Answers from the Manatee Expert Nancy Sadusky, Save the Manatee Club

A. In the winter, usually November through March, manatees are concentrated primarily in Florida. Manatees are susceptible to cold-related disease, and in the winter, gather near warm water sources such as natural springs or warm water effluents of power plants. Water temperatures below 68 degrees usually cause manatees to move into these warm water refuge areas. Individual manatees often return to the same wintering areas year after year. In the summer months, manatees are much more widely distributed and can be found as far west as Alabama and Lousiana and as far north as Viginia and the Carolinas.

Q. What is the average weight of a manatee?

A. The average adult manatee is about 10 feet long and weighs about 1,000 pounds.

Q. How do manatees produce babies?

A. Manatees do not form permanent pair bonds. During breeding, a single female will be followed by a group of a dozen or more males, forming a mating herd. They appear to breed at random during this time. Although breeding and brith may occur at any time during the year, there appears to be a slight spring calving peak. Manatees usually bear one calf -- twins are rare. Intervals between births range from two to five years, and the gestation period is approximately 13 months. Mothers nurse their calves for a long period and a calf may remain dependent on its mother for up to two years. Scientists believe females do not become sexually mature until five years of age. Males are mature at approximately nine years of age.
Largo High School
shapiroa@concentric.net

From: FLORIDA
Q. where do the manatees migrate?

A. see above answer

Q. how long does it take for the manatees to get to there destination?

A. It depends on where they are going. Manatees are slow-moving animals. It is estimated that manatees can travel up to 20 mph in short bursts, but they usually travel between 3-5 mph.

Q. How do they get prepared for the long journey?

A. Manatees don't really need to get prepared for the journey, because they find their food source (seagrass and other aquatic plants) along the way. Largo High School shapiroa@concentric.net

From: VERMONT
Q. Grade Three from Ferrisburgh Central School wants to know if manatees have teeth?

A. They do, and one of the interesting things about manatees is that they have what is known as "marching molars." Their teeth are unique because they are constantly replaced. They form at the back of the jaw, wear down as they move forward, and eventually fall out! Tooth replacement is an adaptation to the manatee's diet of abrasive plants that are often mixed with sand.

Q. Grade Three from Ferrisburgh Central School, Ferrisburgh Vermont wants to know how much manatees eat in one day?

A. It is estimated that manatees can eat about 10-15% of their body weight in vegetation daily. So a 1,000 pound manatee would eat between 100-150 pounds of food a day!

Q. Grade Three from Ferrisburgh Central School, Ferrisburgh, Vermont wants to know how deep manatees can go in the water?

A. Manatees are usually found in waters that are 3 to 7 feet deep. Manatees are found in both salt and fresh water. Along the coast, manatees tend to travel in water that is 10-16 feet deep, and they are rarely seen in areas over 20 feet deep.
Ferrisburgh Central School
lthurber@panther.middlebury.edu

From: COLORADO
Q. How do people tell manatees apart?

A. Sadly enough, most adult manatees living in the wild bear scars from at least one watercraft collision. In fact, manatee scars are so commonplace, researchers use them as a method of individual identification.

Q. How far can manatees swim in a day?

A. It depends on the individual manatee. Just like humans, some manatees are more predisposed to traveling than others. Some manatees are being tracked using a satellite transmitter. This is what Jim Reid and Cathy Beck from the Sirenia Project are doing. As a result, researchers have been able to record some interesting manatee movements. One manatee made a 150-mile trip in less than 4 days on one occasion. She swam nearly 45 miles per day!

Q. Why do they grow green moss on there bodies?

A. Manatees that are found in fresh water often have algae growing on their backs. Manatees that are found in salt water will often have barnacles attached to them -- just like boats found in those waters! Crested Butte shoffman@tomichi.ghs.gunnison.k12.co.us

From: MASSACHUSETTS
Q. How much do manatees weigh when they are born?

A. At birth, manatees are three to four feet long and weigh between 60 and 70 pounds.

Q. What is the record weight of a manatee?

A. Adult manatees have been known to exceed lengths of 13 feet and weigh over 3,500 pounds.

Q. What is the record age of a manatee?

A. Scientists believe that manatees are capable of living for 60 years or more. One manatee living in captivity is now over 48 years old.
Fayerweather Street School
swheel@roscoe.bu.edu

From: MINNESOTA
Q. Have scientists decided what killed so many manatee last year off the coast of Florida? Can anything be done to prevent such a large death rate this year or any other year?

