Manatee Migration Update: March 5, 2003
Latest Map and Satellite Data
Link to Latest Data and Maps:
Grab Your Boarding Pass and Climb In! Have you ever wondered what it would be like to ride in the airplane for one of the aerial manatee counts? How high would you fly? What kind of plane would you use? What would you watch for? And what possible connection is there between Rice Krispies and doing aerial manatee counts? Now you can find out, and get a real feel for flying in the plane too. Then come back and answer the Challenge Questions below.
(To respond to these Challenge Questions, please follow the instructions below.) In the next report, Dr. Ackerman will challenge you to make an aerial count from photographs. Will you be able to find all of the manatees that his trained expert eye can find? Why are Aerial Manatee Count Numbers Controversial?
There are many factors that can influence the count each year, and weather conditions on the day of the count can severely affect the number of manatees counted, both up and down. Because of this and other important factors to consider, population researchers recognize that the annual synoptic survey is not a complete measure of manatee population or population trends. As Dr. Ackerman said recently, "The counts reflect the number of manatees they are able to locate each year based on weather conditions, nothing more." Nevertheless, every year the manatee data numbers get used by different groups to support different ideas about the current status of the Endangered Manatee population in Florida. We've summarized the high manatee count numbers since 1991, and also what two different groups say those count numbers actually mean in "Be Careful with Numbers." Take a look at this summary, and then see if you can answer the Challenge Question that follows:
(To respond to this question, please follow the instructions
below.) An Unsung Hero: Ranger Wayne Receives Award
Thank you Ranger Wayne for your tireless dedication in helping to conserve
and protect the endangered manatee (and educate us humans too!) How Do You Tell One Manatee From Another?
But wait! How do Manatee scientists like Ranger Wayne and Cathy Beck identify individual Manatees? How do they tell one from another? Get the basics on what to look for and then come back for your turn trying to identify some Blue Spring Manatees below: It's Your Turn: You Make the Call! (Roll Call That Is)
But Wait! Before you paddle up the Run, you'll need a few essential supplies to help you identify the Manatees. Be sure you have these: Your Key, the Sketch Worksheet, the Scar Sheet, and a few simple instructions to follow (oh, and your life jacket too, of course).
(To respond to this question, please follow the instructions below.) Field Notes from Cathy Beck
And Jim Reid returned from the field, and reported that as of last Friday all is well with the remaining tagged manatees. I say "remaining" tagged manatees because now we finally know that Chuck no longer has his tag. Jim reported that a FWS colleague recovered Chuck's tag late on 2/21/03 at 25.926N, 81.507W, just off of Faka Union Canal. Jim had a chance to examine the tag. The tether was broken at the weak link, possibly after it became entangled in mangrove roots, which were all around the area where it was found. Letting the manatee break free from his tag like this is exactly what a weak link is designed to do. It prevents a manatee from getting stuck or hurt if the tag or tether gets caught in something. In the prior week, our manatees were spending more time in the outer grassbeds as the temperature continued to warm. Jim reported that the shallow bays with abundant seagrass are quick to warm and are especially attractive to manatees after cool spells. Anna and Actual spent some time visiting the grass beds near Panther and Round Keys, Gulliver was still favoring the Fakahatchee Bay and East River area, and Thumper apparently is content with the grassbeds near Chokoloskee Pass. As for Tipper, we are wondering if she will ever come south again? I'll let you know if we learn anything more about Chuck. In the meantime, I've included the latest tracking data for all the manatees, and I'll be back again soon with more news on our Manatees. Bye for now. Cathy Beck Teacher Tips: NEW Reading and Writing Connections AND Instructional Strategies Journey North is offering NEW Reading and Writing Connections that utilize research-based instructional strategies to help students develop essential skills as they delve deeply into their understanding of the world through texts with real people, events, and issues. Manatees Are on the Move! Discussion of CQ #8 & #9 In answer to Challenge Question #8, the two manatees that made the long northward migrations were Anna (who swam from Whitewater Bay back to POI) and Tipper (who swam from Whitewater Bay to POI and then farther north all the way up to Gasparilla Sound near Ft. Meyers.) The weather maps reveal that water temperatures had warmed significantly, which takes away the risk of cold temperature illness for the manatees, and allows them to swim to other areas again. For Challenge Question #9, these classes figured out that warm temperatures and food are what took the manatees offshore:
Great observations everyone! In fact, the manatees are finding sea grass beds offshore. And just like you on the first warm days of spring, the warmer temperatures allow the manatees to mover farther and easier than in the colder temperatures. Manatee Interrupted: Discussion of CQ #10
Lots of factors can interrupt satellite tracking signals, including alligators biting and damaging the tags, and other injuries to the manatee and its tag. For Gulliver and Chuck, Cathy Beck explained several different possibilities. "The quality of the location plotted by the satellite varies, depending on whether the Manatee (actually the antenna) is at the surface when the satellite passes--the antenna must reach the surface in order to broadcast the signal to the satellite. Also, data quality can be affected when there are a lot of structures or vegetation that may interfere with the signal." "For Chuck, we discovered his tag had broken away, and it was found in heavy vegetation in the mangrove roots where signals can be interfered with. For Gulliver, signals may also have been interrupted if he had been in a heavily vegetated area for a period of time; or he just might have been on the bottom resting in deep water with his tag submerged when the satellite passes occurred, causing a lack of high quality locality information being transmitted. His signals have resumed." Raise Your Flipper When Your Name is Called: Discussion of CQ #11: A) Ranger Wayne reported that Georgia took someone's jeans off the dock in the Swimming Area. Transect numbers 9, 10 and 11 are the location of the Swimming Area (also known as the "scene of the crime" where Georgia took the jeans.) B) On November 18, Ranger Wayne observed most of the manatees located between the Canoe Basin Barrier (CB) and Transect 2. For Transect 17, Ranger Wayne knew a manatee had been there because he observed Manatee feces there. C) By December 12, the dark water from the St. John's River had pushed farther up into the Run beyond Transect #1, whereas on November 18 the dark water had just barely gone beyond the Canoe Basin Area border. And by December 12, the manatees are located further into the Run, with significant numbers of manatees in Transects 2, 3 and 4, and even in Transects 11-13 too. D) On December 27, the temperature of the River water was now only 14.5 degrees Celsius, as compared with temperatures of 17.5 and 18.7 on December 12 and November 18 respectively. By December 27, the dark river water has pushed even farther into the Run, reaching beyond Transect #3 almost to Transect #4. E) By January 27, the River water temperature is now only 11.0 degrees Celsius, the dark water has reached all the way to Transect #4, and so the manatees are now seen all the way up in the Boil (Transect # 18 and 19), an area they were not yet in back on November 18 or December 12.
Why Does the Daily Manatee Count Change: Discussion of CQ #12 In this question, we asked "Why do you think the number of manatees in the Blue Spring Run changes each day? Can you see any patterns or trends in the data below that explain the reason(s) for the changing number of manatees?"
Coming in the Next Report:
How to Respond to Today's Challenge Questions:
1. Address an e-mail message to: jn-challenge-manatee@learner.org
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