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Manatee Migration Update: March 6, 2002

Today's Report Includes:

Round Up the Airplanes! The Aerial Manatee Count Takes Off
Round up the planes, the people, the dataforms, the maps, the calvary, the kitchen sink!

Field Notes from Dr. Bruce Ackerman:

Hello Students!
The cold weather we were waiting for finally arrived last week! So on Wednesday Feb 27, on very short notice, we sent out word to mobilize 17 aircraft and many hurried volunteers to conduct the first Manatee Synoptic Aerial Survey of the year. Here's the message I sent out to the troops:


Friday is our best/only/last shot at the Synoptic survey for this year.
This is the first decent cold front since about January 9th.
Time to shift into High Gear. Please round up the planes, the people, the dataforms, the maps, the calvary, the kitchen sink, etc.
Sorry for not much warning!!!!!

To plan an aerial survey, we look for the weather conditions to meet our prescription(Rx) for a count. Ideal conditions include very cold weather, a significant drop in water temperature, followed by clear, calm and sunny days. The cold weather is essential because manatees are very susceptible to cold temperatures, which drive them to congregate near warm-water sources such as power plants and natural springs, where observers can make a count. Sunny days move manatees to the water's surface to warm themselves, and calm winds allow smooth waters and good visibility for counting. (See Discussion of CQ #6 at the end of this report)

Unfortunately, conditions for the count on Friday Mar 1 did not meet our ideal prescription(Rx). Weather turned out to be windy and cloudy, which impaired visibility of the observers. The final survey totals are not available right now, but they are scheduled for announcement soon. In the next Manatee report, we'll be ready to compare them to last year's record survey results.

While we wait for this year's final Survey results, see if you can answer:

Challenge Question #8:
"What conclusions can you draw about the size of the Florida manatee population if this year's count is higher than last year? If it's lower than last year? What reasons might cause the count to change from one year to the next?"

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

Dr. Bruce B. Ackerman
Research Scientist
Florida Marine Research Institute
Florida Fish and Wildlife Conservation Commission
St. Petersburg FL 33701-5095

Field Notes from Cathy Beck: Amazing Manatee Migrations

Latest All Manatees Migration Map
(As of March 1, 2002)
Click on Map to Enlarge

Hello Students:
The manatee migrations really were quite remarkable last week! After traveling far and wide since their initial release, four manatees did something very unique, and all on the same day to boot! Plot the recent data on your maps, or take a look at the current maps here.

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

Challenge Question #9:
"What interesting thing did four manatees do in this latest data? Which manatees? On what day? What reasons can you think of for their similar migrations?"

While you're at it, step back and take a closer look at Actual's movements so far this season. Are her movements equally exciting? Then, see if you can answer:

Challenge Question #10:
"How do Actual's movements compare to the movements of the other manatees you're tracking? What reasons can you think of to explain Actual's movements?

(To respond to these questions, please follow the instructions below.)

We'll see you next time!

Cathy Beck
Sirenia Project
Gainesville, FL

Field Notes from Ranger Wayne: Manatees, Gators and Otters?

Good news and sad news from Ranger Wayne

Hello Students,
It's been busy and interesting here at Blue Spring. Since the last report, there has been both good news and sad news. First the good news. On Feb 20 and Feb 28, two manatees, Bertram and Flash respectively, showed up for their first appearance of the season. It's always a relief when an animal returns to Blue Spring each season! Also, I think Lillith is in estrous. And, Peaches gave us an interesting display on Feb 24, when he was seen trying to eat air plants along the banks of the Run--his head and shoulders were out of the water!

We've had some sad news too. On Feb 23, we were notified of a dead manatee near the fishing dock just outside the Run. It was Pippi, the calf of Phyllis. There were no obvious indications of the cause of death, so we'll wait for results of a necropsy. Also, Destiny was showing signs of starvation, so on Feb 28 she was captured and taken to SeaWorld for treatment. This happened to her last year too, and we hope she recovers just like she did before. I'll keep you up to date about her. (Her calf Doom is staying here with us at Blue Spring this time.)

