Birds
During the 19th century, according to the Comprehensive Everglades Restoration Plan, there were so many wading and migratory birds in Florida's Everglades that their numbers made the skies darken. Numbers today are vastly reduced through loss of habitat and over-hunting. These birds are vital to preserving the integrity of the ecosystem as a whole. For example, the endangered Snail Kite survives exclusively on the apple snail and is therefore important for keeping numbers of the snail in check.
Reptiles
The endangered gopher tortoise is one of the world's oldest living species, according to the Gopher Tortoise website. The animals graze on vegetation and their droppings are important in helping to distribute seeds. The endangered eastern indigo snake lives a communal existence with the gopher tortoise and the presence of each is vital to the survival of the other. The Seaworld website says that the indigo snake is an integral part of the scrub ecosystem as it helps to control the populations of many species found there.
Land Mammals
The endangered Florida black bear is the largest native land mammal in the State. The shy and secretive black bear is an omnivore and eats everything from acorns to armadillos. Because the bear naturally wanders across a large geographic area, it helps distribute the seeds that it has consumed through its droppings. Florida's state animal, the Florida Panther, is highly endangered. The Defenders of Wildlife website says that the diet of these panthers helps keep numbers of deer, rabbits, raccoons and birds in check.
Marine Mammals
West Indian manatees, also called sea cows, are large aquatic mammals that are about 10 feet long. The endangered animals are herbivores and will repeatedly return to the same beds of sea grass to graze, thus preventing grasses from dominating an environment. The endangered fin or fin-back whale is second only to the blue whale in size and weight. The whales help keep populations of krill and schooling fish in check.