Invasive Species of the Florida Keys
4 Non-Native Animals Causing Concern in South Florida
Dec 23, 2008
The Florida Keys boasts a unique subtropical ecosystem, home to several species that can’t be found elsewhere, such as the Key deer, Key Largo wood rat, and Lower Keys marsh rabbit. This delicate environment has been invaded by several non-native species, all brought into the Keys by humans. Some scientists argue that these animals endanger native wildlife by eating the same food, taking over the same nesting areas, and preying upon native plants and animals. But as development spreads in the Keys, some invasive species fill a niche in the changing landscape. The gypsy chicken and the iguana, both invasives, have become mascots of the “American Caribbean.”
Green Iguana
Though there is evidence that some iguanas lived in the Florida Keys over a hundred years ago, the population boomed when the lizards became popular in the pet trade in the 1980s. Unwanted pets were released, or escaped, and reproduced. Though many tourists and locals are fascinated by the ancient-looking reptiles, others complain that iguanas destroy native vegetation and pose a health hazard to humans by pooping in their pools and on docks. Despite their fearsome appearance, iguanas are vegetarians and do not attack people or pets, though they can deliver a stinging whip with their tail when provoked.
Gambian Pouch Rat
In 2000, an “exotics” breeder allowed several Gambian pouch rats to escape; Fish and Wildlife has been struggling to eradicate the animals ever since. These rats grow to be the size of raccoons, have no natural predators in the Keys, and eat anything from plants and fruits to bugs and eggs. The concern is that they compete with the endangered Key Largo wood rat and Lower Keys marsh rabbit, among other species. They may also consume endangered plants. The Gambian pouch rat has been linked to monkeypox outbreaks elsewhere, though there has been no evidence of monkeypox in the Keys’ population. Currently, the U.S. has banned the import of Gambian pouch rats.
Burmese Python
Biologists in Everglades National Park confirmed a breeding population of Burmese pythons in the Florida Everglades in 2003, presumably the result of released pets. Not long after, pythons were discovered in Key Largo. These snakes, which can grow to over 20 feet long and more than 250 pounds, pose a danger many threatened and endangered species: endangered Key Largo wood rats have been found in the stomach contents of captured pythons. There is also concern that the pythons are competing with native predators like the American alligator. U.S. Fish and Wildlife is considering listing the snakes as injurious wildlife, which would prohibit them from being imported.
Key West Gypsy Chicken
Colorful Key West gypsy chickens are the descendants of birds brought over from Cuba for cockfighting, egg-laying, and meat. Unlike modern chickens bred for meat and egg production, gypsy chickens are good fliers and great insect hunters. Many locals enjoy sharing the island with these birds, and believe the chickens help give Key West its Caribbean character. Others complain about being woken up by roosters crowing at all hours and get angry when the chickens scratch up their yards. People grumble about chicken poop, fret about the threat of “bird flu,” and lobby the city to control or eliminate the chickens. There is concern that the chickens displace native ibis, egrets, and other insect-and-lizard eaters. Others argue that the native birds are dwindling because of over-development, and the chickens simply fill a niche. The chickens serve as prey for Keys’ hawks and falcons, and they do a marvelous job of scorpion control.
