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Frequently Asked Questions
Students Ask and Experts Answer
Contributed by Manatee Expert Nancy Sadusky
Save the Manatee Club
Ways to use in the Classroom

Q. What affects the population of the Manatee, more pollution or boats?

A. Where cause of death is known, watercraft collisions is the single largest category of manatee mortality in the United States. West Indian manatees can swim up to 20 miles per hour in short bursts, but they usually only swim about three to five miles per hour. Because manatees are slow moving, need to surface to breathe air, and prefer shallow water, they are vulnerable to boat hits.

Q. Do the manatees have any mating dances or special sounds during mating season?

A. Manatees do vocalize, but they don't have any sort of mating call or mating dance. They emit sounds underwater that are believed to be used in communicating with one another, and not for navigational purposes. 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 mothers and calves.

Listen to a Manatee

(Courtesy of U.S. Geological Survey's Sirenia Project)



Q. How is global warming affecting the migration and or living habits of the Manatee?

A. On the face of it, global warming could be a good thing for manatees. Since they require tropical and subtropical habitat, global warming could actually increase their habitat area. However, rising water level is also associated with global warming. That means that people living along the coast would probably put up more sea walls, which could be detrimental to seagrass, a necessary food source for manatees.

Q. We have researched Manatees and found that female manatees give birth to one baby. What is the most common manatee baby a manatee can get, a male or female?


A .
With any population in nature, there is a 50 - 50 ratio of male to
female births in manatees. The same is true for humans.


Q. Do manatees migrate to the same place every year?

A. It has been documented that many manatees have preferred habitats that they return to year after year. However, just like humans, manatees have individual behavior. Some years they may choose to visit a different warm water refuge in the winter.

Photo: USFWS

Q. Why can manatees turn only their head?

A. Actually, manatees can turn their whole body by using their flippers.

Q. Is the manatee a relative to any other animal?

A. The manatee's closest land relatives are the elephant and a small rat-like creature called a hyrax. West Indian manatees (found in Florida) are also related to West African manatees, Amazonian manatees, and dugongs.


Q. How fast can a manatee swim?

A. On average, most manatees swim about 3 to 5 miles per hour. However, they have been known to swim up to 20 miles per hour in short bursts.


Q. What do you think is the most fascinating thing you have uncovered about the manatee since you have been researching this creature ?

A. Two things are very interesting about manatees:

 

1) they are the only aquatic mammals that are herbivores, and

2) of all the mammals in the world, manatees and sloths are the only mammals with 6 cervical (neck) vertebrae. All other mammals (even giraffes!) have 7 cervical vertebrae.



Q. Did mantees walk on land long ago?

A. Scientists believe that manatees evolved from a wading, plant-eating animal.

Photo: USFWS



Q. What's the largest number of babies a manatee has ever had? From Sarah, Emily & Stephanie

A. Scientists believe that only one manatee calf is born every two to five years, twins are rare.

Q. What's the oldest a manatee has ever lived?

A. A manatee named Snooty is now over 50 years old.

Q. How do they mate?

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 what is called a mating herd. They appear to breed at random during this time. Breeding and birth may occur at any time during the year, but there appears to be a slight spring calving peak.


Q. How long do they live?

A. Researchers believe that manatees can live 60 years or more.


Q. How young are the calves when they start breeding?

A. Female manatees don't start breeding until they are five years of age. Males are not mature until they are nine years of age.

Q. Unfortunately humans kill manatees. Do they have any other predators?

A. No. Manatees have no natural enemies.

Q. Are there any organizations or laws to help manatees from becoming extinct? Have their numbers improved over the last few years?

A. Manatees are protected under federal law by the Marine Mammal Protection Act of 1972 and the Endangered Species Act of 1973. Manatees are also protected by the Florida Manatee Sanctuary Act of 1978. The Manatee Recovery Plan was developed as a result of the ESA and is coordinated by the U.S. Fish and Wildlife Service. Other major groups that participate in manatee protection efforts include: the Florida Department of Environmental Protection, the U.S. Geological Survey's Sirenia Project, and Save the Manatee Club.

