Scientific Classification€¦ · Manatees and dugongs are found in warm waters around the world....

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Habitat & Distribution

Physical Characteristics

Senses

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Behavior

Diet & Eating Habits

Reproduction

Birth & Care of Young

Longevity & Causes ofDeath

Conservation &Research

Appendix

Books For YoungReaders

Bibliography

ManateeScientific Classification

Class Mammalia

Order Sirenia

1. The living sirenians consist of three species of manatees and one species of dugong.

2. The Greek name for this order is derived from the sirens of Greek mythology. Sirens were sea nymphswho lured sailors to their island with their mesmerizing songs.

Sirenians are named for the sirens of Greek mythology.

Family Trichechidae And Dugongidae

1. All three species of manatees belong to the family Trichechidae.

2. The family Dugongidae includes the dugong found in the Indian and western Pacific Oceans. A secondspecies, the Steller's sea cow was discovered in 1741 and hunted to extinction by 1768. This species livedprimarily in the Commander Islands of the western Bering Sea.

Genus, Species

1. Trichechus manatus, the West Indian manatee. There are two subspecies of the West Indian manatee:the Florida manatee (Trichechus manatus latirostris) and the Antillean manatee (Trichechus manatusmanatus). These subspecies are distinguished by differences in cranial measurements and by theirgeographic distribution.

2. Trichechus senegalensis, the West African manatee. About the same size and shape of the West Indianmanatee, the West African manatee differs in some important respects: position of the eyes, snout, andcranial bones.

3. Trichechus inunguis, the Amazonian manatee. The Amazonian manatee is the smallest of themanatees. Several physical characteristics distinguish it from the other two species. It lacks nails on itspectoral fins, and usually has whitish patches on its underside.

Fossil Record

Scientific Classification

PARKS KIDS SHOP ANIMALS CARE LANGUAGE

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1. The fossil record of sirenians is incomplete, and the relationship between manatees and their ancestorsis poorly known.

Sirenian fossil records are incomplete andcontinue to be an area of study.

2. Even though the oldest known sirenian fossils were found in Jamaica (Prorastomus sirenoides), it islikely that sirenians originated in Eurasia or Africa. During the middle Eocene period (45 to 50 millionyears ago), the ancestors of manatees probably reached South America (Savage et al., 1994).

3. Studies using biochemical analysis of proteins show that the closest modern relatives of sirenians areelephants, aardvarks, and small mammals known as hyraxes. These four orders of mammals aresometimes considered "subungulates", meaning they may be evolutionary offshoots of a primitiveungulate (hoof) stock. The anatomical characteristics they share include the lack of a collar bone andthe presence of nails instead of claws. Scientists once mistakenly thought manatees were closely relatedto walruses based on facial similarities (Reynolds and Odell, 1991).

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Senses

Adaptations

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Behavior


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Appendix


Bibliography

ManateeHabitat & Distribution

Distribution

1. All living sirenians are found in warm tropical and subtropical waters (Nowak and Paradiso, 1983).

Manatees and dugongs are found in warm waters around the world.In the United States, manatees are most common in Florida waters.

2. The West Indian manatee was once abundant throughout the tropic and subtropical western North andSouth Atlantic and Caribbean waters. However, the manatee's numbers have been greatly reduced.Today, the West Indian manatee is listed as an endangered species throughout its range.

The range of the Florida manatee is primarily peninsular Florida but extends as far north as RhodeIsland. Manatees have been rescued near Houston, Texas, and Mississippi.

Antillean manatees have a patchy distribution throughout the Caribbean, Mexico, and northeasternSouth America. The southern range extends through Central and South America to Brazil.

3. West African manatees range from Senegal to Angola, on the west coast of Africa.

Amazonian manatees are the only species of manatee confined to fresh water. They inhabit theAmazon Basin, mostly in Brazil. They are uncommon or close to extinction in Peru, Ecuador, andColombia.

Habitat

1. The West Indian and West African manatees inhabit rivers, bays, canals, estuaries, and coastal areasrich in seagrass and other vegetation. They can live in fresh, saline (salt), and brackish waters. Theymove freely between extremes.


















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West Indian manatees freely move betweenfresh, brackish, and saline waters.

