Continuing my discussion of Caty's and my trip to Everglades National Park, let's talk about Crocodiles and Alligators. Before I visited the Everglades in 2014, I didn't even realize Crocodiles lived in North America. But, on that trip, I learned about them on the Flamingo boat tour and saw a few little ones. This time, we saw an adult almost as soon as we arrived at the Flamingo Marina.
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| Flamingo Marina: American Crocodile |
Populations of American Crocodiles occur near tropical waters from the Atlantic and Pacific coasts of southern Mexico to South America. They live on many of the Caribbean islands such as Cuba, Jamaica, Hispaniola and Grand Cayman. Within the U.S., the American Crocodile's distribution is limited to Puerto Rico and the southern half of Florida; at least two have been found as far north as the Tampa Bay area. The current U.S. population, estimated at 2,000, represents a significant recovery from a few hundred in the 1970s.
American Crocodiles live in rivers, but prefer some level of salinity, resulting in the their tendency to congregate in brackish lakes, mangrove swamps, lagoons, cays and small islands.
The American Crocodile is one of the larger Crocodile species. Males can reach lengths 20 ft., weighing up to a ton. Females are smaller; rarely exceeding 12 ft. The large one we saw was probably 8-12 ft. long.
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| Flamingo Marina: American Crocodile |
It swam around near where the tour boat was moored and then parked itself on the boat ramp. I would certainly be careful about launching a boat there! But, actually, despite their large size, American Crocodiles are not very aggressive and attacks on humans are rare. They eat mainly fish, reptiles, birds and small mammals and, on occasion, large mammals such as Deer and Cattle.
In 2014, an escaped Nile Crocodile was captured alive in Everglades National Park after a two-year hunt. The African species is much more aggressive than the smaller American crocodile.
American Crocodiles have a V-shaped snout, compared to other large Crocodiles and, especially to Alligators, which have a wide snout. Another feature that distinguishes them from Alligators is large teeth that project up from their lower jaws. Alligators reveal only upper teeth projecting down when their mouths are closed.
In addition to the large adult, we also saw five baby Crocs, ranging from a very small one ...
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| Flamingo boat tour, Buttonwood Canal: baby American Crocodile #1 |
... to progressively larger ones. Our tour guide was particularly adept at spotting baby Crocs, which, despite their prominence in the photos, were very difficult to pick out.
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| Flamingo boat tour, Buttonwood Canal: baby American Crocodile #2 |
Although adults are grayish-green with white or yellow undersides, juveniles are lighter with dark cross-banding on the tail and back. Their eyes are freakish, appearing to have a cross in the middle. That's partially because of the nictitating membranes that cover them. Their nostrils, eyes and ears are on the top of the head, so the rest of the body can be concealed underwater for surprise attacks. But, they seem to enjoy sunning themselves.
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| Flamingo boat tour, Buttonwood Canal: baby American Crocodile #3 |
Like all Crocodilians, the American Crocodile is a quadruped, with four short, stocky legs, a long, powerful tail and a scaly hide with rows of spikes running down its back and turning at an angle when it reaches the tail. They normally crawl on their bellies, but can "high walk" and charge at up to nearly 10 mph. They can swim at as much as 20 mph by moving their bodies and tails in a sinuous fashion, but they cannot sustain this speed.
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| Baby American Crocodile #4 |
American crocodiles, unlike American alligators, are extremely susceptible to cold and live exclusively within tropical waters. During 2009, unusually cold weather in southern Florida killed about 150 wild American crocodiles.
Crocodiles ferociously guard their nests. But, unlike Alligators, adult Crocodiles leave the nesting areas within a day or two, leaving the hatchlings on their own. The hatchlings rapidly disperse from their nest and fend for themselves. Most baby Crocodiles do not survive, being preyed upon by raptorial birds and larger fishes, Pythons and Raccoons.
Those that survive grow rapidly, feeding on insects, fish, frogs and, sometimes, each other. Crocs can live to 70 years old.
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| Flamingo boat tour, Buttonwood Canal: baby American Crocodile #5 |
Of course, far more common in the Everglades is the American Alligator, even though they were in relatively short supply when Caty and I visited. Who would have guessed we would see more Crocs than Gators?
The American Alligator, which can reach more than 18 feet long and weigh up to 1,000 lbs., inhabits freshwater wetlands, such as marshes and cypress swamps. It is distinguished from the Crocodile by its broader snout, overlapping jaws and darker color, and is less tolerant of saltwater but more tolerant of cooler climates. They vary from long and slender to short and robust and, when the jaws are closed, the edges of the upper jaws cover the lower teeth which fit into the jaws' hollows. Adult Alligators may be olive, brown, gray or black, while their undersides are cream-colored.
