 What
is a manatee?
Manatees belong to the order
Sirenia that also includes the dugong and the extinct
Steller’s sea cow. Three
species of manatee exist:
West Indian, Amazonian, and West African. The West Indian
manatee is divided into two separate subspecies: Florida
manatee and Caribbean manatee. They are thought to be
distinct subspecies because of the large body of water
separating them from one another.
Do manatees have any relatives?
Manatees are distant relatives
of elephants (Domning 1986). You might not think they
look alike but if you use your imagination, you will
notice they share several characteristics. Both manatees
and elephants have tough skin, bristle-like hair covering
their entire body, teeth that are continuously being
replaced and “toe” nails
on each forelimb.
Are manatees related to mermaids?
Manatees might not look like
mermaids to us, but many years ago sailors mistook
manatees for legendary mermaids. Christopher Columbus
was the first person to record the sighting of a manatee
in the new world and was surprised at the not-so-beautiful "mermaid".
Part of the manatee legend remains in the name of their
animal order, Sirenia, which comes from the Greek mythical
legend of sirens who sang songs to lure ships into
rocky shores.
Where are manatees found?
Manatees live in shallow, calm
rivers, estuaries, saltwater bays, canals, and coastal
areas. Manatees move from fresh to salt water with no
problem (Powell 1992). The Florida manatee frequents
most areas of Florida. During the summer months a few
travel as far north as Virginia and the Carolinas. Manatees
can suffer from cold stress in water colder than 68 oF
(20 oC) (Powell 1992). In preparation for winter, manatees
travel to areas with warm water such as natural springs
or man-made power plants. The Florida Power and Light
Company has sighted over 300 manatees together enjoying
the warm water and plentiful vegetation near the Fort
Myers power plant.
How big are manatees?
Manatees are about 4-4.5 feet (1.2-1.4 m) long when
they are born and average 60-70 pounds (27-32 kg). Full-grown
manatees weigh between 800 to 1,200 pounds (360-545 kg)
and reach 10 feet (3.0 m) in length. They can grow to
be as large as 3,500 pounds (1590 kg) and 13 feet (4.0
m) in length (Ridgeway 1985)....WOW!
 How can I tell the difference between a male
and a FEMALE MANATEE?
Male
and female manatees are difficult to distinguish. Biologists
even have a hard time identifying the sexes. If you are
lucky enough to view the underside of a manatee, you
will have the opportunity to locate the position of their
genitals. Males have genitals located closely below their
navel. Females have genitals located above the anus.
The anus of both males and females is located near the
caudal peduncle, the tapered area before the tail. Females
are also identified by the presence of a calf nursing
from mammaries located under their pectoral fins.
How long can a manatee hold its breath?
Manatees
can hold their breath for approximately 20 minutes, however
they regularly breathe every few minutes (Ridgeway 1985).
Don't worry if you see a manatee go under water and not
come directly back to the surface. They often move under
water and surface at a different location out of eyesight.
 Do manatees leave "footprints"?
When manatees swim they create
oval shaped ripples referred to as footprints. This is
a great way to spot manatees, especially since they camouflage
so well with their surroundings. Keep an eye open for
manatee footprints.
Why does algae grow on manatees?
Manatees are slow moving mammals
that frequent the water's surface. Algae thrive in wet
areas with lots of sunlight, which makes the manatee's
back an ideal breeding ground for algae. Would you like
to have algae on your body? It may look uncomfortable
to us, but manatees don't seem to mind the slimy stuff.
Algae may help to block out harmful rays from the sun.
Don't forget your algae next time you go catch some sun!
How do manatees care for their young?
The relationship between a mother and baby is the strongest
social bond created by manatees. A mother manatee will
carry her baby for about 12 months before it is born
(Powell 1992). When born, the baby will weigh nearly
66 pounds (30 kg). A baby manatee is called a calf. The
calf will stay close to the mother for one to two years
to learn travel routes and the location of food, rest
areas and warm water refuges. Females generally give
birth to a single calf every two to five years (Reynolds
1992).
How many Florida manatees are in the world
today?
Manatees and dugongs inhabit
warm waters of the Atlantic, Caribbean, Indian, and
Pacific Oceans. There are approximately 5,000 Florida
manatees in existence. All Sirenians are in danger
of extinction. The Steller’s sea cow,
discovered in 1741, became extinct 27 years later due
to constant hunting pressure (Stejnegar 1887). Steller’s
sea cows lived in Arctic waters and reached a length
of 26 feet (8 m). Man has hunted manatees, Steller’s
sea cows, and dugongs for their meat, blubber, bones
and hide.
Does
the government protect manatees?
 Both the Marine Mammal Protection Act of 1972 and the Endangered
Species Act of 1973 protect manatees. It is illegal to
harass, hunt, kill, capture, or collect manatees. In 1978,
Florida legislature established the Florida Manatee Sanctuary
Act that helped to establish speed zones and sanctuary
areas. Today there are twenty-two manatee wintering sites
in Florida that aid in the protection of this species by
not permitting boats, swimmers, or divers in these areas.
CAUTION: Manatees frequent this area.
While boating, you may see signs
warning of manatees in the area. The guidelines are provided
to protect manatees from humans. About 25% of manatee
deaths are caused by boat collisions each year (Ackerman
et al 1995). Signs are posted in hopes that boaters will
be responsible by watching for manatees and reducing
their travel speed in areas where manatees are often
found.
Is it okay to give manatees food and water?
