Manatee Migration Update: April 14, 2004

Today's Report Includes:

• Field Notes-Two Big Changes and CQ #18
• Latest Migration Maps and Data
• Try This! How Big is Big Belvedere?
• More Manatee Adaptations: Skeleton, Flippers and Fat
• Saline and Skin-the Barnacle Connection
• A Lone Ranger (Wayne) at Blue Spring? CQ #19
• Manatee Math: CSI Lab Investigation: CQ #20

Since my last report, two important things have been 'changed' on two of the manatees. As you may remember, no ARGOS satellite signals had been received from Actual's tag for some time; and recently Belvedere's tag had not been functioning properly either. So my fellow Sirenia Project biologist, Jim Reid, actually removed and replaced Actual's and Belvedere's tracking tags. Here's the amazing part--Jim did this all without ever recapturing the manatees.

"Although Jim is a veteran tagging and tracking expert, this type of tag change procedure (called 'free tagging') can be difficult and dangerous. How do you think Jim went about doing this? Do you think you could do it? Just put yourself in his place, and remember how big manatees are! Actual is 298 cm in length and weighs 980 lbs.; and Belvedere is even bigger and heavier measuring 312 cm in length and 1,089 lbs. Do you think you could do the duty?

Challenge Question #18:
"If you had Jim's task to remove and replace Actual's and Belvedere's tags in the wild, how would you get close enough to them? How might they react? What suggestions would you give Jim about things to be careful of when tagging a manatee?"	Credit: USGS-Sirenia
(To respond to this question, please follow the instructions below.)

"When Jim removed Actual's original PTT/VHF tag, he replaced it with one of the new GPS tags. This will be an improvement in the tracking data we receive from Actual, since the GPS tracking tags can record more locations per day, and are usually very accurate too. See Satellite Tracking and Manatees

"As you can see from the latest Tracking Maps and Data, the manatees have not made any unexpected movements since the last report. For those of you following Actual and Giffer, they were still located near Cape Romano. And Belvedere remained in the north, while Leslie had just moved out of Turner River. There is still no news on Anna.

"I'll update you again soon."

Link to Latest Data and Individual Manatee Maps:
(Courtesy of U.S. Geological Survey's Sirenia Project)

• Data & Individual Map for Actual
• Data & Individual Map for Anna
• Data & Individual Map for Leslie
• Data & Individual Map for Belvedere
• Data & Individual Map for Giffer
• Data Only for All Manatees--Printer-friendly Format

Susan Butler
Sirenia Project

There's nothing like drawing an animal yourself to get the feel of its shape and features--try your hand at the Lesson: Manatee Art

• Why are Manatee flippers like a human hand?
  
• Are Manatee bones different from yours?
  
• Can Manatees really "walk" on their flippers? Do you know any other marine
  mammal that does this? Can you?
  
• Will Manatees in two parts of Florida have similar amounts of body fat?

Link to: Manatee Adaptations: Skeleton and Flippers and Fat

Did you know that barnacles can also live on manatees' skin? Have you ever seen a barnacle up close? They look like hard shells that bunch up on the bottoms of boats and on pier posts and shoreline rocks. But they are really much more. Inside the hard exterior, an active living organism exists. And you can actually see it coming, reaching out of the shell, like a feather, combing the sea water for food. (Take a look at this video within the Lesson below)

Barnacles can accumulate in massive amounts on whales, and adult gray whales have had up to a ton of barnacles on one whale's skin. Can you imagine what that would be like? What a drag! Just look at the amount of barnacles accumulated on this buoy!

	Moss on a manatee
Barnacles on a manatee Photo Credit: Naples Daily News	Barnacles on a buoy Photo Credit: FWC & NOAA

Fortunately, barnacles do not accumulate as much on the skin of manatees. But why? Take a look below, and think back on what you learned already about how a manatee's migration is affected by the salinity of the water. Then come back and try the Journaling Question below:

• All About Barnacles

Try This! Jounaling Question:
Why do barnacles accumulate more on whales and less on manatees? Think about the locations that whales swim compared to manatees. How are these locations different and why? And what difference would that make on whether barnacles attach or not? Are there other things to consider?

"Hi Students-
The manatee season at Blue Spring came to an end this year on March 14, so it's been a little lonely as far as manatees go. I'm working on a summary of the season now.

But in the meantime, I've gathered this data for several days leading up to the season's end. Can you figure out what factor led to fewer manatees swimming into the Run? Here's a hint-- the same conditions that operated to bring the manatees into the Run now act in reverse to send them out of the Run. To illustrate, see if you can answer:

Challenge Question #19:
"In the data chart below, match the River water temperature with the correct date/line? The temperatures to select from are: 15.7, 19.4, 17.8, 16.1, 18.5, and 18.2."

Date	Air Temp Low(C)	Air Temp High(C	River Temp (C)	Run Temp. (C)	# of Manatees
02/20	2	20		22.5	128
02/21	4	18		22.4	88
03/12	2	23		22.6	39+
03/13	7	26		22.5	17
03/14	9	27		22.5	3
03/15	9.8	27.5		22.5	0

*(All temperatures are in degrees Celcius; "nt" = temperature not taken)

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

I'll be back again soon."
Ranger Wayne Hartley

• 2003 Mortality Stats
• Descriptions of Mortality Categories (Alert: See Note to Teachers Above)
  

  Challenge Question #20:
  "Fill in the blanks above: What percentage of the total 380 mortalities was caused by each category listed? Which category caused the most deaths?"

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

IMPORTANT: Answer only ONE question in each e-mail message.

1. Address an e-mail message to: jn-challenge-manatee@learner.org

2. In the Subject Line of your message write: Challenge Question #18, (OR #19 OR #20)

3. In the body of EACH message, give your answer to ONE of the questions above.

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