West Indian manatees may be found in any waterway over 1 m (3.25 ft.) deep and connected to thecoast. They prefer waters with temperatures above 21°C (70°F). Florida manatees rarely ventureinto deep ocean waters. However, manatees have been spotted as far offshore as the Dry TortugasIslands, approximately 81 km (50 mi.) west of Key West, Florida.

West African manatees live in quiet coastal areas, large rivers, lagoons, and connected lakes, wherethe water temperature is above 18°C (64°F).

2. The Amazonian manatee is restricted to fresh water. They are most common in floodplain lakes andchannels in white-water river systems with water temperatures ranging from 25°-30°C (77°-86°F).

3. The patchy distribution of manatees throughout all their ranges is due to their search of suitablehabitat: plentiful aquatic plants and a freshwater source of water to drink.

Migration

1. Florida manatees move into warmer waters when the water temperature drops below about 20°C(68°F).

Manatee calves learn migration routes and thelocations of warm water areas from their mothers.

Historically, Florida manatees have migrated south into warmer waters during the colder months ofthe year. On the Gulf coast, manatees congregated at natural warm-water springs. On the Atlanticcoast, manatees headed south of the Sebastian River.

Today, power plant outfalls and other warm-water discharges are important winter destinations formany manatees.

In Florida, more than 200 manatees congregate at some power plants during coldweather. These artificially heated sources have allowed manatees to remain north oftheir historic wintering grounds.

Among the most important of the artificial warm-water discharges are the Florida Power& Light Company's power plants at Cape Canaveral, Fort Lauderdale, Port Everglades,Riviera Beach, and Fort Myers, as well as the Tampa Electric Company's Apollo Beachpower plant in Tampa Bay, Florida (Van Meter, 1989).

2. In dry seasons, West African and Amazonian manatees migrate downstream or into lakes or deeperparts of a river.



3. One manatee known as "Chessie" traveled 3,220 km (2,000 mi.) from Florida to Point Judith, RhodeIsland, and back in 1996. Chessie migrated further north and covered a greater distance than anymanatee ever documented.

Population

1. The Florida manatee census taken in January, 2000, found 2,222 individuals. The 1999 survey was2,353. Scientists believe there may be as many as 3,000 manatees currently in the state of Florida.

2. Populations of all species of manatees have apparently declined over the past hundred years. Thesedeclines are due to such causes as hunting for their meat, destruction of their habitats, boating,pollution, and low reproduction rates. Antillean, Amazonian, and West African manatee populationsare not known due to inadequate scientific research.

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ManateePhysical Characteristics

Size

1. Adult West Indian and West African manatees average about 3 m (10 ft.) in length. Large individualsmay reach lengths of up to 4 m (13 ft.). Average adult weights are approximately 363 to 544 kg (800-1,200 lb.). One particularly large Florida manatee weighed 1,655 kg (3,650 lb.). Females are generallylarger than males.

Adult West Indian manatees average about 3 m (10 ft.) andweigh approximately 363 to 544 kg (800 to 1,200 lb.).

2. Amazonian manatees are the smallest of all three species. They are shorter and more slender. Thelongest specimen measured 2.8 m (9.2 ft.). A large individual weighed 480 kg (1,058 lb.).

Body Shape

1. The manatee's body is streamlined-full around the middle and narrowing to a paddle-shaped tail.

Coloration

1. The true color of a manatee is gray, although it may appear brownish-gray.

2. Amazonian manatees usually have white or pink patches on the belly and chest.

3. Organisms such as algae, which may grow on the skin of slow-moving individuals, alter the body colorand make some manatees look more green or brown.

Pectoral Flippers

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Manatees have small, flexible pectoral flippers that are used forsteering, touching, scratching, and even embracing.

2. West Indian and West African manatees have three or four fingernail-like the toenails on an elephant'sfeet-at the tips of their flippers. Amazonian manatees lack fingernails.

3. Manatee flippers have five digits that are covered by a thick layer of skin. This bone structure is similarto that of toothed whales, seals, and sea lions.

Hind Limbs

1. Hind limbs are absent. Vestigial pelvic bones, which are not connected to the vertebral column, arefound deep in the pelvic musculature.

Head

1. Manatees have no external discernable neck.

2. Manatees do not have external ear flaps. The tiny opening to the ear canal is located several centimetersbehind the eye.

3. The nostrils lie at the end of the snout on the upper surface. They close automatically when a manateesubmerges.

Manatee nostrils close automatically when it submerges.

