. Here is what they calculated: Their backpack would weigh between 1 and 1.8 pounds.
What weighs this much?

• Ashley figured that would be the same as having her Bratz doll strapped on her back. That wouldn't slow her up at all.
• Charlie could have 3 Playstation game cartridges on his back. He thinks he would get used to that.
• Kristian could have the Chewbacca Star wars Action figure on his back. He knows that wouldn't slow him up at all.

Ashley, Charlie and Kristian all think that the eagles get used to the weight and don't notice it at all.

Seventh Graders weigh more. At Iselin Middle School, Danielle, Robert M, Chris C, Moaz, Tom, Heather, Kristina and Caitlin weighed in for this problem. Ranging in weight from 79 to 125 lbs, their backpacks would need to weigh between 1.58 and 2.5 lbs.

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-eagle@learner.org
2. In the Subject Line of your message write: Challenge Question #22 (or #23).
3. In the body of EACH message, answer ONE of the questions above.

The Next Bald Eagle Migration Update Will Be Posted on April 21, 2004.