Journey North Bald Eagle Spring 2004

Bald Eagle

Bald Eagle Migration Update: May 5, 2004

Today's Report Includes:

Latest News and Migration Map
Field Notes from Peter Nye
Shoulders, Wrists and Elbows
Big Foot
How are they Changing? Observations for CQ #25
Eagles are Big Babies: Challenge Question #26
Fresh Fish Deliveries Also Attract Flies
Home Again, Home Again (When will Eggs Hatch in Canada?)
Year-end Evaluation: Please Share Your Thoughts

Latest News and Migration Map

Not much movement to report, as expected, with the exception of golden A20, who seems to be moving east and west trying to make up his mind!

Field Notes from Peter Nye
No field notes from Peter Nye this week. He is off in the field taking surveys again. Since nesting activity is underway in Bald Eagle habitat everywhere, we can focus on nesting phenology this week.

Shoulders, Wrists and Elbows

Eagles' wings look scrawny without the flight feathers.

Look at how this eaglet is growing, and how gangly it looks now! The bones and muscles of the wings grow before the flight feathers come in, and the wings look strangely scrawny. At this point, you can see how the eaglet's wing bones correspond to your arm bones.

Can you find the shoulders, wrists and elbows? (Hold your arms in the same position to your body, to help you visualize.) Once the feathers grow in, it's much more difficult to see the structure of the wing bones, as you can tell by comparing the young eagle to its parent. The adult’s wing bones are identical, but are buried under flight feathers.

Click to see larger picture of eaglet's feet.

Big Foot

Look at this baby's big, strong feet.

The feet on eaglets must grow strong and sturdy very quickly after hatching, because it's critical that the baby be able to hang on tight in powerful winds, and when the baby goes to the edge of the nest to poop.

How are they Changing? Observations for CQ #25
It is a lucky thing for eagle lovers to be able to watch the eagles in Massachusetts grow and develop in the nest. How have they changed since hatching out 3 weeks ago? Here are some of the things you noticed:

Observations in the Eagle Nest

3 Weeks Old and Counting
How have the little Eagles Online chicks grown during their lifetime? Let’s look again. What do you notice now?

Photos Courtesy of Eagles Online

4/14/2004 - 1 Day Old	4/21/2004 - 7 Days Old	5/04/2004 - 20 Days Old

Eagles are Big Babies

Eagles remain in the nest for 10-12 weeks before they fledge. And they are not good at catching fish when they first leave the nest. They pick up dead fish along shorelines first, and then progress to picking up dead fish floating in rivers and lakes. It may take months for an eagle to start catching its own live fish, and much longer for it to become reliable at fishing. This means that young birds must spend more time fishing to catch the same number of fish as adults. All in all, the first years of a Bald Eagle's life are a time of enormous learning and exploring the world around them.

Challenge Question #26:
“A baby robin fledges when it's only 13 days old, and a hummingbird at 21 days. If an eagle fledges when its 10-12 weeks old, how many days is that? Why do you suppose young eagles take so long to grow up compared to hummingbirds and robins?””

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

Fresh Fish Deliveries Also Attract Flies
Pet Nye shares his observations:

Adult eagles obviously bring in a lot of fish for the 3 months their young are in the nest, and that can be quite an attraction to flies and other insects! It can also create quite a smell! Occasionally, insect loads are so bad up in a nest, that a chick or two may die, due to stress and simply being bitten to death; I've seen this with black flies in our Adirondack region where bugs and insects are intense. (I would imagine many parts of interior Canada are the same.) Eagles might get some relief from this, by putting their nests up very high, and thus keeping up and away from insects as well as benefiting from more regular breezes, which act to keep bugs down.

To help keep nests clean, eagles continuously add fresh vegetation to their nest, covering up old food. I have yet to see them actually "clean-up" their nest, however, by removing old fish scraps. Some nests get pretty gross with old, maggot-filled fish parts stuck in the sticks of the nest, baking in the hot sun! Eagles often build "alternate" nests, within their territory near their other nest, likely in an attempt to let one nest sit unused for a year or two, to allow it to "weather" and clean itself out.

Home Again, Home Again (When will Eggs Hatch in Canada?)
What are our eagles busy doing from their locations in Canada? Eagles usually don't lay eggs until several weeks after arriving at the nest site. They spend the first days dealing with their neighbors, if any, and performing their courtship rituals. The spring is filled with the tasks involved with bringing up a family – and producing the next generation of eagles.

Since we have no nest cameras focusing on the eagles in Canada we have to rely on what we know of eagle nesting phenology. Last week you learned about the critical steps involved with producing an eagle family. We have also been watching the Bald eagles raise 2 eaglets via the Eagles Online web camera.

Now put yourselves to the task of predicting what is going on in our eagles’ nests in Canada! Use the eagle maps and data to calculate when the birds arrived in their nesting area. Then calculate what is, or will be happening by reviewing the phenology information on the chart provided.

Use this chart and the Nesting Phenology information:

Year-end Evaluation: Please Share Your Thoughts!
Please take a few minutes to share your suggestions and comments in our Year-End Evaluation Form below.

In the coming year, Journey North will be fundraising to secure increased support from foundations, corporations and individuals. Your supportive comments will be a tremendous help. Thank you!

Journey North
Year End Evaluation

Please share your thoughts

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 #26.
3. In the body of EACH message, answer ONE of the questions above.

The Final Bald Eagle Migration Update Will Be Posted on May 12, 2004.