A. A single catastrophic event in 1996 was responsible for 151 manatee deaths. These manatee deaths were attributed to red tide, a term used for the proliferation or "blooms" of tiny marine organisms called dinoflagellates. The organism's pigments can cause the water to appear red, green, or yellow. Microscopic, but found in great abundance, they give off a toxic byproduct that affects the central nervous system of creatures in the area of the bloom. The red tide epizootic began on March 5 and continued through April 28 along Florida's southwest coast, wiping out approximately 15% of the known west coast population of manatees. In 1982, another outbreak of red tide was believed to have contributed to the death of 37 manatees. Over the years however, red tide manatee mortality events have been rare. Red tide is currently considered to be a natural event and, therefore, may not be preventable. But scientists are currently looking at possibilities to reduce the risk to manatees during red tides. Monitoring and prediction of red tide distribution has been deemed crucial. The possibility of reducing water salinity in certain areas is also being investigated as red tide requires high salinity water to survive and does not do well in water less than 2.5% salt like brackish or river water. plymouth middle school sandiand@eta.k12.mn.us

From: COLORADO
Q. How cold or hot can the water get before the manatee have to move to different waters? And how far are they capable of traveling in one weeks time?

A. See above answers.

Q. How long do manatees live?

A. See above answer.

Q. What do the manatees eat?

A. Manatees are herbivores (plant-eaters), feeding on a large variety of submerged, emergent, and floating plants. Seagrass beds are important feeding sites for manatees. Some favorite foods of manatees include: Marine vegetation: Manatee grass, Turtle grass, Shoal grass, Widgeon grass. Freshwater vegetation: Hydrilla, Tapegrass, Water hyacinth, and Water lettuce.
Angevine middle school
sands@ucsu.colorado.edu

From: FLORIDA
Q. Do manatee's ever eat plankton or small fish?

A. No. Manatees only eat plants. (See above answer.)

Q. If a manatee is under weight does it effect their breeding, or cause them to get ill?

A. If manatees are underweight, or known to be losing weight, then this is often an indication that they are ill and need treatment.

Q. Do manatee's have any predators?

A. No. Manatees have no natural enemies.

From: TEXAS
Q. Dear Journey North, Does a manatee's skin ever change color? If so, what causes this change?
Sincerely,
Jenny Jamison

A. When manatees are born, they are a gray-black in color. Within a month they change to gray. Manatee adults range in color from gray to brownish-gray, and some manatees found in fresh water have green algae growing in their backs!

Q. Dear Journey North,
If manatees are herbivores, why do they weigh so much?
Sincerely,
Jennifer Wayne

A. Researchers believe that the manatee's large size probably evolved as a result of being aquatic and having a herbivorous (plant-eating) diet. Manatees have a low metabolic rate and must eat a lot of plants to conserve heat and make up for the energy they lose digesting them.
Valley Creek Elementary
dpalmer@mckinney.isd.tenet.edu

From: MINNESOTA
Q. My name is Kevin. I am in sixth grade and I go to Belle Plaine Elementary. What do manatees do when you go near them when you are swimming?

A. Just like humans, individual manatees will probably have different reactions. However, at Save the Manatee Club, we don't encourage swimming with manatees. Manatees are an endangered species and, according to the Endangered Species Act (ESA), it is illegal to touch endangered species or harass them in any way. Therefore, we believe the best way to observe manatees and other wildlife is to observe them from a distance rather than get in the water with them.

The reason we do is that interactions with humans can be harmful for manatees. If manatees become accustomed to being around people, it can alter their behavior in the wild, perhaps causing them to lose their natural fear of boats and humans and making them open to potential harm. Most people would never harm manatees, but not everyone likes manatees and feeding them, touching them, or giving them water could encourage them to swim up to people who might be cruel to them.
Belle Plaine
0716bpel@informns.k12.mn.us

From; FLORIDA
Q. How many manatees are there left in the world?

A. The last aerial survey of West Indian manatees in Florida showed that there are approximately 2,229 manatees. West Indian manatees belong to the scientific order Sirenia. Other sirenians in the world include the Amazonian manatee found in South America; the West African manatee found in Africa; and the dugong, found in the Indian and Pacific Oceans. Manatees in other countries have not been surveyed as well as those in the United States, therefore we don't know exactly how many manatees there are in the world. However, we do know that all sirenian species in the world are listed as "endangered" or "vulnerable" by the International Union for the Conservation of Nature and Natural Resources. This is an independent group representing over 100 countries involved in the conservation of wild living resources.

Q. Why do the manatees need to migrate to warmer water when it starts getting colder?

A. See above answer.

Q. What is the coldest temperature a manatee can handle?

A. See above answer.
Largo High School
shapiroa@concentric.net

From: VERMONT
Q. Is the Doggon Manatee a real manatee?