4. Manatees have a large flexible upper lip. Their lips help guide vegetation into the mouth. Vibrissae(whiskers) are found on the surface of the upper lip. Each vibrissa is separately attached to nerveendings and has its own supply of blood.



Manatees have large, flexible upper lips that are used toguide food into their mouths.

5. Small eyes (about 2 cm or 0.8 in. in diameter) are located on the sides of the head. The iris has a colorranging from blue to brown (Griebel and Schmid, 1996).

6. A manatee's only teeth are 24 to 32 molars located in the back of the mouth. The front molars in eachrow are continually being worn down by the abrasive plants the manatee eats. As the teeth wear down,new molars grow in the back of the mouth and gradually move forward. The replacement processcontinually provides new chewing surfaces as the teeth wear down, and continues throughout themanatee's lifetime. This unusual dental adaptation is found only in the modern manatees, suggestingthat the manatee diet at an earlier time was extremely abrasive.

The front molars in a manatee's mouth are continually worndown by the abrasive plants it eats.

7. In addition to molars, manatees have horny, ridged pads at the front of the upper and lower jaws whichaid in crushing plant materials.

Tail

1. The tail is evenly rounded and forms a paddle shape.

Manatees have rounded, paddle-shaped tails.

2. A manatee swims by moving its large paddle-like tail in an up-and-down motion.

Hair

1. A manatee has sparse hairs scattered over its body, with the largest concentration around the snoutarea.



Manatees have a concentration of hairs around their snouts as well asscattered over their bodies. A substantial nerve network transmits

tactile information from these vibrissae to the brain.

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Adaptations

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Behavior


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ManateeSenses

Hearing

1. The hearing capacities of manatees are not well studied, but it is known that manatees are adapted forhearing low frequency sounds.

2. Manatees have large ear bones that are well developed at birth. Some scientists have suggested,however, that the main area of sound reception is not the small ear openings but rather an area near thecheekbones. A manatee's cheekbones are large and relatively oily, and they are in direct contact withthe ear bones.

3. Hearing is an important sense for young manatees because mother and calf vocalizations are significantin keeping them together. The chirps, whistles, and squeaks used by manatees are probably produced inthe larynx and are often in the 3-5 kHz range.

4. Preliminary studies suggest that manatees have a greater sensitivity to low-frequency sound than anymarine mammal studied (U.S. Fish and Wildlife Service, 1995).

Eyesight

1. Manatees have well-developed eyes. In the water, they can detect objects from tens of meters away.

2. A manatee's retinas contain both rod and cone cells, indicating that they probably have the ability to seeboth dim and bright light. Recent tests suggest manatees can distinguish between blue and greencolors, although the full extent of their color vision is unknown and more studies are needed.

Recent tests suggest manatees can distinguishbetween blue and green colors.

3. A nictitating membrane acts as an extra eyelid for protection.

Tactile

1. Touch seems to be very important for manatees. Body contact is common between mother and calf.Manatees have also occasionally been observed initiating body contact with divers. They have evenbeen seen making contact with inanimate objects such as ropes, buoys, logs, and rocks.

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Touch seems to be important for manatees. They have been observedmaking contact with a variety of inanimate objects.

Taste and Smell

1. The manatee's chemoreceptive capacities (taste and smell) have not been well studied. They have tastebuds on the backs of their tongues and can most likely taste. Studies on manatee food preference atBlue Spring State Park, Florida, indicate that manatees avoid certain plants such as spatter dock, blue-green algae, and waterpennywort that contain natural toxins.

2. Manatees have olfactory tissue on small internal nasal bones, and probably have some sense of smell.The capability for scent discrimination is largely unknown.

3. Some researchers theorize manatees use smell and/or taste to tell if a female is in estrus or "heat",while other researchers believe males respond to low frequency sounds made by females when they areready to mate.

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Senses

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Communication

Behavior


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ManateeAdaptations for an Aquatic Environment

Swimming

1. Manatees are quite agile and maneuver well under water.

2. Florida manatees have been clocked swimming at speeds up to 24 kph (15 mph) for short bursts, butusually cruise about 3 to 10 kph (2-6 mph) or less.

Diving

1. Although manatees are excellent swimmers, the deepest an individual has been seen diving is 10 m (33ft.). They normally feed no deeper than about 3 m (10 ft.) below the surface of the water.

