Florida Manatee Facts | Anatomy, Diet, Habitat, Behavior

The Florida manatee (Trichechus manatus latirostris) is one of the largest coastal mammals in North America. It is one of the two subspecies of West Indian manatee. The manatee is thought to occur along the Florida waters. Florida manatees are likely to cover long distances. Sea cow is the other name given to Florida manatee. According to 2010 census the total population of Florida manatees hit record numbers of up to 6,063. In Florida, the Florida Manatee Sanctuary Act has been put in place to give protection to the Florida manatees.

Florida Manatee Facts

Anatomy

• The adult manatee averages 11.5 feet (3.5 m) in the overall length and weighs up to 2,200 pounds (1,000 kg). Some of them may be as large as 3,500 pounds (1,588 kg).
• Like typical manatees, the Florida manatee is distinguished by its heavy bulky body. The manatee’s skin is greyish brown with tiny hairs on it. At times the body is covered with algae precisely because the animal feeds on underwater plants.
• They have long elongated snout and whiskers. Florida manatee’s eyes are small as compared to their size.
• They are thought to possess good eyesight and can see objects from distances.
• Manatees lack external ears they can certainly hear.
• They have got series of different calls including squeaks, grunts, groans, squeals, and low chirps.
• Thanks to the manatee’s nostrils that do not allow water to enter while the animal is submerged.
• Florida manatees are able to be remained submerge for up to 15 minutes.

See also: Manatee Facts For Kids

Range & Habitat

• Florida manatees are the native species of the southeastern United States, typically breeding on the inland and coastal waters of peninsular Florida.
• Some of the isolated population is also found in the southeastern Georgia.
• In summer many Florida manatees swim along the Atlantic and Gulf Coast to go as far north as Rhode Island. Both Rio Grande in Texas and Bahamas host very manatees.
• Florida manatees seem to prefer warm waters and as such they don’t leave Florida waters from April to November.
• Manatee’s range also includes San Carlos Bay, Estero Bay, Matlacha Pass, Charlotte Harbor, and the Lake Okeechobee.
• The Florida manatee makes home in a wide variety of habitats such as brackish water, coastal and riverine habitats as well as estuarine and spring habitats.

Behavior

• Florida manatees are semi social as they travel in small groups but in winter the size of the group increases. They are believed to make relatively quick and long water migrations.
• There are no leaders in a group nor do they claim any territory.
• Scientists believe that manatees are quite intelligent animals. They are not as lazy as they look; manatees often involve each other by playing, chasing, nuzzling, and touching.
• They are more likely to swim in saline waters as compared to fresh water.
• In spring, manatees leave the Florida waters and begin moving toward the Atlantic coastline. Many manatees are often observed in the mid-Atlantic waters of the New England states.
• Florida manatees are thought to choose their habitats according to their feeding requirements. For instance the warm waters of the southern Florida as well as St. Johns River are abundant in floating vegetation.
• They will also swim in the freshwater habitats including lagoons, rivers, and canals.
• During cold days of winter, manatees leave warmer waters to get to the vegetated areas.
• Each group consists of 50 manatees.
• Florida manatees can cruise at an average speed of about 2 – 6 miles per hour but they are able to swim as fast as 15 mph in short bursts.
• In some countries such as Guyana, Florida manatees are bred in captivity in order to seek help to clear out vegetation-choked waterways and canals.
• They will produce sounds with the frequencies in the 3–10 kHz range.

Feeding Ecology & Diet

• Manatees are the only herbivorous marine mammals. They rely on underwater aquatic vegetation including algae.
• Florida manatees eat up to 20% of their entire body weight. They spend many hours looking for food and it happens almost every day.
• The foraging activity increases in the late fall during which it spends around 7 hours each day. However in the early spring manatees spend around 3.2 hours each day on foraging.
• Manatees are opportunistic feeders and they are likely to consume as much as 60 species of aquatic vegetation.
• It is thought to supplement its diet with some invertebrates and small fish. They don’t really go for the invertebrates it’s just that while eating plants the insects attached to it are also consumed.
• Prominent among the aquatic plants are manatee grass, Cuban shoal grass, and turtle grass. The waters of the South Florida offer vegetation such as this. Florida manatee’s diet also consists of shoreline vegetation including cordgrass.
• Manatees also eat leaves of overhanging mangroves.
• They prefer to feed on submerged vegetation but if it is scarce then the manatee goes for the floating vegetation. The northeastern population relies more on the floating vegetation because here the habitat rarely offers the submerged vegetation.
• Among floating vegetation manatees choose alligator weed and warm water fern.
• The freshwater vegetation includes many species of Myriophyllum and hydrilla.

See also: What Do Manatees Eat?

Reproductive Biology

• Female manatees are likely to reach maturity at 2.5 – 6.0 years while males become mature when they reach 2 – 11 years age.
• Calves are thought to stay with the mother for 1 year. Nearly 70% of the calves stay with their mother and they remain so throughout the winter season.
• The breeding interval is 2 – 3 years. The female gives birth to only one calf though twins are also born.
• The gestation period lasts about 1 year (Daniel Hartman, 1979)
• The average weight of calves is about 60 – 80 pounds (27 – 36 kg) at birth. They have body length measuring up to 4 feet (1.2 m).
• Manatee’s calves show dark-colored coat but it lightens after few days.
• The lactation period lasts about 1.5 years but it depends on the conditions in the wild and in captivity.
• The young become independent in just one year. They may start feeding on vegetation before they come of age.
• The average lifespan of Florida manatees is 30 years but one such species is in captivity in Miami Aquarium. It was born in 1948 and is still alive. This shows that the captive manatee lives a much longer life. It is believed to live 60 – 70 years.
• Humans are possibly the only predators of Florida manatees. A few sharks also prey on manatees.

References

O’Shea, T. J., B. B. Ackerman, and H. F. Percival. Population Biology of the Florida Manatee. Washington, DC: U.S. Department of the Interior, National Biological Service, 1995.

O’Shea, T. J. “Manatees.” Scientific American 271, no. 1 (1994): 50–56.

Hartman, D. S. Ecology and Behavior of the Manatee (Trichechus manatus) in Florida. Lawrence, KS: American Society of Mammalogists, 1979.