A. Like West Indian manatees, dugongs are members of the scientific order Sirenia. Dugongs have smoother skin than the West Indian or West African manatee, they also have a split tail fluke like a dolphin, and they can have tusks. Dugongs are found in marine habitat in the Indo-Pacific region near Australia and feed on marine seagrasses.

Q. How many Manatees are killed each year?
Vergennes Union Elementary School
amaurer@vergennes.k12.vt.us

A. That amount varies. Here are the manatee mortality figures since

1990: 214
1991: 175
1992: 167
1993: 147
1994: 195
1995: 203
1996: 415

From: IOWA
Q. Our group is researching the manatee as we track the migration this spring. We were wondering...What is/are the function(s) of the manatee's whiskers?
Thank you
Sara VonAhsen 8th grade Life Science Class Jefferson-Scranton Middle School Jefferson, Iowa.

A. Manatees' whiskers are not that long, so they do not probably serve the same purpose as a cat's whiskers would, for example. It is likely that they are rudimentary, meaning the whiskers were probably necessary at one point in time but are slowly disappearing. Manatee are believed to have evolved from a wading, plant-eating animal, so perhaps whiskers were utilized on this earlier relative.
Jefferson-Scranton Middle School
gerry_stein@qmail.jefferson-scranton.k12.ia.us

From: FLORIDA
Q. During the summer and fall of 1996, a lot of manatees died in Florida. I heard that this decline was due mainly to diease. Is this true? If so, what was the disease?

A. See above answer.

Q. What is the manatee's gestation period?

A. The gestation period is approximately 13 months.

Q. What is the main diet of the manatee?

A. See above answer.

From: NEW JERSEY
Q. Has anyone ever kept a manatee in a tank(like with some dolphins)? If so, were the manatees playful or cooperative?
(Submitted by Karin Palmblad, Iselin Middle School, 7th grade.)

A. I have never heard of a manatee being kept in a tank with dolphins. It is illegal to hold manatees in captivity. However, some manatees live in captivity that have been injured and cannot be released into the the wild for life-threatening reasons. Like humans, these manatees have individual personalities.

Q. How much do baby manatees weigh when they are born? (Submitted by several students at Iselin Middle School, 7th grade.)

A. See above answer.

Q. Where did the word "manatee" come from? Submitted by Edgar Arryo, Iselin Middle School, 7th grade.

A. The name manatee probably comes from the Carib language. Their word "manati" means "woman's breast." Iselin Middle School ims@gorgon.com

From FLORIDA
Q. Why are manatees called "sea cows?"

A. "Sea cow" is a common term for manatees and dugongs. This name likely comes from the fact that manatees are herbivores (plant-eaters), as are cows.

Q. How can manatees go such a long period of time without taking a breath?

A. Manatees, like other marine mammals, do most of their feeding underwater and must be able to hold their breath long enough to feed efficiently. Manatees may rest submerged at the water bottom or just below the surface, coming up to breathe on the average of every three to four minutes. When manatee are using a great deal of energy, they may surface to breathe as often as every 30 seconds. However, they have been known to stay submerged for up to 20 minutes. Marine mammals have a number of adaptations that allow them to stay under water longer than the average land-dwelling mammal. The manatee's lungs lie along its backbone instead of along its rib cage as found in most mammals. The lungs are long, wide, and thin. An usual anatomical feature of sirenians is that each lung is in a separate cavity with a separate diaphram. Scientists do not know whether these cavities can function independently, but we do know that manatees can have severe infections in one lung even though the other seems to function normally. Besides breathing, the lungs help the manatee with buoyancy control. Intervals between breaths is prolonged by replacing a large percentage of the air in the lungs with each breath. Studies have shown that manatees can renew about 90% of the air in their lungs in a single breath as compared to humans at rest who generally renew about 10% of the air in the lungs in a single breath.

Q. Why can't manatees adapt well to cold water?

A. The manatee's metabolic rate is unusually low compared with other mammals. This may account for its susceptibility to cold.

From: MINNESOTA
Q. In terms of evolution, how long have manatees been around? Were they around with the dinosaurs?

A. It is estimated that manatees and their relatives have been on earth for approximately 45 million years.

Q. Why does it take the manatees so long to reach the age where they can reproduce, particularly the males?

Female manatees are not sexually mature until five years of age. Male manatees are mature at approximately nine years of age. Manatees do not develop the physical capabilities necessary for reproduction until they reach this age.