The vegetation manatees eat does not grow in deep water, somanatees feed mostly in waters no deeper than 3 m (10 ft.).

2. All marine mammals have special physiological adaptations for diving. These adaptations enable amanatee to conserve oxygen while under water.

Manatees, like other marine mammals, have a slower heart rate while diving.

In contrast to whales and dolphins, manatees are not deep-diving marine mammals. Therefore,manatees' muscles do not contain the high concentrations of the oxygen-binding protein myoglobinthat is typical of other marine mammals.

Respiration

1. Studies show that manatees renew about 90% of the air in their lungs in a single breath (humans renewonly about 17%).

2. While resting, manatees can stay submerged for as long as 20 minutes, although the average intervalbetween breaths for resting is two to three minutes. More active and smaller manatees breathe moreoften.

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Manatees must surface to breathe. The average intervalbetween breaths is two to three minutes.

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ManateeCommunication

Sound Production

1. Manatees emit sounds under water. The chirps, whistles, or squeaks are probably produced in thelarynx. They seem to make these sounds when they are frightened, sexually aroused, or interacting witheach other.

2. Vocalizations are an integral part of the cow-calf relationship. Cows respond to squeals of their calvesfrom more than 61 m (200 ft.) away.

Manatee mothers have been known to respond to thesqueals of their calves from 61 m (200 ft.) away.

Other Communication

1. Manatees may communicate through sound, sight, taste, touch, and smell.

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ManateeBehavior

Daily Activity Cycle

1. Manatees are nonaggressive, nonterritorial herbivores that spend most of their time feeding (six toeight hours per day) and resting (two to twelve hours per day). The remainder of their day is spenttraveling, investigating objects, and socializing by interacting with other manatees.

Manatees form loosely organized groups with individualscasually gathering and dispersing.

Social Behavior

1. Manatees are best described as semi-social. The basic social unit is a female and her calf. Groups ofmanatees gather and disperse casually. These groups tend to be temporary and vary regarding sex,number, or age. Manatees do congregate at winter warm-water refuges.

Manatees spend most of their day feeding and resting.

2. Manatees have been observed participating in loosely organized, seemingly playful activities such asbodysurfing and follow-the-leader.

Manatee bodysurfing involves groups of manatees riding the powerful currents generated belowflood dams when the gates are partly open. Sessions of bodysurfing can last more than an hour.Bodysurfing manatees frequently nuzzle one another and vocalize between rides.

Follow-the-leader is another form of coordinated behavior in which two or more manatees movetogether in a single file. During this time they synchronize all of their activities including breathing,

Behavior

















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diving, and changing direction.

The basic manatee social unit is a female and her calf.

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Reproduction




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ManateeDiet & Eating Habits

Diet Preferences And Resources

1. Manatees are primarily herbivores. They feed on a wide variety of submerged, emergent, floating, andshoreline vegetation.

2. Manatees in Florida feed on more than 60 species of plants including turtle grass, manatee grass, shoalgrass, mangrove leaves, various algae, water hyacinth, acorns, and hydrilla.

3. In Sierra Leone, Africa, the West African manatee is considered a pest because they consume fields ofplanted rice.

4. Manatees have occasionally been seen to eat foods other than plants. Antillean manatees have beenknown to eat fish from nets and West African manatees have been known to eat clams (Reynolds andOdell, 1991).

All manatees eat vegetation.

Food Intake

1. Manatees consume about 4% to 9% (15 to 49 kg or 32-108 lb. for an average adult manatee) of theirbody weight in wet vegetation daily.

2. Some Amazonian manatees living in deep bodies of water apparently fast during dry seasons(November and December) when water levels drop as much as 9 to 15 m (30-50 ft.), eliminating theiraccess to vegetation.

3. Because manatees have a very low metabolic rate, it is speculated that Amazonian manatees are able tofast for up to seven months if necessary (O'Shea, 1994).

Method of Feeding

1. Manatees feed off the bottom, in the water column, and at the surface. They have been known to cropoverhanging branches, consume acorns, and haul themselves partially out of the water to eat bankvegetation including the leaves of mangrove trees.


















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Manatees feed off the bottom, in the water column,and at the surface.

2. Manatees use their front flippers and large, flexible lips to manipulate vegetation.

3. Horny, ridged pads at the front of a manatee's palate (roof of the mouth) and lower jaw breakvegetation into smaller pieces. Behind the pads, molars grind the food.

