Manatees at Blue Spring State Park. Photo by D. Sillman
(Click on the following link to listen to an audio version of this blog … Florida 5 Manatees
It’s hard to say why certain animals are compelling and charismatic. Seeing a moose cutting across your hiking trail, seeing a cougar staring at you from a high rock overhead, catching a glimpse of a wolf silently slipping back into the shadows of a forest, seeing a giant manta ray breeching next to your small boat as you run from island to island in the Galapagos: these moments are full of wonder and excitement! But, some animals exude their charisma by just sitting there and doing nothing: an American alligator sleeping next to a bike path in the Everglades, an American bison bull eyes half-closed standing like a statue next to the road in Yellowstone, or a few dozen manatees quietly sleeping as still as shadows in a warm-water river in Florida.
You just can’t your eyes off of them!
Montel (a green sea turtle). Photo by The Turtle Hospital
When we went to the Florida Keys in December 2022, there were three animals that I wanted to see: a sea turtle (I hadn’t narrowed my choice down to a species, I just wanted to see a big turtle!), an American alligator, and a manatee. By going to the Turtle Hospital in Marathon, Florida (our beach condo was right next to it!) I got two hours of sea turtle experience (and even, as a Christmas present from my daughter and son-in-law, adopted Montel, a “permanent resident” green sea turtle at the hospital (her injuries that lead to her hospitalization were too servere to allow her release back into the wild)). When we drove up to the Everglades I got several up-close-and-personal contacts with substantial American alligators who were napping on the side of the trail where we were walking.
But, sadly, no manatees: not in the sea grass beds just offshore from our beach house, not even on our spectacular kayak tour through the mangrove swamps on the Gulf side of Marathon Key. Returning to Florida this winter, then, a manatee sighting was at the top of our bucket-list!
I mentioned this to my old Pennsylvania, biking and guitar-playing friend, Don, who spends the winter in Osteen, Florida near Sanford with his wife, Andrea. Don said, “we know where the manatee are! Just come on down!” So, Deborah and I rented a car and drove two hours south from Amelia Island into the increasingly warmer and increasingly more humid Florida.
Florida sandhiil cranes. Photo by D. Wicks
When we arrived at Don and Andrea’s we were greeted by their resident, non-migratory, sandhill cranes ( the Florida subspecies of the sandhill crane, Antigone canadensis pratensis). The greeting bird walked right up to us, gave us a good look-over and then slowly walked off in search of something more interesting. I have mentioned these Florida cranes before (see Signs of Winter 13, February 25, 2021). Our manatee viewing was set for the next morning, so, we drove over to New Smyrna Beach down on the coast, had a great lunch at a dockside restaurant and then drove just south to Cape Canaveral National Seashore to see the sea turtle nests.
Sea turtles really utilize the protected spaces of this seashore! In 2023 alone, just under 17,000 sea turtle nests were established here. Over 11,000 of them were green turtle (Chelonia mydas) nests and almost 6,000 were loggerhead turtle (Caretta caretta) nests. There were also a couple of dozen leatherback turtle (Dermochelys coriacea) nests and one Kemps Ridely turtle (Lepidochely kempii) nest. On average a sea turtle’s nest contains 110 eggs, so these Cape Canaveral National Seashore nests probably represented over a million and a half potential sea turtles! Most of the eggs are laid in the late spring or early summer and hatch, in batches, after 60 days of incubation.
Unfortunately, we were not able to get into the turtle nesting area. Park rangers, clad in bullet-proof vests and carrying really scary-looking, automatic weapons, blocked off the entry road. They were not in a mood to talk or explain why we weren’t allowed to go into the reserve. They simply said that the parking areas were all full, so no one could drive in.
Armadillo. Photo by Vlad Lazarenko. Wikimedia Commons
We went for a quick walk on the northern-most and still open beach of the reserve and when we came out, the roadblock and the armed guards had moved on out to just outside the entrance gate. So we turned into the reserve and drove down the main road. There were people parked along the various beaches (including the nude beach which was, yep, nude!). There was no sign of overcrowding or any other reason for the road closure. No big drug busts, criminal apprehensions , no political visitors that needed to be protected, no secret rocket launches or maneuvers down on the Space Center to the south. It made no sense. The information kiosks and tourist centers were all closed up, and there was nothing to see but some armadillos (Dasypus novemcinctus) running down along the roadside or laying mushed on the concrete. We drove out and waved at the guards. Strange afternoon!