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| Shark Valley tram: American Alligator |
Alligators play an important role as ecosystem engineers" in wetlands because they create Alligator holes, which provide both wet and dry habitats for other organisms. Throughout the year, but particularly during the breeding season, Alligators bellow to declare territory and locate mates. Alligator nests are made of vegetation, sticks, leaves and mud, which heats as it decays, helping to keep the eggs warm. The temperature determines their sex; warmer eggs produce males and cooler eggs produce females. We didn't see any babies, although I did see some back in 2014.
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| Shark Valley tram: baby American alligators, photographed May, 2014 |
Historically, hunting had decimated the American Alligator, resulting in their listing as an endangered species. Conservation efforts removed them from the list in 1987.
When on land, alligators move either by "sprawling" or " high walking." In the water, Alligators swim like fish; moving their pelvises and tails from side to side. They have the strongest laboratory-measured bite of any living animal, but the muscles opening their jaw are weak enough to be held closed by hand or tape when an Alligator is captured.
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| Shark Valley: American Alligator |
An Alligator's abdominal muscles can alter the position of its lungs within its torso, thus shifting the center of buoyancy, which allows the Alligator to dive, rise and roll within the water.
An Alligator's diet is determined largely by its e size and age and the size and availability of prey. Most will eat a wide variety of animals, including invertebrates, fish, birds, turtles, snakes, amphibians and mammals. Some have also been observed eating fruit. Hatchlings mostly feed on insects, insect larvae, snails, spiders and worms. As they grow, Alligators gradually expand to larger prey. Once an Alligator reaches adulthood, any animal living in the water or coming to the water to drink is potential prey. However, most animals captured by Alligators are considerably smaller than the Gator itself.
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| Shark Valley tram: American Alligator |
Adult Alligators hunt both on land (up to 70 ft. from water) and in the water. They typically ambush prey and pull them underwater to drown. Alligator's teeth, which can bite though a turtle's shell or a moderately sized mammal bone, can grip prey, but cannot rip or chew flesh.
Alligators have been documented using lures to hunt prey such as birds, putting them among the few reptiles recorded to use tools. By balancing sticks and branches on their heads, they attract birds looking for suitable nesting material and then kill and consume them.
An Alligator can live up to 50 years.
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Shark Valley: American Alligator |
While events of predation by Burmese Pythons on Alligators and vice versa have been observed, no evidence of a net negative effect has been seen on alligator populations.
Alligators are capable of killing humans, but are generally wary enough not to see them as a source of potential prey. Mistaken identity leading to an attack is always possible, especially in or near cloudy waters. There has been only one documented attack on a human in the Everglades, which occurred about 15 years ago when a young boy fell off his bicycle onto a Gator. His parents rescued him and all survived.
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| Shark Valley: American Alligator |
Of course, there are many other creatures in the Everglades, including a variety of medium-sized Orb-weaver Spiders ...
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| Anhinga Trail: Orb-weaver Spider |
... to very large Golden Silk Orb-weaver Spiders ...
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| Shark Valley: Golden Silk Orb-weaver Spider |
One must be very careful when walking about because their giant webs are everywhere.
We also saw a Florida Red-bellied Turtle ...
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| Anhinga Trail: Red-bellied Turtle |
... and a Florida Softshell Turtle (which we initially thought was dead because of its odd posture) ...
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| Anhinga Trail: Softshell Turtle |
And, of course, there are lots of beautiful insects, including the Halloween Pennant Dragonfly, so named because of its bright orange and yellow coloration ...
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| Anhinga Trail: Halloween Pennant Dragonfly |
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| Shark Valley tram: Zebra Longwing Butterfly |
We had only the equivalent of two days in the Everglades, but we did manage to do most everything you can. If you go, make sure you travel to Flamingo and take the boat trip.
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| Flamingo Visitor Center |
Also, take the Shark Valley tram tour. This way you get to see two different aspects of the Everglades.
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| Shark Valley tram: observation tower |
We were also able to drive to Chokoloskee on the eastern, Gulf side, but didn't have time to take a boat tour as I had done in 2014. That's a good idea, as well.
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| Chokoloskee boat tour: Osprey, photographed in 2014 |
Trip date: December 27, 2015-January 3, 2016
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