Manatees
What weighs over 1000 pounds, looks a bit like a walrus
with wrinkled, gray-brown, spongy skin, is sometimes
called a "sea cow", is related to an elephant, was mistaken
for mermaids, can eat more than 100 pounds of vegetables
per day, and travels an average of 3 to 5 miles per
hour? Why the manatee, of course!
These
large animals were once thought to be related to walrus
because of the way they look. Today, scientists are able
to identify animals using genetics. Now they know that
manatees are more closely related to elephants than any
other living animal. Scientists believe that manatees
evolved from land mammals that returned to an aquatic
life.
Manatees
are large marine mammals weighing up to 2000 pounds
and reaching more than 12 feet in length. Like whales,
their large bodies can only be supported in their watery
environment. On land, their body weight would crush
their internal organs.
Manatees
are the only marine mammals that are herbivores. Just
to keep their big bodies warm, they have to eat up to
one tenth of their body weight every day. For the typical
manatee that means more than 100 pounds of water plants!
That's equal to more than 200 heads of lettuce!
Warm
Water Mammals
Keeping
warm is a real problem for these animals. Their cylindrical
bodies help conserve heat, but they don't have the blubber
that other marine mammals do. Their metabolism is also
very low, so they don't generate a lot of body heat. As
a result, they can get sick when the water temperature
falls below 70° F. In cold water, they can develop pneumonia,
get too sluggish to eat, and can die. Most manatees live
in warm, tropical waters, but Florida manatees live in
sub-tropical waters that get below 70° F in the winter
months (Dec. through Mar.). Manatees have a behavior which
helps them survive the colder water. In the winter, they
seek out the natural warm springs of Florida's coastal
rivers. They even gather where electric power plants discharge
warm water. To protect manatees, many of these areas are
now Manatee Sanctuaries.
Adaptations
 Manatees are well suited to
their slow aquatic life. They have flexible front limbs
that they use to steer as they swim. They can also use
these limbs to hold their food. Their body ends with a
large paddle shaped tail. With powerful up and down strokes,
they use their tail to push them through the water. Usually
they move along at 3 to 5 miles per hour, but when frightened,
they can move more quickly.
Like
all mammals, manatees breathe air. As a marine mammal,
they must rise to the surface to take a breath. While
resting this happens every 20 minutes, but when they are
active, they need to take a breath every 3 to 5 minutes.
When people breathe, they only change about 10% of the
air in their lungs. When manatees breathe, they change
up to 90% of the air in their lungs. To do this, they
exhale very hard when their nose breaks the surface, much
like a whale or a person snorkeling will do. While they
don't "spout" like a whale will sometimes do, there is
often a cloud of mist. Breathing like this means there
is more fresh oxygen in their lungs, and allows the animal
to stay underwater longer between breaths. Manatees also
have two other special breathing adaptations. They can
only breathe through their nose, and their nostrils have
special flaps that close tightly when they dive.
 A manatee's mouth and teeth
are specially adapted to an herbivorous life. They do
not have front teeth, only special "marching" molars.
Like elephants, they have 4 sets of 6 to 8 molars. As
the front molar wears down from chewing on fibrous plants
and sand, it is shed. The teeth behind it "march" forward
as a new tooth emerges at the back. Without hands, it
can be hard to get food to your mouth. To solve this
problem, manatees have a large, split upper lip. The
left and right sides can move independently to move
the food into place. Last of all, behind the lips special
ridged pads break food into smaller pieces before the
molars finally grind it up.
Reproduction
Manatees
are generally solitary animals. However, when a female
is ready to mate, several males will gather around her
forming a mating herd. After mating, they resume their
solitary lives. There is, however, a strong bond between
cow and calf. After birth, calves stay close to their
mothers, and touching seems to be important to them.
They nurse for nearly a year, and stay with their mother
for up to two years.
At
birth, manatee calves weight 70 pounds (30 kg) and are
50 inches (120 cm) long. They can live to be 70 years
old, weigh as much as 2,000 pounds (500 kg), and be
more than 12 feet (3 m) long. Reproduction is slow for
manatees. Manatees are mature and able to breed at about
10 years of age. The gestation period is one full year
for manatees, and cows give birth only once every 3
to 5 years.
Communication
Manatees
communicate with each other with voices that sound like
clicks and chirps. The sounds they make can be heard
by humans. Communication is especially strong between
a cow and her calf, and that helps the two remain in
contact with each other.
Reference: The Wild Ones Organization
MANATEE
CAM 2
Injured
Florida Manatees
Please call 1-800-DIAL-FMP
If you see a manatee who has become entangled in monofilatment
(fishing line) or crab trap lines.
If
you see boaters speeding in a protected manatee area.
If
you see anyone harassing a manatee in any way.
If
you see a manatee with a pink or red wound. This
means that the wound is fresh.
If
you see a manatee with grayish white or white wounds.
This means that the wound is healing, but the manatee
can still have internal injuries.
If
the manatee is tilting to one side, unable to submerge,
seems to have trouble breathing or is acting strangely.
If
you spot a manatee calf by itself with no adults around
for an extended period of time.
If
you see a manatee tagged with a radio or satellite transmitter,
do not attempt to remove the transmitter. The
tag is designed to come off it if becomes entangled
in something so that the animal will not become trapped.
You can report the tagged manatee sighting, though.
Please
be prepared to give the exact location and time of the
sighting.
Manatee
Links
Manatee, the Gentle Giant site with a lot of information regarding
this beautiful animal.
Great Site for Children Learn about the Manatee and other endangered animals.
Sponsor a Manatee
Take Action for Manatees
Manatee World Great Site with Real Player Manatee Video.
SireNews The Society For Marine Mammalogy IUCN/SSC Sirenia Specialist Group.
U.S. Geological Survey, Sirenia Project Gainesville, FL
Crystal River National Wildlife Refuge Crystal River, FL
The Caribbean Stranding Network
San Juan, Puerto Rico (In English or Spanish)
U.S. Fish and Wildlife Service Manatee Information
The Florida Manatee Recovery Plan (1993)
Visit The Discovery Channel Online Feature: "Manatees in Peril" Go
along with reporter Maryalice Yakutchik as she heads
out with manatee researchers, sits in on a manatee necropsy
(animal autopsy), participates in a health checkup of
manatees at Homosassa Springs State Wildlife Park, and
goes out on a canoe trip with Ranger Wayne at Blue Spring
State Park.
Florida Fish and Wildlife Conservation Commission Bureau of Protected Species
Management
Manatee And Dugong Bibliography
The Smithsonian's National Museum of Natural History
has an online bibliography that lists printed publications
relating to manatees or dugongs. The bibliography
is divided into three categories: technical, general,
and periodicals. Several references are also available
for young students in the general and periodical categories.
A great resource for projects or reports.
U.S. Fish and Wildlife Service Endangered Species Program Home Page
The Brain of the Florida Manatee
Florida Marine Research Institute
St. Petersburg, FL
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