The Crocodile's Power Play - Until Everglades habitat is restored, some unexpected nesting sites are helping the American crocodile come back in South Florida

National Wildlife, Feb-March, 2002 by Don Stap

ON A STARRY EARLY SPRING NIGHT in South Florida, biologist Joe Wasilewski steers an airboat down a canal near Biscayne Bay. Suddenly, he kills the engine and jumps from the pilot's seat. Leaping onto the bow of the boat, he dives headfirst across the hull. His upper torso disappears over the prow, where moments earlier a spotlight picked out two shining, red eyes just above the surface of the water. Wasilewski thrashes in the water for a few seconds, then pulls his catch onto the boat: a three-and-a- half-foot specimen of North America's rarest reptile, Crocodylus acutus, the American crocodile. "Now you've seen the real 'Crocodile Hunter,'" Wasilewski says with self-mocking delight.

A crocodile expert, Wasilewski once was one of the few Floridians aware that these shy, reclusive reptiles live in the warm waters of South Florida. But that has started to change. Increasingly crocodiles have been showing up in populated areas-- from inland waterways to golf course ponds. Their numbers have doubled since 1975, when they were federally listed as an endangered species and only 200 to 400 remained in the United States. Whether this trend continues depends upon the restoration of the Everglades, which historically provided key habitat for the species. But the reason for the crocodile's recent population boost is unexpectedly linked to a power plant adjacent to Biscayne Bay. The crocodile Wasilewski just captured came out of one of the plant's cooling canals.

These canals--all 168 miles of them--allow the water coming from the generators at Florida Power and Light to cool before reentering the bay. When the company constructed them in the 1970s at its Turkey Point plant, it unknowingly created habitat for crocodiles, which dig their nests in the loose substrate between the canals. When hatchlings were discovered there in 1978, the company began monitoring the crocs on its property.

As the principal researcher at Turkey Point since 1989, Wasilew- ski, much to his delight, has watched the number of nesting crocodiles steadily increase. Last year, he found 17 successful nests. "They're smart animals," he says. "It didn't take them long to figure out that this was a good place to nest." About 60 adult and subadult crocodiles--one-tenth of those surviving in the United States--live in these cooling canals.

In addition to Turkey Point, crocodiles nest in two other areas in South Florida: the southern mainland portion of Everglades National Park and northern Key Largo, where they are protected by the 6,600-acre Crocodile Lake National Wildlife Refuge, established in 1980.

Historically, the American crocodile's range in Florida extended as far north as Lake Worth on the east coast of the state and Fort Myers on the west coast. Most estimates put the original population at only 1,000 to 2,000 animals. But in the last 100 years, poachers turned crocodiles into luggage, and mangroves and marshes became mall parking lots and two-stall garages. The crocodile population dwindled until only an estimated 20 nesting females remained in the early 1970s.

No one knows this history better than Frank Mazzotti, a University of Florida wildlife biologist who has devoted his life to the elusive reptile that was first identified in the United States little more than a century ago. In 1977 Mazzotti, then a graduate student, began assisting with fieldwork on the crocodile in Everglades National Park. At the time, little was known about the animal except that it appeared to be in dire straits. Mazzotti's work led to a Ph.D. dissertation on the American crocodile and a dedication to the croc's welfare that seems to know no bounds: He once gave mouth-to-mouth resuscitation to a baby crocodile that he rescued from the clutches of a blue crab. The crab had nearly drowned the hatchling, but the scientist blew into the crocodile's mouth until it spit out water and began breathing again.

Mazzotti's research has brought about a better understanding of the crocodile's life history and an appreciation for the animal's demeanor. He has discovered that the temperament of this species is nothing like its relatives in Africa and Australia, which are feared as man-eaters. Of the world's 21 species of crocodiles, "this crocodile is a real sweetheart," says Mazzotti, who adds that there are no known cases of a crocodile killing a human in the United States.

The American crocodile is even less aggressive than the Florida alligator, with which it is frequently confused. A crocodile can be distinguished from an alligator by several traits, most conspicuously by its narrower snout and its coloration--an olive green to gray-brown mottled with black. The alligator is uniformly black. In addition, the fourth tooth on the bottom on each side of the croc's mouth protrudes outside of the upper jaw.

Florida is the northernmost extension of the American crocodile's range, which includes Cuba, Jamaica, Hispaniola and the Caribbean coast from Venezuela to the Yucatan as well as the Pacific coast from Peru to Mexico. But the Florida subspecies has been completely isolated from its relatives for at least 60,000 years.