An Everglades bestiary: Native and exotic populations of the ’Glades

Early map makers had to deal with large stretches of territory that had never been explored. The empty areas on their maps, labeled “terra incognita,” or unknown lands, often bore an additional inscription: “Here be dragons.”

This would be an appropriate and really quite accurate label to add to current maps of the Everglades, except that now we know those dragons as alligators. The American alligator, or alligator missipiensis (a name which seems a real slight to Florida), could also be considered a dinosaur, as they have survived essentially unchanged since the Cretaceous era, and been a part of the North American landscape for over 8,000,000 years.

The alligator is the animal most associated with the Florida Everglades, a primitive but perfectly evolved and efficient killing machine that ruled the swamps for millennia, before being nearly wiped out by an even more ferocious predator, homosapiens, aka man. Alligators were placed on the endangered list in 1967 under a precursor to the the Endangered Species Act, but with a little respite from unbridled hunting their numbers once again swelled, to the point where they are common, sometimes too common.

Over one million are estimated to live in Florida, and any body of fresh water in the state must be considered as a likely refuge for an alligator.

Alligators are the original native Floridians, although another species might dispute their claim – the mosquito, jokingly referred to as Florida’s state bird. The mosquito’s numbers dwarf that of alligators, and certainly the human population, with admittedly rough estimates guessing at 10 million to as many as 100 million mosquitoes for every person. That would be where there are people; in much of the Everglades, there are essentially none, so it can seem as though all 10 million are swarming up to get a closer look, and perhaps a taste of blood, from you when you show up. Mosquitoes have had more press than alligators recently, as carriers of the dreaded Zika virus, particularly the Aedes aegypti species.

After concluding a recent three-part series on the Everglades in this space, it seemed we had given short shrift to the local fauna, so this is an attempt to tell a little of their story. The Everglades teem with wildlife, which can be sorted in various ways.

They can be separated into land animals, fish, and birds, along with those insects. They could be grouped by warm-blooded mammals such as the panther, otter, black bear, versus the cold-blooded reptiles and amphibians. You could divide them into the mythical – the swamp ape – versus everything else. But one important distinction is between the native species and the exotics.

Alligators belong in the Everglades, more than we do. Ditto the bobcat, the raccoon, the gar, the ibis and the heron. But exotic or invasive species, most of them introduced through human action, have found a hospitable ground, often with no natural predators, and spread rapidly throughout the ecosystem.

There are scores of exotic plant species, such as hydrilla, Brazilian pepper, acacia and melaleuca trees. There are exotic amphibians such as the cane toad and Cuban tree frog, which crowd out the native species. But perhaps the most impactful, and fearsome, is the Burmese python. These snakes, an apex predator in their native Southeast Asia, at the top of the food chain, are ideally suited to life in the Everglades, where they have been introduced by pet owners who could no longer manage “Cuddles” once he reached eight feet long, or through accidental escapes.

Virtually undetectable in the wild, impossible to track through heat-sensing technology due to being cold-blooded, the pythons have decimated the small animal populations in the Everglades, and even been caught on video subduing and eating alligators. Recent python “roundups” have netted small numbers of the snakes, but estimates of their numbers in South Florida by wildlife biologists range from at least 30,000 to over 300,000. One 14-foot specimen was captured by Rookery Bay interpretative naturalist Fred Allen, and a 140-lb., 16-foot Burmese python, the record, was taken this January during the roundup in Collier County. There is no record of any attacks on humans by pythons in the wild, but a quick YouTube look at how they take their prey should make anyone eager not to be the first.

The native Florida panther, meanwhile, is hanging on by its claws, with population reduced to approximately 180, according to the Florida Panther Net, and only reaching those numbers due to importation of breeding stock from Texas. With their habitat pressured by human development, they fall victim to humans when crossing roads, which is why you are not allowed to exceed 60 mph at night heading to Miami on the Tamiami Trail.

There are brighter areas in the endangered species picture. Ospreys, along with other birdlife, have made a marked comeback since pesticides such as DDT were banned in the wake of publication of “Silent Spring,” Rachel Carson’s classic work on the danger of chemicals in nature.

But one of the most important species in the Everglades – along with the mosquito, which is a vital link in the food chain, meaning that when you get bitten by one, you are also a vital link in the food chain – is the oyster. This simple mollusk, besides providing food for centuries of Calusa Indians, who piled up their shells into mounds which are still the highest land in South Florida, and helping sales of hot sauce and horseradish to raw bars, are the natural building block of our coast.

According to Michael Savarese, Ph.D., of Florida Gulf Coast University, a marine scientist who has done substantial primary research on what rising sea level could mean for this area, climate change locally could come down to a race between water level and oysters. The growth or accretion of oyster beds, which provide areas for mangrove propagules to take hold, becomes impossible when the water level rises faster than the mollusks can rise up from the sea floor, resulting in “drowned mangroves,” and barrier islands start to disappear or migrate inland. The result, he said in a talk on Marco Island, could be the Gulf of Mexico literally lapping at the roadbed of the Tamiami Trail in coming decades. Cape Romano, the barrier island system just south of Marco, has been steadily fragmenting into smaller islands in recent years.

And back to alligators, they are not the only long, scaly reptile inhabiting the Everglades. In more brackish watery areas, the American crocodile coexists in the ’Glades with the alligator, the only place in the world that is true. A nest of crocodiles can be seen right past the end of the runway at the Marco Executive Airport, something to think about next time you fly out.