What's for lunch today?
Credit: U. S. Geological Survey
USGS/Florida Caribbean Science Center

We also had an interesting Alligator report. On March 1, visitors reported an alligator eating 1/2 of an otter, or so they thought. But on March 3, I saw the alligator come down the Run with the other half of his "otter". It was actually a raccoon. He looked rather rakish with the coontail hanging out of his mouth. He finished his dinner, while I watched through binoculars.

Here are the most recent Attendance Sheet data. Does the number of manatees in the run continue to respond to river water temperature changes, as you saw in the last Update?


Air Temp High(C)

River Temp (C)

Run Temp. (C)

# of Manatees































Bye for now,

Ranger Wayne Hartley
Blue Spring State Park
Orange City, FL

How Do You Tell One Manatee From Another?
Spinning Knife Blades
(Click image for a closer look)

Last week you read how Ranger Wayne identifies the manatees at Blue Spring by sight. Think you could do that? Well, you'll get your chance today! Ranger Wayne wants you to hop in the canoe and take the Roll Call.

But wait! How do Manatee scientists like Ranger Wayne identify individual Manatees? How do they tell one from another?

Fortunately for the scientists, each Manatee has unique physical features that distinguish it from other Manatees. Unfortunately for the Manatees, most of their unique features are actually scars and injuries the Manatees received in collisions with powerboats. The propeller of a boat is like a spinning knife blade under water. When it strikes a Manatee, the Manatee is cut by the propeller blades, and may even lose a part of it's body, like part of it's tail. A boat motor can also cut a Manatee with a "skeg", which is like a vertical metal fin at the bottom of the motor. If the manatee survives the boat strike, it is left with unique scars, which scientists use for identification.

Underwater Sketching!

Manatee scientists photograph or sketch the scars and features of individual manatees so that they can be identified and studied. The most extensive identification system of this kind is the database maintained by Sirenia Project biologist Cathy Beck. Known as the Manatee Individual Photo-identification System (MIPS), it is a computerized photographic catalog that currently includes over 1,400 wild manatees.

On a different scale, Ranger Wayne takes photographs and maintains a Blue Spring "Scar Sheet", which shows drawings of the identifying scars and features for the Manatees at Blue Spring. (You'll use this below.) And on an even smaller scale, if a scientist spots an unidentified manatee while snorkeling or scuba diving, she can still sketch the manatee's scars and markings on this waterproof plastic sketch template using a grease pencil.

It's Your Turn: You Make the Call! (Roll Call That Is)
Can you tell me who's in the Run today?

It's time to test your Manatee identification skills. Put yourself in Ranger Wayne's place and hop in the canoe. Can you tell Ranger who's in the Run today?

Challenge Question #11:
"Who do you see in the Run today? Can you identify each Manatee in the photos?
Manatee A is ___________
Manatee B is ___________
Manatee C is ___________
Manatee D is ___________
Manatee E is ___________
Manatee F is ___________"

But wait! Before you paddle up the Run and try to identify the Manatees, you'll need a few essential supplies to help you. Be sure you have these: Your Key, Sketch Worksheet, the Scar Sheet, and a few simple instructions to follow (oh, and your life jacket too, of course).

Who's in the Run Today?




D (Two views)




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

A Tale of Two Rivers
What happens when two rivers meet? If you're the St. John's River and the Blue Spring Run--a lot. From the canoe, you would see that the dark water of the St. John's River looks like dark tea, while the clear water of the Run is so clear you can see the bottom and everything in it!

Did you notice on the Attendance Sheets that Ranger Wayne records the changing location of the dark St. John's River water as it meets the clear water of the Blue Spring Run? Ranger Wayne draws heavy dark lines or shading at the top of the Attendance Sheets to show how far the dark River water extends up into the Run.

Attendance Sheets: Can You See the Dark Water?
(Click on images to enlarge)

December 23

December 31

January 5

Challenge Question #12:
"Why do you think the dark river water comes farther up the Run on some days than others? Are there any explanations in the daily data for those days? What is the location of the manatees relative to the dark water?

Need a Hint? Try This!
If you'd like to try something extra, this experiment helps you explore why the dark water comes further up on some days than on others. If you do the experiment, tell us how it went in your answer!

(To respond to these questions, please follow the instructions below.)

