Journey North News

Peregrine Falcon Migration Update:
April 29, 1996

We have great migration news to report this week! Once again, biologist Skip Ambrose managed to captured a glimpse of peregrine migration even though his satellite readings only come once every 20 days. This time the news is from Falcon # 655, one of the hatch year (HY) birds from the Alaska population. It is particularly exciting whenever we hear from these HY birds. Here's why:

• Mortality is extremely high in young birds. Ambrose estimates that roughly 65% die during the first year!
• Nobody knows where peregrines spend their first summer. Information from these birds gives Ambrose a chance to find out--and accomplish one of his primary research goals.
• Migration is still very new to these young birds; they are taking the trip for only the second time in their lives. When we compare the migration of young birds to that of adults we gain insight into one of the big questions about the biology of migration: "How much knowledge about migration is learned and how much is innate?" The date of departure and the rate of travel are clues that can help answer this question.

The colorful map above shows the FALL migration route of all six Alaska falcons. Look at the route Falcon # 655 took last fall. It is shown in light green. Would you expect the birds to follow the same route in the spring and fall? How closely? Find the answer for Falcon #655 using the data below from April 23rd.

Background
On April 4th, readings from this falcon were still coming from the wintering grounds in Chiapas, Mexico (17.917 N, 92.203 W). In our April 15th report we asked, "Where do you think this falcon will be when we hear from it next? Back in Alaska? Wandering around the continent? Or will the readings continue to come from the tropics?" Students at Blake School reminded us that continued readings from the tropics could also mean the falcon had died or the transmitter had fallen off.

A Day in the Life
Data from a single day answers these concerns. As you'll see in reviewing today's data, on April 23rd three satellite readings were received. This information raises a whole list of new questions--as well as today's Challenge Question which you'll find below. As a class, discuss these things:

• Do you think Falcon # 655 will stay where she was on April 23rd or move on?

• Where do you think this falcon will be in 20 days when the satellite sends the next signal? Predict the latitude and longitude of its next location.

• In which direction was the falcon travelling on April 23rd?

• How far did she travel in the 7 1/2 hours between satellite readings?

• If she was flying the entire time, how many miles per hour was she moving?

• What time of day was this falcon migrating? Why do you think she might travel at this time of day? (Note: The time given is "Zulu" which is the same as Greenwich Mean Time. To translate to local time, subtract 7 hours because the bird is 7 time zones to the west of Greenwich. )

Challenge Question # 101
"Where was Falcon #655 at 1:28 on April 23rd? (Name the nearest town as well as the state, province and country it was in.)" "What time of day was it (local time)?"

To respond to this Challenge Question, please follow the instructions at the end of this report.

Recommendation:
To map today's data simply, we suggest placing a transparency on top of your map. You will then be able to mark off latitude and longitude lines in a grid and pinpoint the locations exactly.

APRIL 23, 1996
Falcon # 655 (Age=HY) (From the Yukon)

Time.......Latitude/Longitude
1:28.......32.115 N, 105.506 W
3:04.......32.311 N, 105.704 W
8:55.......32.361 N, 105.749 W

DATA SUMMARY
Falcon # 655 (Age=HY) (From the Yukon)
Date..............Location
11/18/95..........17.758 N, 92.145 W
12/08/95..........17.816.N, 92.312 W
01/16/96..........17.873 N, 92.616 W
02/05/96..........No Data
02/25/96..........17.842 N, 92.450 W
03/15/96..........17.794 N, 92.450 W
04/04/96..........17.917 N, 92.203 W
04/23/96..........32.361 N, 105.749 W

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Thanks to students in Alaska and New York for answering Challenge Question # 94 "How many miles did Falcon # 867 move in the 4 hours between satellite readings?" These estimates are very hard to make and the students' work is very good considering the level of difficulty! We hope the suggestion above will help you in the future.

From ALASKA:
Falcon #867 moved 100 miles in the 4 hours between satellite readings.
W. Mike Sterling (sterling@corcomsv.corcom.com)

From NEW YORK:
We think Falcon #867 flew about 50 miles.
Ms. Babcock's Tuesday group, grade 4
Elmont, New York
k12elbac@vaxc.hofstra.edu

From Skip Ambrose:
"It looks like she moved about 30 miles in that 4 hour block, so she probably was not flying constantly during that 4 hours."

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Thanks also to Rod Murray of Ontario for this news:

A pair of peregrine falcons are nesting in downtown Toronto, Ontario, Canada and they can be seen with the Falcon Cam every 2 hours! Be prepared to watch the eggs hatch! To see some Peregrine falcons live point your browser to: Rod Murray

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How to Respond to Challenge Question # 101:

1. Address an e-mail message to: jn-challenge@learner.org
2. In the Subject Line write: Challenge Question #101.
3. In the body of the message, answer these questions:

"Where was Falcon #655 at 1:28 on April 23rd? (Name the nearest town as well as the state, province and country it was in.)" "What time of day was it, local time?"

The Next Peregrine Falcon Migration Update Will be Posted on May 6, 1996.

© Journey North 1996