The Florida Manatee
This time of year, our Florida manatees resort to the warmer waters of the springs to survive the cold waters of winter. One of the largest winter sanctuaries for this magnificent animal is Blue Springs State Park. Here you can view the manatee in it’s natural habitat, with a bird’s eye view from the boardwalk that runs along the spring, or from the St Johns River, via kayak, as they come and go into the river. We offer informative guided kayak tours to the park. These tours not only brings awareness of the Florida manatee, but also involves other wildlife, such as bald eagles, hawks, alligators and several birds of the marsh. The link to this tour is below.
Here are a few facts about our magnificent Florida manatee. The West Indian Manatee is divided into two subspecies, the Florida manatee and the Antillean or Caribbean manatee. The average West Indian manatee is approximately (8.9–11.5 ft) long and weighs (440–1,320 lb), with females usually larger than males. The Florida manatee can be found all over in the warm waters of St Augustine in the summer. The West Indian manatee is surprisingly agile in water, and individuals have been seen doing rolls, somersaults, and even swimming upside-down. Manatees are not territorial and do not have complex predator avoidance behavior, as they have evolved in areas without natural predators. The common predators of marine mammals, such as orcas and large sharks, are rarely, if ever found in habitats inhabited by this species, however the American alligator doesn’t bother them as well, and no one can really explain why? Just a nature thing?
Manatees have sensitive tactile hairs that cover their bodies and face called vibrissae. Each individual hair is a vibrissal apparatus known as a follicle-sinus complex (FSC). Vibrissae are blood filled sinuses bound by a dense connective tissue capsule with sensitive nerve endings that provides feedback to the manatee. Usually vibrissae are found on the facial regions of land critters and are called whiskers. Manatees however, have vibrissae all over their body. The vibrissae on their facial region are roughly 30 times denser than the vibrissae on the rest of their body. Their mouth consists of very mobile prehensile lips which are used for grasping food. The vibrissae on these lips are turned outward during grasping and are used in locating vegetation. The vibrissa on their bodies, not only help them find food, but also help in their navigation of turbid waters.
Manatees are herbivores, meaning they feed on mostly plants, although they do dine on some small fish and invertebrates ( little spineless creatures). There are about 60 plant species which the Florida manatee chow on, which include sea grasses as their major food source. Because manatees feed on abrasive plants, their molars are often worn down and are continually replaced throughout their life, hence called “marching molars”.
The Florida manatee has a high casualty rate due to thermal shock from cold water temperatures. Their digestive tract shuts down if they linger too long in water temperatures below 68 degrees. Many manatee deaths are caused by motorized boats, mostly from their propellers. The state and various private organizations have done a good job bringing public awareness to this fact.
Although the Florida manatee is mostly a solitary creature, they do form mating herds while the female is in estrus. Most females first breed successfully between ages of seven and nine; they are, however, capable of reproduction as early as age four. Most males reach sexually maturity by the time they are three or four. The gestation period is 12 to 14 months. As the norm, one calf is born, although on rare occasions two have been recorded. We saw a mother with two calfs last year on one of our tours to Blue Springs. (see pic above) It was a rare and special treat! The young are born with molars, within the first three weeks of birth, allowing them to consume seagrass, although they will still nurse from there mother. On average, manatees that survive to adulthood will have between five and seven offspring between the ages of 20 and 26. When a calf is born, it usually weighs between 60 and 70 pounds and is between 4.0 and 4.5 feet long. The family unit consists of mother and calf, which remain together for up to two years. Males aggregate in mating herds around a female when she is ready to mate, however they are dead beat dad’s and contribute no parental care to the calf.
Fun Fact ~ The name manatí comes from the Taíno, a pre-Columbian people of the Caribbean, meaning “breast”