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Manatee Migration Update: March 31, 1999
Today's Report Includes:
- Third Manatee Survey Yields High Count! CQ's # 11 & 12
- So Far, So Good for New Manatees--CQ #13
- The Lone Ranger--CQ #14
- More on Mo: Discussion of CQ #9
- Threats and Risks to Manatees: Discussion of CQ #10
- How to Respond to Today's Challenge Questions
Third Manatee Survey Yields High Count!
"On March 6, observers recorded the second highest number of manatees since 1991 - 2,353 statewide. The highest count ever made was in 1996 when 2,639 manatees were recorded across the state."
Dr. Bruce Ackerman
Dr. Bruce Ackerman reported this exciting news after conducting the THIRD aerial
survey of 1999. This was the first time "manatee researchers at FMRI have been
able to conduct three counts in one winter!"
"Researchers counted 1,397 manatees from the Suwannee River to the Everglades.
This was the highest count ever recorded for the west coast. The east coast count,
from southern Georgia to Biscayne Bay, was only 956 manatees."
Challenge Question #11:
"Researchers already conducted two aerial surveys this winter, so why was Dr. Ackerman so excited to conduct a third survey?"Challenge Question #12:
"What do you think the latest survey data signify to the manatee scientists? Which data are positive? Which data are negative? Explain why."
(To respond
to these questions, please follow the instructions below.)
So Far, So Good for New Manatees
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Xoshi is doing fine too, although she has been an ongoing challenge to track. Xoshi's location signals had stopped shortly after her release. "Xoshi's tag is not sending location information and we have been unable to get a visual on her. We are getting some sensor updates, and transmitter tip data continues to be high, suggesting lots of activity, typically swimming (we just don't know where!)." By March 15, Cathy reported that "Xoshi finally slowed down enough to enable her antenna to stay at the surface long enough to send several signals to the satellite to fix a location. Whew!" But that didn't last for long. As of last week, "Xoshi's on the move again and we are not getting location updates. She spent most of this week on the inshore side of Elliot Key, but started moving north 2 days ago."
Meanwhile, there's still no data from Ivan. However, "Bob and Susan got a visual on Dmitra and Ivan on March 17, and Bob was able to get a new VHF tag on Ivan. If they do separate, that will allow us to find him radiotracking by truck or boat. We are assuming he and Dmitra are still together. It's still a bit cool, not a likely time yet for them to separate."
Crystal, the wild calf who was just tagged on Florida's northwest coast, is also doing fine, as you'll see in Today's Migration Data below. In the meantime, see if you can answer this:
Challenge Question #13:
"Why does Cathy Beck think it's good news that Brian has been following the other manatees?" (Brian's background information.)
(To respond
to this question, please follow the instructions below.)
Today's Satellite Migration Data
(Courtesy
of U.S. Geological Survey's Sirenia Project)
- Go to Satellite Data Table for Knicky
- Go to Satellite Data Table for Jeb
- Go to Satellite Data Table for Dmitra
- Go to Satellite Data Table for Ivan
- Go to Satellite Data Table for Brian
- Go to Satellite Data Table for Xoshi
- Go to Satellite Data Table for Crystal
The Lone Ranger
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Ranger Wayne Hartley |
Challenge Question #14:
"March 17 and March 24 both had very low air temperatures. Why did so many manatees come into the run on 3/17, while so few came in on 3/24?"
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Date |
Air Temp High(C) |
Air Temp Low(C) |
River Temp (C) |
Run Temp. (C) |
# of Manatees |
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03/13/99 |
23 |
9 |
20.3 |
22.5 |
21 |
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03/14/99 |
27 |
19 |
20.4 |
nt |
7 |
|
03/17/99 |
25 |
5 |
18.8 |
22.5 |
48 |
|
03/18/99 |
30 |
10 |
nt |
nt |
8 |
|
03/20/99 |
34 |
12 |
20.1 |
22.5 |
3 |
|
03/21/99 |
32 |
16 |
21.5 |
22.5 |
0 |
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03/24/99 |
31 |
7.5 |
21.5 |
22.5 |
0 |
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03/26/99 |
30 |
16 |
23 |
nt |
0 |
(To respond to this question, please follow the instructions below.)
More on Mo:
Discussion of Challenge Question #9:
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"Activity info, i.e. number of tips, temperature, can be transmitted by just one or two signals from the transmitter (tag) to the satellite. The antenna has to break the water surface just briefly during the pass of the satellite for that information to be transmitted. However, several transmissions have to be received by the satellite in order for location to be determined. So, if an animal is very active or constantly travelling, we get a lot of tips, but no, or not very accurate, location coordinates."
Swimming Like Crazy!
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Mo |
(Poor Mo must have been so tired after swimming so hard for so long! We're so glad he was rescued by Jim.)
Threats to Manatees:
Discussion of Challenge Question #10
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Category of Risk |
# of Deaths |
| Watercraft collisions |
66 |
| Flood gate or canal lock (crushed and/or drowned) |
09 |
| Other human-related causes (monofilament line, litter, poaching, vandalism, culverts or other human-made structures) |
07 |
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| Perinatal (dependent calves under 4.9 feet [150 cm) |
52 |
| Cold Stress |
09 |
| Other natural |
12 |
| Undetermined |
76 |
* Resources: For more information on the risks faced by manatees visit the following WWW sites:
- The Florida Department of Environmental Protection's Florida Marine Research Institute
- Save The Manatee Club
- Remember, call 1-800-DIAL-FMP if you ever spot an injured, orphaned, dead, harassed,or tagged manatee.
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 # 11 OR ( #12, #13 or #14)
3. In the body of the EACH message, give your answer to ONE of the questions above.
The FINAL Manatee Migration Update will Be Posted on April 14, 1999.
Copyright 1999 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form
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