This is the second set of satellite data from the peregrine falcons that were tagged in Alaska last summer by Skip Ambrose. Hopefully you didn't draw too many conclusions based on the single report you received. After all, the first set told you just one thing: The location of each bird in late December or early January.
This second set of data can help you begin to answer one of the most important questions of Skip Ambrose's research. That is, "What is the peregrine falcon's 'home range' on its wintering grounds?" As you look at the data below ask yourself these questions:
1) Have the birds moved since the last readings or stayed in the same place?
2) Which bird moved the greatest distance? Which has moved the least?
3) Do you think peregrine falcons have small territories during the winter or are constantly "on the move"?
4) Why is it so important to know the "home range" of a species?
In the weeks before the peregrines begin to migrate, map the home range of each bird.
5) Do you think all 7 birds will behave in the same way?
6) How do their home ranges compare in size?
Falcon Date Latitude Longitude 22652 1/20/95 35.761 S 60.328 W 22653 NO REPORT 22654 NO REPORT 22656 1/30/95 18.763 N 95.138 W 22657 1/19/95 64.958 N 141.216 W 22658 1/20/95 10.111 S 42.260 W 22660 1/23/95 18.621 N 95.584 W 22663 1/29/95 10.328 N 84.309 W
Notice that we didn't receive reports from two birds. Next week Skip Ambrose will comment on this observation. Make a list of possible explanations and see if you can guess the reason(s) correctly.
Just a Minute!! Have you noticed that the latitude and longitude figures provided above use different minutes than are shown on most maps? Maps show minutes in 60ths whereas the minutes in the satellite data are given in 1000ths. In order to plot locations on a map you must translate the minutes from 1000ths to 60ths. Try to figure out how to do this before you look at the examples in the HELP SECTION below.
CHALLENGE QUESTION There's a new report this week from a bird we haven't heard from before.
Which number is new and how do you interpret the reading?
Send your answer to: jnorth@informns.k12.mn.us (NOTICE: Spelling counts. Computers insist that you address your mail VERY carefully. Many people have overlooked the "n" in the "informns" portion of our address. )
HELP SECTION How to Translate Minutes from 1000ths to 60ths:
Example 1 Using the latitude reading of 18.596 N from bird # 656 on January 30th: A full degree would be 1000 minutes. This reading is 596 of 1000, or 59.6 % of a minute. On a map, a full degree is 60 minutes. 59.6% of a 60 degree minute is 35.76. Therefore, the latitude would be 18 degrees, 35.76 minutes.
Example 2 Using the longitude reading of 84.309 W from bird # 663 on January 29th: A full degree would be 1000 minutes. This reading is 309 of 1000 or 30.9% of a minute. On a map, a full degree is 60 minutes. 30.9% of a 60 degree minute is 18.54. Thus, the longitude would be 84 degrees, 18.54 minutes.
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