Q. If a mother manatee died leaving young, would another manatee take over the care for the young?

A. This has occurred, but it depends on the individual manatee female. Some will adopt an orphaned calf, and some will not.
Fosston High School
mmenzies@fosston.polaristel.net

From: FLORIDA
Q. How do manatees communicate?

A. Manatees communicate through sound, sight and probably taste, touch, and smell. Manatees emit sounds underwater that are believed to be used in communicating with one another. Manatee sounds can be described as chirps, whistles or squeaks. Vocalizations may express fear, anger, or sexual arousal. They are also used to maintain contact, especially when manatees are feeding or traveling in turbid water. Especially common are vocalizations between a mother and her calf. In fact, a mother and calf once separated by a flood gate vocalized constantly for three hours until they were reunited.

Q. Which river in Florida has the highest population of manatees?

A. Manatees are migrating animals. During the summer months, manatees range throughout the coastal waters, estuaries, bays and rivers of both coasts of Florida. Studies of individual manatees show that many manatees have preferred habitats that they return to year after year. Aerial surveys of manatee distribution show that a large percentage of the manatee population frequent the natural springs of the Crystal and Homosassa Rivers on Florida's west coast in the winter time, although manatees can also be found in the St. Johns River, the Banana and Indian Rivers, and the Intracoastal Waters on Florida's east coast.

Q. Are there enough manatee sanctuaries? How do you feel about the attempt to close or limit some sanctuaries?

A. The public aquisition of critical habitat and the creation of manatee sanctuaries is very important in helping to save manatees from extinction. Manatees must have safe, protected areas away from harassment, boat traffic and strong currents. However, this shelter continues to become harder and harder for manatees to find because of coastal development. To my knowledge, there have not been many attempts to close or limit manatee sanctuaries. In a couple of instances at present, recreational use, such as the opportunity to dive or fish, may be in conflict with protecting manatees in a proposed sanctuary. However, even in important manatee sanctuaries such as the Crystal River National Wildlife Refuge, manatees may not be adequately protected. Heavy use of this national wildlife refuge by divers in the winter months, for example, may be driving manatees away from the warm water refuge areas they need for survival or may be causing them to spend an inordinate amount of time in the refuges instead of leaving them to feed.
Oak Hall School
ohssci@gnv.fdt.net

From: FLORIDA
Q What time of year do manatees migrate?

A. In the winter, usually November through March, manatees are concentrated primarily in Florida. Manatees are susceptible to cold-related disease, and in the winter, gather near warm water sources such as natural springs or warm water effluents of power plants. Water temperatures below 68 degrees usually cause manatees to move into these warm water refuge areas. Individual manatees often return to the same wintering areas year after year. In the summer months, manatees are much more widely distributed and can be found as far west as Alabama and Lousiana and as far north as Viginia and the Carolinas.

Q. What is the average weight of a manatee?

A. The average adult manatee is about 10 feet long and weighs about 1,000 pounds.

Q. How do manatees produce babies?

A. Manatees do not form permanent pair bonds. During breeding, a single female will be followed by a group of a dozen or more males, forming a mating herd. They appear to breed at random during this time. Although breeding and birth may occur at any time during the year, there appears to be a slight spring calving peak. Manatees usually bear one calf -- twins are rare. Intervals between births range from two to five years, and the gestation period is approximately 13 months. Mothers nurse their calves for a long period and a calf may remain dependent on its mother for up to two years. Scientists believe females do not become sexually mature until five years of age. Males are mature at approximately nine years of age. Largo High School
shapiroa@concentric.net

From: FLORIDA
Q. where do the manatees migrate?

A. See above answer

Q. how long does it take for the manatees to get to there destination?

A. It is estimated that manatees can travel up to 20 mph in short bursts, but they usually travel between 3-5 mph.

Q. how do they get prepared for the long journey?

A. Manatees don't really need to get prepared for the journey, because they find their food source along the way. Largo High School shapiroa@concentric.net

From: VERMONT

Q. Grade Three from Ferrisburgh Central School wants to know if manatees have teeth?

A. They do, and one of the interesting things about manatees is that they have what is known as "marching molars." Their teeth are unique because they are constantly replaced. They form at the back of the jaw, wear down as they move forward, and eventually fall out! Tooth replacement is an adaptation to the manatee's diet of abrasive plants that are often mixed with sand.

Q. Grade Three from Ferrisburgh Central School, Ferrisburgh Vermont wants to know how much manatees eat in one day?

A. It is estimated that manatees can eat about 10-15% of their body weight in vegetation daily. So a 1,000 pound manatee would eat between 100-150 pounds of food a day. Ferrisburgh Central School lthurber@panther.middlebury.edu