Fresh Water

1. Both the West Indian and West African manatees may require a source of fresh water for drinking.Manatees have been seen drinking fresh water from hoses, sewage outfalls, culverts, and alsocongregating at river mouths. Most scientists agree that manatees must periodically have access tofresh water.

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ManateeReproduction

Sexual Maturity

1. Male manatees (bulls) are sexually mature by about nine to ten years, although some have producedviable sperm at two to three years of age.

2. Female manatees (cows) are sexually mature as young as three years of age.

3. As manatee aging studies progress, sexual maturity may be estimated more precisely.

4. Although females are usually larger than males, it is very difficult to tell the sex of an individual animalwithout observing its underside. There is no marked sexual dimorphism other than the position of thegenital openings.

The female's genital opening is located just in front of the anus. Two additional ways to identify afemale are the presence of a suckling calf, or an extremely round appearance during pregnancy.

The male's genital opening lies just behind the umbilicus (navel), about midway down the undersideof the body.

Mating Activity

1. Mating takes place in the water in a variety of postures.

2. Breeding herds consist of one cow in estrus accompanied by several bulls. An estrus female can bepursued for weeks by several males. The cow often twists and turns violently, apparently to escape hersuitors. The bulls meanwhile attempt to remain adjacent to her, presumably competing with each otherto become the first to mate with her.

3. While in estrous, cows may mate with several bulls. Cows do not form permanent bonds with bulls.

Captive Breeding

1. Manatees breed well in captivity, but it is not known how successful the offspring would be if released.Since space is limited at zoological facilities, emphasis is placed on the rehabilitation andreintroduction of injured manatees instead of breeding them.

2. Zoological institutions in Florida are on a voluntary breeding hold. Until the numerous problems arecorrected in the manatee's natural environment, a breeding program will not be beneficial to them.

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ManateeBirth & Care of Young

Gestation

1. A Florida manatee's gestation is approximately 12 months.

Manatees have a gestation of about 12 months and althoughthe calf may be weaned by the end of its first year,it remains close to its mother for up to two years.

Birth Seasons

1. Manatees in Florida and West Africa breed year-round.

2. In Florida, most calves seem to be born during the spring and summer. Most Amazonian manatees areborn between February and May.

Frequency of Birth

1. A Florida manatee female produces a single calf about every two to five years, although females thathave lost or aborted a calf have been known to give birth to another in just one year (Reynolds andOdell, 1991).

2. The birth of twins may occur, but is rare.

Calf at Birth

1. A West Indian manatee calf measures about 1.2 to 1.4 m (4-4.5 ft.) and weighs approximately 27 to 32kg (60-70 lb.).

2. An Amazonian manatee calf measures about 80 cm (30 in.).

3. The calf can be born either head- or tail-first.

4. At birth, a calf has fetal folds in its skin which lasts for several weeks.

Care of Young

1. The newborn calf is capable of swimming to the surface on its own for its first breath.


















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Manatee calves swim to the surface after birth fortheir first breath of air.

2. Calves vocalize at or soon after birth. This auditory form of communication is an important part of themother-calf bonding process.

3. The calf begins to nurse within a few hours after birth by suckling from teats under the pectoralflippers. Calves nurse under water.

Manatee calves begin nursing a few hours after birth. The mother'smammary gland is located under the front flippers.

4. Manatee milk contains mostly water with 20% solids, 7% protein, and 13% fat (lipids).

5. Calves begin nibbling on plants within a few weeks of birth.

6. Although it may be weaned by the end of its first year, the calf remains close to its mother for up to twoyears. It is dependent on its mother not only for nutrition, but also for learning about feeding andresting areas, travel routes, and warm water refuges.

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Senses

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Appendix


Bibliography

ManateeLongevity & Causes of Death

Longevity

1. Manatees probably live a maximum of about 50 to 60 years.

Manatees probably live a maximum of about 50 to 60 years.

Aging

1. A consequence of manatee tooth replacement is that scientists cannot use the teeth to age individualmanatees, a procedure commonly used for many other species of marine mammals. Scientists insteaduse a method of aging manatees based on studying growth patterns that develop on ear bones.

Predators

1. Although predation has not been documented, scientists believe sharks, alligators, or crocodiles mayoccasionally attack West Indian manatees.

