National Geographic Today
A conservation success story is crawling through the swamplands of South Florida, northernmost home of the American crocodile, Crocodylus acutus.
The crocodile, whose range extends to Peru, is listed as endangered by U.S. and international wildlife agencies. Thirty years ago, because of hunting and habitat loss, the crocodile population in South Florida had dwindled to less than 400.
Now, though, the number is up to 1,000enough to prompt the U.S. Fish and Wildlife Service to consider down-listing the crocodile's status to "threatened," according to Britta Muiznieks, a U.S. Fish and Wildlife recovery biologist who specializes in endangered South Florida wildlife.
To help preserve the species, Frank Mazzotti and his colleague Mike Cherkiss, wildlife ecologists at the University of Florida in Gainesville, are conducting the longest-running research project and census ever devoted to the American crocodile.
Since 1977 Mazzotti has prowled the South Florida swamps and coastal estuaries in search of the creatures.
"I study crocodiles because they're endangered and ecologically important, and because they're the last of the dinosaurs. They're really our only chance to understand how that group, which once ruled the Earth, was able to survive," Mazzotti says.
To gather biological data, Mazzotti and Cherkiss capture, measure, and tag the crocodiles, then release them. The statistics go into a "croc catalogue" that helps track the species' population growth and survival rates.
Looking for Eyeshine
Crocodile habitat stretches along Florida's coastal estuaries where salt water mixes with fresh and where mangrove swamps shield the reptiles from wind and waves.
"The (crocodile population) recovery has a lot to do with the restoration of the Everglades," Mazzotti says. The natural water flow helps establish the right mix of salt and fresh water for young crocodiles to flourish. Too much salt water imperils them.
During summer, when the crocodile eggs hatch, Mazzotti and Cherkiss board their 15-foot (4.5 meter) skiff and prowl the mosquito-infested swamps of Buttonwood Canal near the village of Flamingo. They've staked out the nesting sites and return to them to catch the hatchlingsmainly after dark. The researchers scan the water with handheld searchlights and head lamps, looking for what they call "eyeshine."
"At night their eyes shine like little bicycle reflectors and it makes them much easier to see," Mazzotti says.
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