The Croc Doc

Dec. 26, 1994
Dec. 26, 1994

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Dec. 26, 1994

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The Croc Doc

Wildlife scientist Frank Mazzotti is the best friend Florida crocodiles have

Hearing the subterranean cries of her young, the crocodile digs open the womb of sand, picks up a hatchling in her teeth and ferries it to the nearby shore of Florida Bay. By dawn, as their mother returns to a shallow inland bay to resume her solitary life in the Everglades, a knot of tiny crocodiles has formed in the beach wrack.

This is an article from the Dec. 26, 1994 issue Original Layout

To cross open water, a hatchling crocodile, which wiggles like a nine-inch fishing lure, must pass through a gantlet of tarpon and snook. If it survives it may live for 40 or 50 years, grow to be more than 12 feet long, weigh nearly 1,000 pounds and never lay eyes on a human being...other than Frank Mazzotti.

Mazzotti, a University of Florida wildlife scientist, has been monitoring crocodiles in Everglades National Park for 17 years. He has measured, weighed, poked, taped, tied, tagged and clipped more crocodiles in Florida than anyone else. He has even given mouth-to-mouth resuscitation to a drowning hatchling that was pulled below the surface by a hungry blue crab; he scaled his lips around the crocodile's throat and blew gently into its lungs until it coughed up water. (Mazzotti, who has eclectic reading habits, credits his knowledge of reptilian CPR to a Mad Magazine cartoon entitled "How to Give Artificial Respiration to a Lizard.")

Crocodiles are dual citizens of freshwater and salt water, of land and sea. Because hatchlings thrive in estuaries in which salt levels are about 10 parts per 1,000 (ppt)—seawater is 36 ppt—their well-being depends on the timing, location and quantity of the freshwater flow from the Everglades into the northeast corner of Florida Bay. A rise in the Everglades' crocodile population will be evidence that the U.S. government's efforts to restore the Everglades (the most ambitious ecological restoration that has ever been attempted anywhere) are paying off. In fact, it is the Army Corps of Engineers, the architect of the project, that is funding Mazzotti's crocodile work through the summer of 1995.

As he wades through gray water along the edge of Deer Key, an islet in Florida Bay, Mazzotti points to an eight-foot female less than 20 feet away. Slowly the beast rises in the water, her head and tail above the surface in what Mazzotti says is a territorial gesture. She sculls parallel to the beach, her eyes fixed on us. Mazzotti notes that, ferocious appearance to the contrary, she is a timid animal. In 1994, for instance, 14 out of 20 crocodile nests in Everglades National Park were built on isolated beaches that face unpeopled waters. American crocodiles are a far different beast from the Old World species, which does not fear humans and in fact considers them edible. A mother crocodile has a good memory, and she will abandon a nest site for years if she is pestered or if her eggs repeatedly fail to hatch.

Mazzotti binds what's left of his gray hair in a ponytail. He is 46 and as tan as a coconut. He says his interest in biology was inspired by his boyhood alter ego, Tarzan, and like the King of the Apes, he pretty much lives in a bathing suit—unless he is on a windless, mosquito-infested shoreline, in which case he leaves only his hands unprotected by layers of clothing. Mazzotti gestures constantly when he talks, and his voice still evokes the New York City suburbs, which is not uncommon in Florida. The son of a Long Island plumber, Mazzotti has, after a fashion, followed in his father's footsteps. He received a doctorate in ecology from Penn State in 1983 and has long been an authority on South Florida's wetlands. The region's 1,400 miles of canals, levees and dikes are a spectacular plumbing nightmare that only God could restore to free-flowing order.

Americans know there are alligators in Florida, but not even many Floridians suspect that crocodiles dwell in the swamp forests of their state. These estuarine swamps are the northernmost outpost of the American crocodile, Crocodylus acutus, a relic of the Mesozoic Era that is considered by many biologists to be a living dinosaur. (Ancient crocodilians were members of the group of giant reptiles called archosaurs, which included the fearsome tyrannosaur.) Sometime during the Ice Age, when sea levels were about 300 feet lower than they are today, the crocodile crossed the Florida Straits from Cuba and established a toehold on North America. It wasn't until 1822, though, that the American naturalist Constantine Samuel Rafinesque guessed that the "sharp-nosed alligator" of Florida was actually a crocodile. Another 47 years passed before the first specimen was collected in the now defunct Miami River.

Crocodiles have never been common in Florida, but their numbers have increased in the past two decades. Mazzotti places the population at about 400, which is distributed among three main habitats: northeast Florida Bay; north Key Largo, where crocodiles nest on spoil banks adjacent to canals in Crocodile Lakes National Wildlife Refuge and get hit by cars on U.S. 1; and the cooling canals of the Florida Power & Light station at Turkey Point on southwest Biscayne Bay. They move freely among the three sites and have been found as far north as Fort Lauderdale on the east coast of the state and Sanibel Island on the west. The bayside berms of Miami Beach once hosted a thriving population of crocodiles, but now, except in the pages of Carl Hiaasen's mystery Tourist Season, in which a behemoth eats assorted vacationers, crocodiles have shifted south in Biscayne Bay.

Once hatched, the crocodiles head for nurseries in the remote mangrove-lined creeks and basins that drain the east Everglades. From mid-July to mid-August, Mazzotti checks crocodile nests, hoping to intercept hatchlings before they disperse among the mangroves. One afternoon he takes his 15-foot skiff into the Taylor River, a branch of Taylor Slough, the principal drainage of the east Everglades, which pours its freight into Little Madeira Bay. At full throttle Mazzotti races the boat toward a wall of trees. One minute he is headed for the cleft that identifies the river, and the next he is inside deep-green, mosquito-filled shade.