2. Crocodiles and sharks sometimes prey on West African manatees.

3. Jaguars, caimans, and sharks prey on Amazonian manatees.

Causes of Death

1. Natural causes.

Manatees are very susceptible to cold weather. It is not unusual for many to die during extremelycold weather. In 1996, at least 17 died due to cold related illnesses. During an exceptionally harshwinter in 1990, 46 manatees succumbed to the bad weather.

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Power plants create warm-water discharges that aresought by manatees.

Amazonian manatees become concentrated in confined areas when lakes dry up. They aresusceptible to starvation and predation.

As in any animal population, a variety of diseases and parasites can be responsible for manateedeaths.

In early 1996, about 150 manatees died in southwest Florida. Scientists determined the massmortality was caused by a red tide organism called Gymnodinium breve which produces toxins. Themanatees died after ingesting or breathing in the toxins which attacked their organs (Luoma, 1996).

2. Human-related causes.

Watercraft accidents.

More than 770,000 boats were registered in Florida for the 1995-96 season.

Manatees are sometimes difficult for boaters to see in the water.

Due to their dark color and because they are slow swimmers, manatees are difficult tosee in the water. At least 20% to 22% of manatee deaths in Florida occur from watercraftaccidents yearly. Collisions with boats and barges is the largest human-related factorcausing manatee deaths in Florida. (U. S. Fish and Wildlife Service, 1995).

Although the engine propellers are dangerous, collisions with boats cause the mostwatercraft related deaths. In 1995, 12 manatees expired from propeller injuries while 25died from impact wounds. Collisions with boats cause life-threatening internal injuriesthat are often hard to locate and treat.

Only 5% of 400 manatees surveyed had head injuries from boating accidents while morethan 70% had wounds on their upper backs. This suggests that manatees try to diveaway from boats but cannot escape in time to avoid injuries (Bloch, 1993).



Manatees become entangled in fishing and crab trap lines,sometime resulting in serious wounds.

This manatee's flipper became entangled in a crabtrap and will require medical treatment.

Flood gates and navigation locks.

As manatees swim upstream, they may encounter flood gates and navigation locks.When flood gates are left partially open, manatees sometimes swim through them. Theymay become trapped in the water current from the upstream side and drown. Theremote-controlled flood gates have also crushed manatees.

Entrapment in flood control gates and navigation locks regularly kill manatees and is thesecond leading human factor for manatee deaths. A record 16 manatees died from thesedevices in 1994. From 1976 to 2000, 166 manatees were confirmed dead from floodgates and navigational locks in the state of Florida.

To help the problem, engineers are installing pressure-sensitivemechanisms on flood gates known to cause the most manatee deaths. Thecost of each sensor is about $50,000 (U. S. Fish and Wildlife Service,1995).

Poaching and vandalism.

In spite of the fact that manatees are legally protected, poachers andvandals are also responsible for manatee deaths. In some areas manateesare hunted for food. Others are victims of harassment.

Accidental entanglement and pollution.

Florida manatees have been found with fishing lines or crab trap lineswrapped around them. These materials can wrap tightly around themanatee's flippers, causing serious infections, amputations, or death.

In a survey of 439 manatee carcasses, 14.4% had debris in their stomach.

Habitat destruction.

Since the 1950s destruction of the natural habitats of many coastalanimals is accelerating at an alarming rate. Much of the suitable manateehabitat in Florida (seagrass beds, salt marshes, and mangrove areas) hasbeen destroyed.

The human population in Florida increases by nearly 1,000 people daily.

About 250,000 acres of forests are lost every year in Florida and roughlyone-fourth of the state remains semi-natural.



3. Death increases.

All total, a record 415 manatees died in 1996. Even when the 150 manatees that died from the redtide outbreak were subtracted, it was still the worst year for manatee deaths ever recorded inFlorida. The total mortality rate for Florida manatees has risen an average of 5.3% every year since1976.

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Adaptations

Communication

Behavior


Reproduction



→ Conservation &Research

Appendix


Bibliography

ManateeConservation & Research

Endangered Species

1. All four species of sirenians are endangered or threatened.

2. The Florida manatee is one of the most endangered marine mammals in the United States.

Manatees are endangered in the United States.