Photo credit:s USFWS
Regarding your question on population, for years now, researchers have believed that the manatee population was somewhere between 2,000 and 3,000 animals. The last aerial survey of the Florida manatee population was done in January of 1998. The survey showed a population count of 2,019 manatees. A synoptic survey is a statewide aerial survey designed to get a head count of individual manatees. The success of synoptic surveys is very dependent on weather conditions. If the weather is cold and clear, then manatees are gathered around warm water sites, making it easier to get a "nose" count. They are not the most reliable way to determine overall manatee population because so much depends on weather conditions, but they are the only available method at present.

Other surveys from past years have yielded the following results:

1991 - 1,465
1992 - 1,856
Jan. 1995 - 1,443
Feb. 1995 - 1,832
Feb. 1996 - 2,639
Jan. 1997 - 2,229
Jan. 1998 - 2,109


Q. What are the kinds and sizes of manatee boat scars? Are any scars curable or do they stay on the manatees forever? (Please include the depth of the boat scars.)

A. Many manatees have "skeg" marks. A skeg is part of a motor on the boat. It extends slightly below the propeller and can sometimes come in contact with the manatee without the propeller making contact, creating a single longitudinal gash. When a manatee gets hit by a boat propeller, it also creates prop wounds which take the form of a parallel series of slash marks. If the injury is deep enough, it can be seen on the manatee forever. If the injury is superficial, it will still be there, but you wouldn't be able to see it unless you got very close as skin would grow on top of it.

Photo credit:s USFWS
Q. What are the different types of speedboats that are dangerous to the manatees?

A. All types of boats that are going too fast are dangerous to manatees. Most manatees only travel about 3-5 mph hour (they can go up to 20 mph in short bursts), so any boat that is traveling faster than 15-20 mph is capable of injuring or killing a manatee.

Q. Is it possible to teach manatees to do tricks? If yes, what tricks can they perform?

A. Manatees are definitely smart enough to learn tricks. Manatee brains don't have convolutions on the surface of their brain that are usually associated with higher intelligence. However, they have a higher gray matter to white matter ratio than any other mammal known, including humans! Since gray matter is the area of the brain where thinking occurs, it could be that manatees are a lot smarter even than us! More research needs to be done to understand the composition of manatee brains and how it relates to their intelligence.

As far as what tricks they can perform, we think the manatee's ability to survive in a hostile environment is a pretty neat trick in itself!

Q. What do manatees do during a hurricane?

A. Researchers believe that manatees are well adapted to the aquatic environment and often seek sheltered waters during rough conditions.

Q. Why are manatees attracted to the sound of motors?

A. They aren't. Reserach has shown that they actually avoid them, when they can.

Q. Are manatees as smart as humans?

A. See above answer on "tricks" question.


Photo credit:s USFWS
Q. Can manatees see color?

A. Good question! I asked our biologist, and she said she believes that manatees do see in color.

Q. How can you tell a female from a male manatee?

A. If you look at the underside of a manatee, referencing from the head to the tail, the genital opening in the male manatee is just below the umbilicus (belly button), and the female's genital opening is just above the anus. That's how you can tell a male from a female.

 

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 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.

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.

Q. Do 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. 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. 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.

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!

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.

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.


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.

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.

Q. Does a manatee's skin ever change color? If so, what causes this change?

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. If manatees are herbivores, why do they weigh so much?

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.

Q. 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.

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.

Q. Is the Dugong 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?

A. That amount varies. Since 1974, biologists have collected mortality statistics for Florida manatees. Researchers have determined both the number of manatee deaths in each Florida county and the probable cause of death for each carcass. Analysis of these data allows tracking of changes and trends in mortality throughout the years.

You can find historical and recent information on manatee mortality by going to: The Manatee Mortality Webpage


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?

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.

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.

Q. Has anyone ever kept a manatee in a tank(like with some dolphins)? If so, were the manatees playful or cooperative?

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?

A. See above answer.

Q. Where did the word "manatee" come from?

A. The name manatee probably comes from the Carib language. Their word "manati" means "woman's breast."

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.

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.

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.

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.

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.

Q. Do 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. 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.




Special thanks Nancy Sadusky,
Save the Manatee Club for providing her time and expertise in responding to your questions.
Nancy Sadusky
Communications Director
Save the Manatee Club
500 N. Maitland Ave.
Maitland, FL 32751
For more information or to Adopt-A-Manatee:
1-800-432-JOIN (5646)

 

 
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