Restoration of The Everglades - Wildlife Concerns

Wildlife Concerns

The intrusion of urban areas into wilderness has had a substantial impact on wildlife, and several species of animals are considered endangered in the Everglades region. One animal that has benefited from endangered species protection is the American Alligator (Alligator mississippiensis), whose holes give refuge to other animals, often allowing many species to survive during times of drought. Once abundant in the Everglades, the alligator was listed as an endangered species in 1967, but a combined effort by federal and state organizations and the banning of alligator hunting allowed it to rebound; it was pronounced fully recovered in 1987 and is no longer an endangered species. However, alligators' territories and average body masses have been found to be generally smaller than in the past, and because populations have been reduced, their role during droughts has become limited.

The American Crocodile (Crocodylus acutus) is also native to the region and has been designated as endangered since 1975. Unlike their relatives the alligators, crocodiles tend to thrive in brackish or salt-water habitats such as estuarine or marine coasts. Their most significant threat is disturbance by people. Too much contact with humans causes females to abandon their nests, and males in particular are often victims of vehicle collisions while roaming over large territories and attempting to cross U.S. 1 and Card Sound Road in the Florida Keys. There are an estimated 500 to 1,000 crocodiles in southern Florida.

The most critically endangered of any animal in the Everglades region is the Florida panther (Puma concolor coryi), a species that once lived throughout the southeastern United States: there were only 25–30 in the wild in 1995. The panther is most threatened by urban encroachment, because males require approximately 200 square miles (520 km2) for breeding territory. A male and two to five females may live within that range. When habitat is lost, panthers will fight over territory. After vehicle collisions, the second most frequent cause of death for panthers is intra-species aggression. In the 1990s urban expansion crowded panthers from southwestern Florida as Naples and Ft. Myers began to expand into the western Everglades and Big Cypress Swamp. Agencies such as the Army Corps of Engineers and the U.S. Fish and Wildlife Service were responsible for maintaining the Clean Water Act and the Endangered Species Act, yet still approved 99% of all permits to build in wetlands and panther territory. A limited genetic pool is also a danger. Biologists introduced eight female Texas cougars (Puma concolor) in 1995 to diversify genes, and there are between 80 and 100 panthers in the wild as of 2008.

Perhaps the most dramatic loss of any group of animals has been to wading birds. Their numbers were estimated by eyewitness accounts to be approximately 2.5 million in the late 19th century. However, snowy egrets (Egretta thula), roseate spoonbills (Platalea ajaja), and reddish egrets (Egretta rufescens) were hunted to the brink of extinction for the colorful feathers used in women's hats. After about 1920 when the fashion passed, their numbers returned in the 1930s, but over the next 50 years actions by the C&SF further disturbed populations. When the canals were constructed, natural water flow was restricted from the mangrove forests near the coast of Florida Bay. From one wet season to the next, fish were unable to reach traditional locations to repopulate when water was withheld by the C&SF. Birds were forced to fly farther from their nests to forage for food. By the 1970s, bird numbers had decreased 90%. Many of the birds moved to smaller colonies in the WCAs to be closer to a food source, making them more difficult to count. Yet they remain significantly fewer in number than before the canals were constructed.