Legal Protection

1. All species of sirenians are protected to some extent by national or local acts in every country theyinhabit.

2. Federal and state laws have been passed that protect Florida manatees.

Federal laws prohibit hunting, capturing, killing, or harassing these animals. These laws include theMarine Mammal Protection Act of 1972 and the Endangered Species Act of 1973. Penalties forbreaking these federal laws could include a year in prison and a fine up to $20,000.

The Florida Manatee Sanctuary Act of 1978 is state legislation that allows the establishment ofmanatee sanctuaries in Florida.

3. West African manatees are protected under Class A of the African Convention of Nature and NaturalResources, signed by 38 African countries.

4. Amazonian manatee hunting has been prohibited since 1973.

5. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is aninternational treaty developed in 1973 to regulate trade of wildlife items. All species of sirenians areprotected by this treaty.

Marine Zoological Parks

1. Marine zoological parks such as SeaWorld Florida and SeaWorld California help conserve manatees.SeaWorld is authorized to rescue and rehabilitate ill, injured, or orphaned manatees.

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SeaWorld is authorized to rescue and rehabilitate ill,injured, and orphaned manatees.

2. The first priority of the manatee rescue and rehabilitation program is to return healthy manatees totheir natural habitat. SeaWorld Florida has successfully rescued and released more than 80 manateesas of December 2000. SeaWorld Florida rescued 13 manatees in 2000 and released six.

The first priority of the manatee rescue and rehabilitation programis to return healthy manatees to their natural habitat.

3. In the controlled environment of a marine zoological park, scientists can study aspects of manateebiology that are difficult or impossible to study in the wild.

Having manatees at marine zoological parks provide the opportunity for the public to learn aboutthese rare animals.

Having manatees at marine zoological parks provides the opportunityfor the public to learn about these rare animals.

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Senses

Adaptations

Communication

Behavior


Reproduction




→ Appendix


Bibliography

ManateeAppendix

Table: Florida Manatee Census Counts

DATE OF SURVEY TOTAL COUNT

Jan. 23-24, 1991 1,267

Feb. 17-18, 1991 1,465

Jan. 17-18, 1992 1,856

Jan. 21-22, 1995 1,443

Feb. 6-7, 1995 1,822

Jan. 9-10, 1996 2,274

Feb. 18-19, 1996 2,639

Jan. 19-20, 1997 2,229

Feb. 13, 1997 1,709

Jan. 29-30, 1998 2,022

Jan. 6, 1999 1,873

Feb. 23, 1999 2,034

March 6, 1999 2,353

Jan. 16, 2000 1,629

Jan. 27, 2000 2,222

Jan. 2001 3,276

March 2002 1,796

Table: Manatee Deaths By Year/Category

YEAR WTRCRFT LCK/GT OTHER NAT UNKNWN PERINTL* TOTAL

1976 10 3 0 1 32 16 (1) 62

1977 13 6 5 1 79 11 (1) 115

1978 21 9 1 3 40 10 84

1979 22 8 8 4 24 12 (3) 78

1980 15 8 2 6 19 15 (1) 65

1981 23 2 4 9 65 14 (1) 117

1982 19 3 2 40 37 16 (1) 117

1983 15 7 5 6 30 18 81

1984 33 3 1 24 41 28 (1) 130

1985 35 3 3 20 39 23 123

1986 31 3 1 13 47 30 (2) 125

1987 37 5 3 15 23 34 (3) 117

Appendix

















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1988 43 7 3 22 25 34 (1) 134

1989 50 3 4 32 45 42 (2) 176

1990 49 3 4 71 41 46 214

1991 52 9 6 15 39 54 (1) 175

1992 38 5 6 21 49 48 167

1993 34 6 7 24 36 40 (1) 147

1994 50 16 5 37 40 46 194

1995 43 8 5 35 55 57 203

1996 59 10 1 118 164 64 (1) 416

1997 52 8 8 46 67 65 (4) 246

1998 66 9 6 23 85 54 (1) 243

1999 83 15 7 43 69 57 (1) 274

2000 78 7 9 51 70 58 273

2001 81 1 7 33 108 33 325

TOTAL 1052 167 113 713 1369 925 (26) 4401

Manatee Mortality Database

The manatee mortality database is now available on the web site of the Florida Fish & Wildlife ConservationCommission's Florida Marine Research Institute (FMRI). In addition to the monthly mortality tables alreadyavailable on the web site, the new database enables the user to search for manatee mortality information bycounty, cause of death and date from 1974 through 2001. Two report formats are available: A 'summary' reportwhich lists the search results in a numbers-only table, and an 'individual' report which provides more detailedinformation such as sex, size, region and cause of death. You can find the new manatee mortality search on theFMRI web site at http://www.floridamarine.org/manatees/.

