Iguanas make prey of helpful species
Lizards are ubiquitous in South Florida. They live in all kinds of places from public parks and wilderness to office buildings and back yards.
Many lizards, experts say, simply do not belong. They are among many invasive species in the region.
William H. Kern, an associate professor in the University of Florida’s Entomology and Nematology Department said that because Florida is a center of the exotic pet business there are lots of strange animals around. Usually, he said, the creatures “have escaped or been released” into the wild or elsewhere.
Many of the animals, especially lizards, come from other countries and in South Florida start to take over the supply of food.
Nature generally keeps the balance of animals and plants in check, Kern said. ”But,” he said, “South Florida doesn’t have an answer for invaders. Their populations just keep growing.”
Dr. Henry Lee, a research ecologist for the federal Environmental Protection Agency said the lizards are often a danger to people. He said they carry exotic diseases and pollute drinking water.
Some examples of imported lizards are the brown basilisk or Basiliscus vittatus, the knight anole or Anolis equestris and the green iguana Iguana iguana. All of them, experts say, cause mischief in South Florida. They kill smaller animals that are vital to the environment, the experts say, and also cause problems for people.
The brown basilisk is native to Central and South America, specifically, Belize, Colombia, Costa Rica and Panama.
Kern noted that the basilisk’s nickname, “Jesus Lizard,” is derived from its ability to run across the surface of bodies of water with its web-like feet.
Dick Bartlett is a reptile expert with decades of experience traveling the Americas and studying husbandry and captive care. He has written or co-written more than 30 books on reptiles and amphibians. He has worked with brown basilisks. They eat insects, small anoles and soft fruit, he said.
Sometimes, he said, when he walks up on a brown basilisk it becomes what he calls, “spastic.”
“They’ll run,” Bartlett said, “and if they do, you better hope they have a clear path.”
Bartlett said that around people’s homes basilisks sometime damage plants, flowers and lawn ornaments. He said they sometimes scratch and dent floors and walls. Often, Bartlett says, the animals are in a panic when the damage occurs.
The knight anole came to the United States from Cuba, experts say.
Ellen Dolan, an environmental scientist at the South Florida Water Management District in West Palm Beach, says that the first knight anoles were discovered in the United States on the old north campus of the University of Miami in the early 1950s. They have since been found in 13 other parts of Florida, she said. .
In a comparison to brown basilisks, Bartlett said, knight anoles are “on the opposite side of the spectrum when it comes to behavior.”
The knight anole is fiercely territorial. It is aggressive, Bartlett said. When it is threatened, he said, it changes colors and often extends its dewlap, a reddish-white flap beneath its chin.
The University of Florida’s Kern said he is concerned about the knight anole’s diet. “Fully-grown ‘knights’ devour smaller lizards, like geckos and the native anoles,” Kern said. “Those little lizards are responsible for keeping the insect population in check, like crickets and mosquitoes.”
Dr. Kenneth L. Krysko, who earned his doctorate in wildlife ecology and conservation and who has taught biology at Florida International University, has devised a method for capturing the knight anole.
Krysko attaches a dead dragonfly to a monofilament fishing line and casts it with a fishing rod toward a knight anole, often one that is in a tree.
The trick, he said, is to toss the dragonfly very close to the lizard. “The anoles latch on,” he said, “mistaking the bait for live food, and I gently reel my ‘catch’ down to the ground.”
He said that sometimes he catches nearly every lizard he goes after.
The green iguana, the experts say, is by far the most notorious invasive reptile in South Florida. They say the basilisk and the knight anole are often miss-identified as green iguanas.
Kern said green iguanas eat everything from “insects, lizards and other small animals” to “nesting birds and eggs” to such fruit as berries, mangos, tomatoes and bananas.
He said iguanas eat plants, shrubs, trees, orchids and other flowers. The iguanas damage sidewalks, seawalls and foundations by burrowing under them, Kern said. They also leave fecal droppings that are a source of salmonella, a common cause of food poisoning, the experts say.
When pet iguanas get frightened they sometimes bite, Kern said. Some years ago a 14-year-old boy in Hollywood, Fla., lost the tip of his right index finger while feeding a green iguana. The boy and his family liked iguanas and had collected seven all together.
Experts consider brown basilisks, knight anoles and green iguanas as “nuisance” species, Lee said, because they create what he considers to be “unacceptable ecological or economic damage” and threaten “human health.” #