Preserving Florida's Endangered Species

Natural History, Dec, 1999

A journey through Florida's wild species and spaces

Canaveral National Seashore is the longest stretch (24 miles) of undeveloped beach on Florida's east coast. Fourteen endangered species make their home within its boundaries.

REACHING FOR THE Caribbean like a thumb splayed from the North American mainland, the long Florida peninsula links the temperate north and tropical south in a rich tapestry of forests, swamps, prairies, pellucid springs, meandering rivers, lakes, marshes, barrier islands, and sandy beaches that support thousands of plant and animal species. Called a "paradise" by its fervent admirers, it is a land that has been shaped by heat, rain, fire, periodic freezes, wind (often from tornadoes and hurricanes), ocean tides and currents, and, more recently, people.

During the past century, hunting, fishing, logging, agriculture, mining, and urbanization have taken a heavy toll on natural Florida, even as the state and federal governments, as well as private groups, have established parks and preserves, regulated hunting and fishing, and protected critical habitat. Today, Florida's population stands at 13 million and counting, fourth highest in the nation; its 100 species of plants and animals listed under the Endangered Species Act rank it third highest.

In recent years, Florida has launched a number of innovative programs to aid endangered species and protect and restore imperiled habitat. Aided by basic research into the biology of plants and animals, genetics and population dynamics, and computer modeling of natural systems, the state is at the forefront of international environmental efforts.

The most ambitious of these focuses on the Everglades region of South Florida, fragmented during the past century with 1,400 miles of canals and spillways that have disrupted the natural balance of wet and dry and made the unique "river of grass" one of the most fragile ecosystems in the world.

Now awaiting Congressional action, a $7.8-billion recovery plan -- the largest and most complex in history -- would extensively alter the drainage system so that water flow in the Everglades would more closely mimic pre-development patterns. The project is expected to revitalize the region's vegetative and aquatic communities, including Florida Bay and the Florida reef tract, and to benefit many of its 68 threatened and endangered species, including the Florida panther, snail kite, wood stork, Cape Sable seaside sparrow, crocodile, and green turtle.

ONCE RESIDENT THROUGHOUT THE SOUTHEASTERN UNITED STATES, the Florida panther is now found only in South Florida, primarily in Big Cypress Swamp. The 50 to 70 remaining big cats -- threatened by inbreeding and geographic isolation that leave them vulnerable to disease, congenital defects, and natural disasters -- are ranked among the most imperiled mammals in the world. Recently, in a bold experiment, state wildlife officials introduced closely related Texas cougar females into the region, hoping to enhance the panther's genetic variability and thereby ward off, at least for now, what many biologists saw as its impending extinction. Still, more cats are needed in more places to insure the Florida panther's survival.

With its 45-inch wingspan, the rare snail kite cruises above freshwater marshes, hunting its sole prey, apple snails, which it extracts from their shells with its curved beak. The 500 remaining snail kites are found primarily in the Everglades, and ecologists expect that improved water flow will boost their numbers by increasing the supply and availability of apple snails.

Hunting by touch with their bills, wood storks require pools of freshwater that concentrate fish during South Florida's dry season (November to May) to feed themselves and their young, and thus are highly sensitive to changes in water levels. Roosting in greatest numbers in the Corkscrew Swamp Sanctuary northwest of Naples, the storks can be found well into Central Florida, including Kennedy Space Center.

Once common along South Florida's coasts, the crocodile was hunted until only a small population remained in mangrove-fringed saltwater estuaries of Florida Bay lying within the Everglades National Park and a sanctuary on Key Largo. Protected since 1979, this ancient reptile has recently expanded its range to include the cooling lagoons of Turkey Point Nuclear Power Plant near Homestead.

For eons Florida beaches and waters have hosted sea turtles, and, although their numbers are significantly reduced, four of the six protected species -- the leatherback, the world's largest turtle; the green, a herbivore favored by gourmets and sailors; the loggerhead; and the hawksbill -- still heave themselves ashore at night in a physically exhausting struggle against gravity and loose sand to lay their eggs and then return to the sea. Hutchinson Island, Hobe Sound, and Canaveral National Seashore are among the prime nesting beaches for green, leatherback, and loggerhead turtles. Hawksbill turtles now only visit beaches in the Keys and the southern part of the peninsula.