A record number of American Crocodile hatchlings have been counted in Everglades National Park this summer, a positive development for this iconic Everglades species, University of Florida scientists say.
Frank Mazzotti, a University of Florida Institute of Food and Agricultural Sciences professor has monitored the south Florida crocodile population since 1978. This summer, he and his team of researchers that included Michiko Squires, Seth Farris, Rafael Crespo and research coordinator Jeff Beauchamp, caught, marked and released 962 hatchlings within the confines of the national park.
“Overall, with the exception of a short term setback following an extreme cold weather event in January 2010, we’ve been seeing marked improvements in the nesting effort of crocodiles in the park since 2003, especially in the Cape Sable area. Increased nesting and this summer’s record hatchling numbers are good signs for this threatened species and indications that system restoration efforts are indeed working,” declared Mark Parry, Park Biologist.
Due to extensive habitat degradation and over hunting American crocodiles were federally listed as endangered by the United States Fish and Wildlife Service (USFWS) in 1975. Recovery of the crocodile has been a story of cautious success in south Florida, as there are more crocodiles in more places today than there have been for at least the previous thirty-five years! While the USFWS reclassified this species in Florida from endangered to threatened in 2007, the crocodile still faces problems of habitat loss and environmental changes to their habitat.
The coastline of Everglades National Park, prime habitat for the American crocodile, was largely untouched by humans until a network of canals was dug in the 1920s to accommodate agriculture and residential development. This change in the hydrology triggered environmental changes that negatively impacted crocodiles as they are extremely sensitive to changes in salinity and water levels.
As the ecological impacts of these drainage systems were better understood, a series of efforts to plug the canals were attempted with most failing after a period of time. The more recent efforts appear to have been more successful and indications are that the salinity and water level conditions needed for young crocodiles to thrive are improving. The newest canal plugs, completed in 2010, are expected to substantially restore habitat quality for many species of flora and fauna. This restoration is particularly promising for the continued recovery of crocodiles throughout the park.
In light of these recent improvements, plans for additional plugs as part of the larger ecosystem restoration effort are underway (made possible by a generous donation by the Everglades Foundation and support of the South Florida National Parks Trust).These additional restoration plans to plug coastal canals in the national park aim to prevent salt water intrusion and fresh water losses to tide.
“What we hope is the lesson is that ecosystem restoration efforts can work. If the signal is correct here, we can monitor that improvement by looking at ecological responses – and crocodiles make good indicators,” Mazzotti said.
The outlook for crocodiles in Florida is optimistic and an excellent example of endangered species conservation success. Although the worldwide population of American crocodile is federally listed as endangered, the status of the Florida population has been changed to threatened because of a recent sustained increase in numbers, particularly nesting females. The nesting population continues to slowly increase, both in abundance and nesting range since effective protection of animals and nesting habitat was established. Protection of the remaining crocodile habitat in Florida and the restoration of the Everglades ecosystems will help ensure the survival of this species in the wild.
Linda Friar is the Cheif of Public Affairs for Everglades and Dry Tortugas National Park.
Photos courtesy National Park Service unless otherwise notated.