Manatees, like many of us, seem to be curious. They
appear to seek out humans, but we must think about their
well being rather than our own enjoyment. Manatees are
herbivores and feed on over 60 species of aquatic plants
and algae found in their natural environment. By offering
water hoses or lettuce to attract manatees, we are placing
them in great danger.
Most of us who have access
to a hose near the water live in areas frequented by
boats. Basically we are inviting manatees to "play in the traffic”.
Manatees have survived successfully without hoses or
lettuce for nearly 45 million years. Feeding marine
mammals is illegal according to the Marine Mammal Protection
Act.
What should I do if I see a manatee?
Enjoy the moment and appreciate their grace and beauty.
Do not reach out to the manatee. You may teach him/her
that all people are kind and respectful, which is unfortunately
not true! The best way to enjoy their company is to observe
them from a distance.
What should I do if I find an injured manatee?
The first thing you should do is take a few minutes
to observe the manatee. If possible, draw a sketch. Where/what
is the injury? Is it affecting his/her ability to move?
Are there other manatees in the area? Have you seen the
manatee dive or eat? These are just a few of the questions
that might be asked by a member of the manatee assessment
team. The next step is to call for help by contacting
the Florida Fish and Wildlife Conservation Commission
at 1-888-404-FWCC. They will notify
the appropriate people to assess the situation.
Why are certain manatees tagged?
In order to rescue a manatee, it is often necessary
to tag the animal. The tag is connected around the base
of the tail and designed to break free if it becomes
entangled or caught. There are two types of tags: radio
and satellite. Radio tags are used for short term, local
tracking. With a radio tag, we can track the manatee
to a place where it is safe to rescue. Satellite tags
are used for long-term, possibly distant tracking. By
satellite tagging manatees, biologists can study and
observe the traveling patterns and health of released
manatees.
REFERENCES
Scientific Papers:
Ackerman, B.B, S.D. Wright,
R.K. Bonde, D.K. Odell and B.J. Banowitz 1995. Trends
and patterns in mortality of manatees in Florida 1974-1992.
Pages 223-258 in T.S. O’Shea, B.B. Ackerman,
H.F. Percival, editors. Population Biology of the Flroida
manatee: information and technical report 1. National
Biological Services, Ft. Collins, Colorado.
Domning, D.P. and L.C. Hayek. 1986. Interspecific and
intraspecific morphological variation in manatees (Sirenia:
Tricechus).Marine Mammal Science 2(2):
87-144.
Domning, D.P. 1982. Evolution of manatees: a speculative
history.Journal of Paleontology. 56(3):
599-619.
Flamm, R., ET. Al. 2000. Aerial
videogrammetry from a tethered airship to assess manatee
life- Stage structure. Marine Mammal Science.
16(3): 617-630.
Marsh, H., G.E. Heinsohn and L.M. Marsh. 1984. Breeding
cycle, life history and population dynamics of the dugong.
Dugong dugon (Sirenia: Dugongidae).Australian
Journal of Zoology. 32: 767-788.
Marsh, H., C.A. Beck, and T. Vargo.
1999. Comparison of the capabilities of dugongs and West
Indian manatees to masticate sea grass. Marine
Mammal Science. 15(1): 250-255.
Marsh, H. 2000. Evaluating management
initiatives aimed at reducing the mortality of dugongs
in gill and mesh nets in the Great Barrier Reef World
Heritage Area. Marine Mammal Science.
16(3): 684-694.
McClenaghan, L.R., and T.J.
O’Shea. 1988. Genetic
variability in the Florida manatee (Trichechus manatus). Journal
of Mammalogy. 69(3): 481-488.
O’Shea, T.J., et al.
1985. An analysis of manatee mortality patterns in
Florida, 1976-1981.Journal
of Wildlife Management. 49(1): 1-11.
Smith, A., and H. Marsh. 1990.
Management of traditional hunting of dugongs {Dugong
dugon (Muiller, 1976)} in the northern Great Barrier
Reef, Australia. Environmental Magazine. 14(1):
47-55.
Stejneger, L. 1887. How the great northern
sea cow (Rytina) became exterminated.The
American Naturalist. 21(12): 1047-1054.
Scheffer, V.B. 1973. The last days of the sea cow.Smithsonian.
3:64-67.
U.S. Fish and Wildlife Service. 1989. Florida
manatee (Trichechus manatus latirostris) recovery
plan. Prep.
By the Florida manatee recovery team for the U.S. Fish
and Wildlife Service, Atlantic, Georgia.
Books:
Dietz, Tim. 1992. The call of the Siren: Manatees
and Dugongs. Fulcrum Pub. Golden, CO. 196 pgs.
Powell, James, 1992, Manatees:Natural
History and Conservation, Worldlife Library
Reynolds, John E. III., and Daniel
K. Odell. 1991, Manatees
and Dugongs. Facts on File. New York. 192 pgs.
Ridgeway, Sam H. and Sir Richard Harrison, eds. 1985.
Handbook of Marine Mammals, Volume 3: The Sirenians and
Baleen Whales. Academic Press. Orlando, Florida.
Ripple, J. 1999. Manatees and dugongs of the world.
Voyager Press.
Loran, W (Sea World Education
Department). 1998. “Siren’s
Song: The Story of Manatees.”
Van Meter and Victoria Brook. 1987. The West Indian
Manatee in Florida.
Florida Power & Light
Company, Miami, Florida.
Children’s
Books:
Haley, J. 1996. J. Rooker Manatee. Focus Publishing.
Tate, Suzanne. Mary Manatee: A Tale of Sea Cows. 1990.
Nags Head Art, Nags Head. 28 pgs.
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