Half a mile upstream the river cuts a bank of marl, an ancient beach that supports a forest of West Indian hardwoods (mahogany, Jamaican dogwood, pigeon plum, sea grape) in an otherwise dense forest of mangroves. Crocodile chatter wafts from a trellis of mangrove roots that rises from the coffee-colored water.

As Mazzotti determines that their mother has already dug into the nest and that there has been at least a partial hatch, tiny crocodiles begin to appear on roots, on the bank and sprawled on the water's surface like bathtub toys. Mazzotti wants them. I reach out and catch one...two...three...four. I place the crocs in a nylon bag and turn to see Mazzotti already submerged to his chest, making his way through a maze of overarching mangrove roots, three crocs in each hand. Together we catch 13.

Because the average clutch of 39 eggs takes approximately 86 days to incubate and may hatch over several days, and because some females nest communally, I ask if there might be viable eggs left in the nest cavity.

We scramble up the bank and tap on the trunk of a buttonwood whose roots reach into the nest. An underground chorus rises from the marl. We tap again. The hatchlings chirp some more. Mazzotti gently digs into the hard-packed marl. "My mother used to joke about the hatchlings being my kids," he says. "Come nesting season, don't bother me. If there's a wedding or a funeral, forget it, 'cause I'm watching my kids being born. Sorry."

One egg is hatching, so we wait it out, swatting mosquitoes and deerflies and no-see-ums. Then we cover the nest so that the rest of the crocodiles will have a chance to hatch.

Back at camp on Key Largo we take a few crocodiles out of their temporary digs—a cooler—where they have been swarming with their siblings. They are about to be weighed and measured. Each will also have its scales clipped in such a way so as to leave both an easily readable three-digit identification number and a birthplace code on the croc's ample tail. For example, a clipped number 7 scale on the right side of the double row of scales indicates that the croc was born in the Everglades.

The hatchlings are rubbery. On top they are gray-brown, intricately banded, stippled and mottled with black, like pieces of hand-tooled wood. This coloring can blend into a variety of backgrounds, and the crocs retain it for life. The undertail is white flecked with black. The animal's mustard-colored eyes have vertical black slits for pupils—night eyes. The teardrop-shaped ear openings slant away from the eyes. There are four toes on the animal's front feet, five on the hind. Only the first three toes of each foot are clawed. Proportionally, a hatchling's snout is shorter and smaller than an adult's.

A hatchling may look nothing like a human infant, but it is almost as adorable. The little crocs open their mouths but do not bite. These are maws that will one day pulverize large fish, small turtles, and herons, ducks, raccoons, perhaps even deer—virtually anything a crocodile can overpower and drown. It is easier to see the tiny rows of salt glands on the floor of a baby croc's mouth than to see those notorious but still nearly undetectable teeth.

Several days later, after the Taylor River hatchlings have been processed and released in the vicinity of their nest site, Mazzotti finds another clutch of creek-nesting crocodiles. Tonight he will process them and return them to Davis Creek, a short, mangrove-choked tributary that connects Joe Bay to Florida Bay. Mazzotti thinks he can take his skiff down the creek if I sit in the bow and saw mangrove branches and roots, hauling us downstream like a seaman pulling up an anchor.

Leaving Key Largo an hour before sunset, we see curtains of rain separated by thick yellow bars of sunlight slanting toward the western horizon. To the north the sky is bruised and congested. Visibility is reduced to a mile, and to the east, ragged patches of pink-tinted clouds drift south. Within 15 minutes the sky becomes a kaleidoscope, a Grand Canyon of the atmosphere. The congested north fractures into layers of gold, orange and pink, and in the east what was pink is now violet. Everything glows: Mazzotti's tanned face, emerald leaves, the gray, barkless mangroves that reach from the shallow water.

At Joe Bay just after sunset we are drifting on a mirror of russet water and processing hatchlings. The mosquitoes are relentless. Inside Davis Creek, trees close around us, sealing off the sky. I have a flashlight and a saw, which allow me to function as a headlight, a tree surgeon and an auxiliary motor. The flashlight wedged between my legs, I saw and pull, saw and pull. We inch forward, soaked from rainwater that pours off the leaves. Mazzotti sees the widely spaced red eyes of a crocodile off the bow. A tarpon jumps into the boat, and Mazzotti quickly tosses it back into the water. Eventually we give in to the inevitable forces of nature that have clogged the creek, and we release the hatchlings, reached earlier on foot, well short of their nest. Twelve tiny crocodiles linger around some roots, while a 13th dives. When the engine revs, the brood scatters.

Until Mazzotti has room to turn the skiff around, he backs out of Davis Creek. Most people think of crocodiles as they do sharks, rock-hard muscle welded to bone, beasts hard-wired to eat and perform a few other mindless tasks. I ask, "Is working with American crocodiles dangerous?" Mazzotti sweeps a hand back toward the mangroves and says, "I'm more worried about crossing U.S. 1 on a Friday night than I am about wading in the middle of the Everglades at midnight. The hardest thing you put up with here are mosquitoes, and they never color my memories."

As we return to Key Largo, phosphorescent worms rise from the sediments of Florida Bay. Agitated by the boat, a wake of glowing diatoms fans out across the Bay, a mirror of the Milky Way that runs across a cloudless, starry sky from Maine to Cuba.

PHOTOBEN VAN HOOKMazzotti refuses to be disturbed during nesting season when his nine-inch "kids" are hatching.PHOTOTED LEVIN[See caption above.]THREE PHOTOSTED LEVINHatchlings are scale-clipped for identification (above), measured (left) and weighed by Mazzotti.PHOTOTED LEVINUnlike its fearsome Old World counterpart, the American crocodile is wary of humans.

Ted Levin, who writes often on the outdoors, is working on a book about the Everglades.