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Appendix

→ Books For YoungReaders

Bibliography

ManateeBooks For Young Readers

Book List

Amazing Animals of the Sea. Washington, D.C.: National Geographic Society, 1981.

Crump, Donald, ed. National Geographic Book of Mammals. Vol. II. Washington, D.C.: National GeographicSociety, 1981.

Goff Clark, Margaret. The Vanishing Manatee. New York: Cobblehill Books, 1990.

Gordon, Esther and Bernard. Once There Was a Giant Sea Cow. New York: Henry Z. Walck, Inc. 1977.

Kuzmier, Kerrie and Jennifer McCann. Manatees and Dugongs. Washington, D.C.: Center for MarineConservation, 1990.

Parham, Donna. To the Rescue! San Diego: Seaworld Education Department Publications, 2001.

Sibbald, Jean H. The Manatee. Minneapolis, Minnesota: Dillon Press, Inc., 1990.

Unterbrink, Mary. Manatees Gentle Giants in Peril. St. Petersburg, Florida: Great Outdoors Publishing Co.,Inc., 1984.

Wlodarski, Loran. The Story of Manatees. Siren’s Song. Orlando: SeaWorld Education DepartmentPublications, 2003.

Wlodarski, Loran. Wild Careers! Working With Animals. Orlando: SeaWorld Education DepartmentPublications, 2003.

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Senses

Adaptations

Communication

Behavior


Reproduction




Appendix


→ Bibliography

ManateeBibliography

References

Arseniev, V.A. Atlas of Marine Mammals. Neptune City: T. F. H. Publishing, Inc., 1986.

Blashfield, Jean F. Awesome Almanac Florida. New York: B&B Publishing, 1994.

Blank, Joan. Key Biscayne. Tampa: Pineapple Press, 1996.

Bloch, Nini. "The Last Mermaids." Earthwatch 12(7), Nov.-Dec. 1993, pp. 16-23.

Chapman, J. A. and G. A. Feldhamer. Wild Mammals of North America. Baltimore: The Johns HopkinsUniversity Press of Florida, 1993.

Dietz, Tim. The Call of the Siren. Golden: Fulcrum Publishing, 1992.

Griebel, Ulrike and Axel Schmid. "Color Vision in the Manatee." Vision 13(17), 1996, pp. 2747-2757.

Harrison, R. J. Functional Anatomy of Marine Mammals. New York: Academic Press, 1974.

Luoma, Jon R. "What's Killing the Manatees?" Audubon 98(4), July-August 1996, pp. 18-22.

Nowak, R. M. and J. L. Paradiso. Walker's Mammals of the World. Baltimore: The Johns Hopkins UniversityPress, 1999.

O'Shea, Thomas J. "Manatees." Scientific American 271(1), July 1994, pp. 66-72.

O'Shea, Thomas J., B. B. Ackerman and H. F. Percival. Population Biology of the Florida Manatee.Washington D.C.: Publishing Unit, U.S. Fish and Wildlife Service, 1995.

Reynolds, John E. III and Daniel K. Odell. Manatees and Dugongs. New York: Facts On File, Inc., 1991.

Mammals of the Sea. Rome: Food and Agriculture Organization of the United Nations, Vol. II, 1979.

Ridgeway, Sam H. and Sir Richard Harrison. Handbook of Marine Mammals. Orlando: Acedemic Press, Inc.,1985.

Savage, R. J. G., Daryl P. Domning and J. G. M. Thewissen. "Fossil Sirenia of the West Atlantic and CaribbeanRegion." Journal of Vertebrate Paleontology 14(3), September 1994.

Stejneger, Leonard. Georg Wilhelm Steller. Cambridge: Cambridge Press, 1936.

U.S. Fish and Wildlife Service. Florida Manatee Recovery Plan Third Revision. Atlanta: U.S. Fish and WildlifeService Press, 2000.

Van Meter, Victoria Brook. The West Indian Manatee in Florida. Florida Power and Light CompanyPublishings, 1989.

Bibliography

















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Scientific Classification€¦ · Manatees and dugongs are found in warm waters around the world....

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