The next morning we were up early to make the drive over to Blue Spring State Park. For most of the year, manatees are very solitary animals, but in the winter they need to seek out warm water (like warm springs feeding coastal rivers or power plant outflows). They then gather in large numbers at suitable sites. Blue Spring is a natural, warm water spring (average temperature is 73 degrees F) that flows into the St. John’s River. The warmed section of the river is a much-used refuge for manatees especially on cool winter nights and early mornings.
Manatees. Phot by D. Sillman
We walked from the parking area down to the paved riverbank, and looked for manatees. There were supposed to be 60 manatees gathered in the river this morning. At first I didn’t see anything in the water, but, then, as my eyes got used to the sun-glare off the water’s surface and the rippling patterns of the intensely clear river water, I saw them! Silent, gray-brown shapes floating just above the river bottom. They were basking in the warm water and barely moving. They were awesome!
Manatees are huge aquatic mammals! They can be over 13 feet long and weigh up to 3500 pounds (although 1300 pounds is a reasonable average). They are herbivores that eat over 60 types of plants. They regularly spend 7 or 8 hours a day grazing and eat 10 to 15% of their body weight each day. They have prehensile lips and dexterous forelimb flippers that they can use to gather and manipulate vegetation. Their molars (their only type of teeth) grind up the vegetative materials and pass them along into their relative simple, but very elongated digestive system (they have 45 m of intestines!). They have six molars on each jaw and regularly grind down and lose their front teeth, replacing them with new ones in the back. Unlike cows, they don’t have a partitioned stomach to facilitate the breakdown of all of the cellulose they ingest, but they do have, like a horse, a large cecum which acts as a digestion chamber.
Manatees. Photo by D. Sillman
Manatees ( this Florida species is Trichechus manatus, the “West Indian manatee”) live in the shallow, marshy coastal waters and rivers all through the Caribbean and the Gulf of Mexico. Other species of manatee are found in the Amazon and South America and also in West Africa. The Florida manatee occasionally travels up to surprisingly northern sites on the Atlantic Coast (they have been seen off New York City, Rhode Island and even Cape Cod!), but most typically they seldom stray much further north than Georgia. Manatees have surprisingly little subcutaneous fat and must stay in warm water to maintain their thermal equilibria.
According to the U.S. Fish and Wildlife Service, there are 6,300 manatees in Florida. Manatees have recently been removed from the Endangered Species List even though their mortality rates have been skyrocketing! In 2021 , 1100 Florida manatees died! In 2022, 800 Florida manatees died, and in 2023, 556 manatees died. Hurricanes, red tides, pollution, cold stress and starvation are typical causes of manatee deaths. Collisions with boats are often presented as a major cause of mortality, but typically there are “only” 100 manatee deaths a year due to strikes by boats. Most experts agree that starvation and a syndrome called “acute lethal gut shock” (caused by manatees eating less nutritious macro-algae rather than sea grass and other true plants) are the main causes of the exponential rise in manatee mortality.
Sea grass beds and other natural, coastal vegetation are being decimated primarily by human-generated pollution (including sewage and septic system drainage and agricultural field run off). Glyphosate herbicide residues (which are found at very high levels in almost all of Florida’s surface water) are especially toxic to sea grasses and other natural, coastal vegetation.
Manatee rescue. Photo by USFWS, Public Domain
We watched the manatees float in their groups of 10 or 12 for over an hour. Blue Springs is both a refuge for manatees and also a rehabilitation location. Just the week before, several manatees were brought to Blue Spring from a hospital facility and carefully released into the warm water. The rehabilitating manatees are clearly marked, and as they continue to heal they will be able to freely swim out into the coastal waters.
Great thanks to Don and Andrea for a wonderful manatee experience!