Bald Eagle Migration Update: February 5, 2003

Today's Report Includes:

• Welcome Back to Bald Eagle Biologist Peter Nye
• Field Notes from Peter Nye
• Looking Back at Fall Migration
• Counting All Eagles: Mid-winter Bald Eagle Survey
• Why Count Manatees, Monarchs and Eagles in the Winter?
• Challenge Question #1
• Do All Eagles Migrate?
• The Big Question: Why Migrate? Challenge Question #2
• Tips for Teachers: Are YOU Ready for the Migration?

• About Biologist Peter Nye
• Peter Nye's Research Goals

Dear Students,
Hello to all returning and new eagle trackers! This is Peter Nye from the New York State Department of Environmental Conservation. I'm back and ready to share our satellite-tracking work with bald eagles here in New York State with you.

• High, High Tech: The Science of Satellite Tracking

Eagle with satellite backpack.

We already have 5 eagles "on-line" for you to help us follow. Four are last year's bald eagles (two adult females and adult two males) who have now completed their round trip migration. In addition, we are tracking an immature golden eagle that was captured last March. We hope to deploy at least one or two new satellite transmitters this winter, on either bald or golden eagles, so stay tuned!

Fall 2001	Fall 2002

Looking Back at Fall Migration
It is always interesting to compare the year to year migrations of our previously tracked eagles, in terms of movement paths and timing.Here are the fall migration maps for 2001 and 2002. Use the chart below to record and compare when the eagles began migration each fall, the routes they traveled, and how many days the trips took.

• Comparing Fall Migrations: 2001 & 2002

Counting All Eagles: Mid-winter Bald Eagle Survey

We conducted our mid-winter survey in New York on January 7. My helicopter portion in southeast NY counted 234 eagles. This is amazing! Especially when you consider that when I started doing these surveys in 1978 the eagle counts were only in the 20’s! Noteworthy was the number of immature eagles this year: Of the 234 eagles counted, 90 were adults and 144 were immatures. This is a record, and good indication of healthy production. Interested students can read more about the U.S. National Bald Eagle Mid-winter Survey on the web.

It should be another exciting and busy winter. Thanks for joining us!

Eagleye Nye

Peter E. Nye
New York State Dept. Environmental Conservation
Delmar, NY

Peter Nye with a juvenile and adult eagle The full white head and tail of the adult (photo at right) don't appear until eagles are 5-6 years old.
Juvenile Eagle	Adult Eagle

Why Count Manatees, Monarchs and Eagles in the Winter?

Journey North works with scientists who study the migrations of all kinds of creatures. As happens every year, this January biologists surveyed the populations of Florida's manatees, Mexico's monarchs and the United States' bald eagles.

Challenge Question #1
"Explain why you think January is the best time to count manatees, monarchs and bald eagles. (Clue: The annual surveys take place in January for all of these species for the same reason.)"

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

However, the individual eagles we are tracking with Peter Nye do follow the conventional migration pattern. As you can see on the fall migration map above, they nest in Canada and migrate south for the winter. Other bald eagles--including some in New York--don't migrate at all. These are called "resident" eagles.

So you can see that, within a single species, there is variation. The behavior of all individual eagles is not the same. All species have variation among individuals, and this is one of the great challenges scientists face when studying a species. Keep individual variation in mind as you track Peter Nye's four eagles. Be careful whenever you generalize based on a small sample size.

Challenge Question #2
"If eagles migrate south for the winter, why do they bother to go back north? Why don't they just stay in the south?"

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

Latitude, Longitude and Distance Traveled
This lesson will help you get comfortable with satellite data, so you'll have a feeling for the distances involved when an eagle's latitude and longitude readings change.

How to Map Satellite Telemetry Data
This lesson includes charts with step-by-step instructions for pinpointing an eagle's latitude and longitude on a map. By putting a transparency on top of your map, an eagle's exact location can be more easily found.

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 #1 (or #2).
3. In the body of EACH message, answer ONE of the questions above.

The Next Bald Eagle Migration Update Will Be Posted on February 12, 2003