1. Manatees (and Dugongs)
Order Sirenia
Manatees
(and Dugongs)

2. Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Sirenia
Includes 3 species of manatees and one species of dugong
We will focus on the manatees

3. Habitat and Distribution
Found in warm tropical and subtropical waters
West Indian and West African manatees inhabit rivers, bays, canals, estuaries, and coastal areas rich in seagrass and other vegetation
They can live in fresh, salt, or brackish water and can freely move back and forth
Found in waters over 3 ft deep and water temps above 65˚F
Amazonian manatee is strictly freshwater and require water temps of 77-86˚F

5. Physical Characteristics - Size
West Indian and West African manatees
Avg 10 ft and weigh lbs
Can reach up to 13 ft and 3650 lbs)
Amazonian manatees
Avg 9 ft and 1000 lbs

6. Physical Characteristics
Body shape: streamlined
Wide middle section, narrow ends
Coloration
Gray, though they may appear brown-gray
Algae may grow on their skin since they are so slow moving

8. Physical Characteristics – Head
Pectoral flippers have five digits will nails on 3-4 of these digits
No hind limbs
Ears are tiny openings on side of head
Nostrils lie at the end of the snout on the upper surface and close automatically when under water

10. Physical Characteristics – Head
Vibrissae are sensitive
Small eyes – less than 1 inch in diameter
Have molars located in the back of the mouth
As the front teeth are worn down, more molars grow at the back and push the other teeth forward

11. Physical Characteristics
Tail is evenly rounded and forms a paddle shape
Dugongs have a more dolphin-like tale
Swim by moving its large tail up and down
Sparse hairs are scattered all of the body, with the largest concentration around the snout area

13. Senses Hearing Eyesight Not well studied
Important sense for communication between mother and calf
Eyesight
Well-developed
Can detect objects from tens of meters away
Nictitating membrane acts as an extra eyelid for protection

14. Senses Tactile Taste and Smell Touch is important for manatees
Body contact is common between mother and calf
Taste and Smell
Hasn’t been well studied
Have taste buds so most likely taste
Studies have shown they do avoid certain plants
Have some sense of smell
Scientists believe smell is used to determine if a female is in “heat” or estrus

15. Adaptations Swimming Diving Quite agile Maneuver well under water
Can swim up to 15mph for short bursts, but usually cruise at 2-6mph
Diving
Can dive down to over 30 ft but typically stay within top 10 ft
Can stay submerged up to 20 minutes, but avg 2-3 minutes per dive

16. Communication Sound production
Emit sounds underwater, such as chirps, whistles, or squeaks
Make sounds when they are frightened, sexually aroused, or interacting with each other
Important for mother-calf relationship
Mothers can hear calves from over 200ft away
Also communicate through sights, taste, touch, and smell

17. Behavior Nonaggressive, nonterritorial
Spend most of their time feeding and resting
Spend additional time traveling, socializing, interacting with others, and investigating objects

19. Social Behavior Semi-social
Groups form and disperse casually
Groups tend to be temporary and vary regarding sex, number, and age
Tend to congregate in warm water during the winter
Have been seen participating in semi- organized, playful activities like bodysurfing and follow-the-leader

20. Diet and Eating Habits Herbivorous
Feed on a wide variety of submerged, emergent, floating, and shoreline vegetation
Rarely they have been seen eating fish and clams
Consume about 4-9% of their body weight on a daily basis
Feed of the ocean bottom, in the water column, and at the surface, and sometimes they will partially haul out to feed on shoreline vegetation

21. Reproduction Sexual maturity Mating Activity
Males (Bulls) mature by 9-10 yrs
Females (Cows) mature as young as 3 yrs
Mating Activity
Cows will mate with several bulls
Males compete for females – push others

22. Birth Gestation is approximately 12 months
Breed year round, but cows seem to have a higher birth rate during the spring and summer
Females produce a single calf about every 2-5 yrs
At birth, calf is ft long and weighs lbs

23. Care of Young
Calf is able to swim to the surface on its own for its first breath
Calves vocalize at birth – important for bonding between mother and calf
Calf begins nursing shortly after birth and begin eating vegetation within a few weeks
Calf is weaned by 1 yr but remains with mother for up to 2 yrs

25. Causes of Death Live an avg of 50-60 yrs
Predation of manatees is uncommon
Have been attacked by sharks, alligators, and crocodiles though
Natural causes:
Cold weather increases illnesses
Starvation and predation
Diseases and parasites
Red Tides

26. Causes of Death Human-related causes Watercraft accidents
Hunted for food
Victims to harassment
Accidental entanglement in fishing nets and other fishing gear
Pollution
Habitat destruction

28. Conservation and Research
All four sirenians are endangered
All are protected by national acts in every country they are found
US Federal laws prohibit hunting, capturing, killing, or harassing these animals
Florida Manatee Sanctuary Act of allows the establishment of manatee sanctuaries if Florida

29. Conservation and Research
Marine Zoological Parks
Many are authorized to rescue and rehabilitate ill, injured, or orphaned manatees
Main goal is to rehabilitate and then return healthy manatees to the wild
If they believe the individual will not survive in the wild, they will house the animal for educational purposes
Play a huge role in education of the public