Florida’s swamps and marshes contain some of the densest concentration of plants and animals in the United States, and it is the only place in the world where alligators and crocodiles live in the same habitat. As recently as 1874, the crocodile habitat reached as far north as Lake Worth, and at one may have been killed there in the early 20th century. The American crocodile is a threatened species, and the American alligator was on the endangered list at one time. The alligator is called a “keystone” species, because a lot of other animals depend on it—on its vacated burrows—for survival.

Florida’s swamps and marshes are home to several species of endangered and protected birds, including the bald eagle and snail kite. Thankfully, with habitat protection and regulation the bald eagle is making a comeback. Ospreys and eagles recovered from a drastic decline in population in the 1950s to 1970s due to insecticides that are now banned.

With all the water around, it’s no surprise that wetlands are home to many types of wading birds, such as roseate spoonbills, herons, and egrets. In 1874 there was a major bird rookery on Munyon Island in Lake Worth, but plume hunters wiped out the population. The Florida sandhill crane, a threatened species, is joined every winter by greater sandhill cranes from the north.

Florida was also the winter home of the majestic whooping crane, the tallest bird in North America, but hunting and habitat loss wiped them out by the 1920s. Recently people have tried to teach “whoopers” to migrate to Florida again by following an ultra-light airplane. Wood storks have long been on the state and federal endangered species lists, but their numbers are increasing in Florida. Their presence in the wetlands means there are also a lot of fish and other organisms in the water, and the ecosystem is healthy.

Mammals of the marshland include the raccoon, marsh rabbit, squirrel, river otter, and the non-native armadillo. The Florida black bear, the state’s largest land mammal, is classified as a threatened species by the State of Florida. As the “forests of the wetlands,” cypress swamps provide habitat to many other wildlife species. The abundance of hollow trees provides homes for many birds and tree-dependent mammals.

The density of plants here, such as many different fern species, also creates a diverse ecosystem. Plants that grow on other plants without being dangerous to their hosts, called “epiphytes,” include orchids, bromeliads, and air plants, such as Spanish moss. More epiphytes are found in south Florida than in any other place in the United States. Swamps and marshes also filter pollution, absorbing small amounts of runoff and preventing it from entering rivers and streams.