Marco Island, Florida Photos & Stories

Crocodiles
by Maureen Sullivan-Hartung

Crocodiles, from the Greek word crocodilos, which means lizard, are large reptiles, that bear a striking resemblance to the alligator, and are believed to have descended from the dinosaurs. Crocodiles are known to have inhabited the earth for more than 200 million years, living in swampy areas and near riverbanks. Florida's native crocodile is an inhabitant of our saltwater shorelines, located along the mangrove-bordered southern shores of the Everglades National Park. Crocodiles are cold-blooded reptiles, with scaly skins, that seek a warm habitat year-round; and both sexes have been known to live up to 70+ years.

The crocodile's ears, eyes and nostrils are located near the top of the head and are exposed when the crocodile is floating on the surface of the water. The crocodile's eyes have a thin layer of membrane, called tapetum, behind the retina, that reflects light, which gives them their red dot glow at night. And, did you know that whenever you see a crocodile with its mouth open, it is actually cooling itself off...panting, much like a dog does?

There are 23 known species of crocodiles living on earth: those here in the U.S., Central and South America, Asia, China, Cuba, Africa, Australia, India and even New Guinea. Female crocodiles generally reach an average length of 12-feet; however, some have reached lengths of 15 feet or more; with males reaching up to 23-feet in length. In other countries crocodiles have reached lengths of 30 feet; and then the smallest is known as the dwarf crocodile which is no larger than four or five feet. Crocodiles versus Alligators

The crocodile is readily distinguishable from the alligator by its long, narrow snout versus the thicker, shorter snout of the alligator. The saltwater crocodiles are known to attack and eat humans, while their alligator counterparts often make a hasty retreat when approached. Alligators live only in the U.S. and China, while crocodiles can be found in the U.S., Africa, Asia, Cuba, South America and elsewhere. American Crocodiles display a tooth on either side of their lower jaw - even when their mouths are closed - and you can only see an alligator's teeth if their mouths are open. Although alligators and crocodiles belong to the same family, they belong to totally different sub-families.

Both species are protected under the state and federal laws. The crocodile is listed as "an endangered species", while the alligators are termed as "threatened" under the same act - the Endangered Species Act.

Diet

Rabbits, turtles, raccoons, water birds, crabs and fish make up the natural diet of the adult crocodiles. Did you know that crocodiles can live for months at a time without feeding, due to the fat they carry. Most crocodiles have been found with stones in their stomachs. Even though the crocodiles have razor-sharp teeth, they shred their food, and these stones help with the grinding process - as well as helping to keep them afloat in the water - much like a ballast on a ship's hull. Crocodiles are able to replace lost or worn-out teeth by growing new ones. Lunging out of the water, the crocodile's prey is usually crushed and swallowed, or even thrashing and rolling, while dragging it deeper into the water and drowning it, which will also aid in dismembering the prey into smaller pieces for eating, since the crocodile's stomach is usually smaller than its prey. Speaking of prey, the most terrifying crocodile is the Nile Crocodile, which can actually take down a water buffalo - which is approximately the size of a cow!

Were you aware that the pressure of a crocodile's bite is more than 5,000 pounds per square inch? Compare that to 2,000 pounds per square inch for a large alligator - and compare that to a rottweiler at 335 pounds per square inch and 400 pounds per square inch for a great white shark. The crocodile is by far the strongest bite of any animal. Reproduction

Reaching sexual maturity at roughly 7-feet long, when the female crocodile is between the ages of 10-13 years; courtship and mating ensue, and the female then lays her clutch of eggs, roughly 20-60, in a nest made from mounds of shell and sand, and located near the brackish shoreline. The babies, or hatchlings, measure approximately 10-inches and begin life as yellowish-tan to gray in color with dark cross markings on the body and tail - which fade as the crocodile grows. Incubation will take approximately 80 days, and the female will return to the nest to assist the hatchlings in breaking free from the egg, by gently cracking the eggshells in her mouth.

The crocodile embryos do not have sex chromosomes. Like turtles, the sex is determined by the temperature of the nest - with males produced at roughly 31.6 degrees C (89-degrees F), and females at either slightly lower or higher temps. Females produce only one clutch per year; and sadly, more than half of these babies will not survive their first year, becoming prey to other animals themselves.

Threats

Even though their numbers are still well below historic numbers, the American Crocodile population in South Florida has increased substantially since the 1970s. Once hunted for their hides, today's biggest threats no doubt would be both the poaching as well as the encroachment to the habitat of the animal, which has been on the rise since the human race in South Florida began. Sadly too, crocodiles are killed on our busy highways, on an average of three to four per year. Hurricanes and other catastrophic events here in Florida have also been known to limit the number and distribution of the species in our state. Both animals are also hunted for their skin in creating shoes, bags and luggage. And, don't forget, crocodile meat is also consumed by humans as well. The meat is white and has a taste between a chicken and crab.

Additional Reading:

Crocodiles & Alligators by Seymour Simon, 2001

Crocodiles & Alligators by Stephen Garnett & Charles A. Ross, 1989

Crocodile: Evolution's Greatest Survivor by Lynne Kelly, 2007

Florida's Fabulous Reptiles & Amphibians by Pete Carmichael & Winston Williams, 1999

Crocodiles & Alligators of the World, by David Alderton & Bruce Tanner, 2004

Swimming with Crocodiles: A True Story of Adventure & Survival by Will Chaffey, 2011

Alligators & Crocodiles by Gail Gibbons, 2011

Alligators & Crocodiles! Strange & Wonderful by Laurence Pringle & Meryl Henderson, 2009

The ABCs of the Florida Landscape is written by freelance writer Maureen Sullivan-Hartung who has resided in Naples for nearly 30 years and loves learning about all aspects of the local flora and fauna. Another passion of hers is history and she authored a book in November 2010, titled, Hidden History of Everglades City & Points Nearby, published by The History Press. Check her website for the book's availability or additional information about the author at: www.maureenwrites.com
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