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Manatee Migration Update: February 17, 1999

Today's Report Includes:

The Secret's Out About Dmitra and Ivan!

"We think they're travelling in the same family, same pod or they're mates", said Scott Young P.S. fifth graders Steph, Emily and Sarah from Ontario, in their answer to Challenge Question #2 about comparing the satellite data for Dmitra and Ivan (Kevin.Adams-SYPS@fc.vcbe.edu.on.ca).

Dmitra and Ivan are definitely in the same family--in fact, they're a cow and calf! According to scientist Cathy Beck, Dmitra is a small mom, 281 cm. and Ivan is a big male calf--209 cm now. Sirenia scientists first met them in Feb 1998, wintering in the warm spring waters of Crystal River. Ivan was probably born in the summer of 1997.

Keep a close watch on Dmitra and Ivan's movements. Cathy Beck says that "as the weather warms, we'll anxiously watch where these manatees travel, and how long they remain together."

When Do Manatees Leave Their Mothers?
Latest Migration Map
(Click on map to enlarge)
Cathy and her fellow Sirenia Project scientists have provided the latest satellite tracking data. Plot the locations on your map and take a look at the map that we have prepared.

Today's Satellite Migration Data
(Courtesy of U.S. Geological Survey's Sirenia Project)

As a class, discuss what changes you see in the manatees' locations since the last report. Then, take a closer look at the latest data for Dmitra and Ivan and try to answer:

Challenge Question #3
"Using the Feb. 5 longitude readings for Dmitra and Ivan, can you figure out how far apart they were on that day? Can you tell from this whether Dmitra and Ivan are still together?"

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

Why Knicky Moved--Discussion of Challenge Question #1

Knicky

Photo: U. S. Geological Survey, BRD, Sirenia Project

In the last report, we asked you to describe why Knicky moved when and where she did. The fifth grade students at Scott Young P.S. in Omemee, Ontario "wandered" right along with Knicky on this question and correctly discovered that cold temperatures were a key factor:

"Knicky started off the coast of Tybee Island on November 23, 98. Then Knicky travelled south...and stayed in the Titusville area because the water is warmer." Steph, Emily, Sarah, Scott Young P.S. Fifth Grade, Omemee, Ontario (Kevin.Adams-SYPS@fc.vcbe.edu.on.ca)

As Cathy Beck explains, manatees seek out warmth in winter because they "are susceptible to cold-related disease, and in the winter they gather near warm water sources such as natural springs or warm water effluents of power plants." When Knicky began moving south in early January, Cathy wrote that "We did get temperatures in the low 20's earlier this week. Knicky is our wanderer that summers at Hilton Head, SC and Georgia. She finally moved south with this last cold front and is currently in Brevard County."

December 29

December 31

January 6

Maps: Unisys Weather.

Take a look at these satellite weather images. Can you see how the falling temperatures correlate with Knicky's movements south? As you consider the falling temperatures, try to answer this:

Challenge Question #4:
"Why do you think a large marine mammal like a Manatee cannot tolerate cold water when another large marine mammal like a Whale can?"

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

Hot Spot for Manatees

Ranger Wayne Hartley

Here's the first news of the season from one of the manatees' favorite Florida hangouts: "What a season! I think I have a record total number of 110 manatees and 10 calves, and they set a record for late arrival too, 15 December 1998!", writes Ranger Wayne Hartley of Blue Spring State Park, located inland at Orange City, Florida. Each winter many manatees swim from the St. John's River into the "Run" at Blue Spring, which is like a creek that "runs" for 1/3 mile from the park into the River.

We are lucky to have Ranger Wayne providing us with this unique manatee data for the third year in a row. Each day, Ranger Wayne canoes into the Run to conduct his manatee "Roll Call." He identifies each individual manatee and counts the total, measures water temperatures in the "Run" and the river, and the high and low air temperatures too.

To learn more about "Deep Dent", "Georgia", "Peaches" and Ranger Wayne's other visitors at Blue Spring this season, go to:

A sample of Ranger Wayne's Blue Spring data for this season is below. Discuss the changes that you see from one date to another, and then see if you can answer this:

Date

Air Temp High(C)

Air
Temp
Low(C)

River Temp (C)

Run Temp. (C)

# of Manatees

12/15

16.5

10.5

21.6

22.5

5

12/25

31

17

22.3

nt

0

12/30

25

9

19

22.6

34

1/5

17

1.5

17.2

nt

81

1/11

28

2.5

14

22.4

73

1/15

30

17.5

15.5

nt

33

Challenge Question #5:
"Can you see a pattern or trend in Ranger Wayne's data that might explain the changing number of Manatees counted at Blue Spring each day?"

How to Respond to Today's Challenge Questions

Please answer ONLY ONE question in each e-mail message!:

1. Address an E-mail message to: jn-challenge-manatee@learner.org
2. IMPORTANT: In the Subject Line of your message write: Challenge Question #3 (OR #4, OR #5 )
3. In the body of the EACH message, give your answer to ONE of the questions above.


The Next Manatee Migration Update will Be Posted on March 3, 1999.

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