Raise Your Flipper When Your Name is Called: Discussion of CQ #4
In this Challenge Question, we asked your help interpreting some of Ranger Wayne's Attendance Sheets:

A) On December 23, there were 20 manatees counted between transect 1 and 2. Each number that Ranger Wayne wrote adjacent to that area on his Attendance Sheet represents a specific manatee there that day.

B) On December 31, Ranger Wayne didn't see a manatee in transects 16 & 18. But, he knew one had been there because he reported that there was a "nose print at T16" and "Feces at T18". A nose print is a mark in the sand underwater, where a manatee has stayed in the same place for a while. As Ranger Wayne says: "For some reason they'll get down there and they'll just bury their nose in the sand, very distinct. If you see one you know one's been up there for a while."

C) On January 15, the potentially dangerous thing that Ranger Wayne recorded seeing in transect 13 was a fish lure.

D) On February 8, Manatee #234 is Richard. Ranger Wayne reported that Richard the manatee had "bad gas yesterday evening."

One Day They're Here, The Next Day They're Gone: Discussion of CQ #5

Listen to Ranger Wayne Explain the Answer
Audio Clip
(.aif format, 1521 K)
(.wav format, 1521 K)

In this question, we asked "Can you see any patterns or trends in the data that explain the reason(s) for the changing number of manatees" at Blue Spring each day.

Ranger Wayne explained that it all relates to the River temperature:

"The magic number is in the river, its 68 degrees. When it gets down to 68 as the cold weather comes on, the manatees start coming in. The lower it gets below 68, the more manatees you're going to see."

Way to go Iselin! Several students answered this question correctly:

New Jersey's Iselin Middle School students Stephen L, Nathaniel, Stephen M, and Alex said that "In the data we saw that the Manatee stayed in the area when the temperature was cold. On December 19, January 31, and February 3 there weren't any Manatees because the temperature of the river was warm. But on January 5, 97 Manatees were found because the temperature of the river was cold.

New Jersey's Iselin Middle School students Prerana, Jason, Allison and Curran also answered correctly: "When the air temperature and river temperatures are high, it seems that there are not a lot of manatees. When the air temperature and river temperature are lower, there seems to be more manatees."

A Rx for Aerial Surveys: Discussion of CQ #6
In this question, we asked why the following conditions are the perfect prescription(Rx) to have an effective aerial census:

1) A prolonged cold front,
2) A significant drop in water temperature, and
3) A sunny and windless day following the cold front

Manatees are extremely cold sensitive, and Dr. Ackerman explains that "the colder water temperatures cause the manatees to seek out warm water sites, and the warmer air of the sunny day encourages them to float. These conditions encourage the manatees to float at the surface, which makes it easier to see and count them."

You got it Ferrisburgh, VT students! Avery and Julie used their own weather experience to answer: "We think that there would be more manatees on the first warm day following a series of cold days because all the manatees would want to come up and travel to another spot to find more food. It would be easier to travel when the weather is nice. For instance, yesterday was the first nice day we have had in a while. It felt like spring. We were all running outside cheerfully when the day before we had been moving slowly in the cold and wind! It's a lot easier to move when the weather is warm."

Cape Romano: Discussion of CQ #7
In this question we asked "What do you think is attracting the manatees to the Cape Romano area?"

New Jersey's Iselin Middle School students Jaime, Kevin, David and Victoria wrote the Menu on Cape Romano: "We think that what is attracting the manatees to the Cape Romano area is the warm and shallow waters producing good food."

Cathy Beck confirmed that Cape Romano indeed has seagrass beds that draw manatees there to feed. Plus its not a bad looking place either--Dean described the manatees feeding there in "gorgeous emerald green water."

Coming in the Next Reports
  • Where Will Your Manatees Travel? Get the Latest!
  • Synoptic Survey Count Results and Issues
  • Did You Identify the Correct Manatees?
  • More From Blue Spring
  • Manatee Adaptations

How to Respond to Today's Challenge Questions

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

1. Address an E-mail message to:
2. IMPORTANT: In the Subject Line of your message write: Challenge Question #8(OR #9 OR #10 OR #11 OR #12)
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 20, 2002

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