Wildlife control actions go wrong when they lack justifiable objectives, fail to rely on a science-based approach, and fail the test of humaneness. We’ve seen a brutal example of this playing out in South Florida for the last few weeks, courtesy of the Florida Fish and Wildlife Commission, which has hired contractors from the University of Florida to go around trapping iguanas and killing them with bolt guns or by smashing in their heads. It’s emblematic of the shabby approach that Florida wildlife officials have demonstrated time and time again when it comes to the problem of invasive species in their state, and they need to adopt a new paradigm, one that’s scientific, practical, and humane.
Florida faces a serious invasive amphibian and reptile challenge, caused primarily by the pet trade. More than 500 non-native fish and wildlife species have been observed in the state, and most of these got into Florida habitats through escape or unauthorized release from pet owners. As a result, there are Burmese pythons in the Everglades, Nile monitor lizards in Cape Coral, and Cuban treefrogs in more than 36 Florida counties.
It’s the green iguana that is being targeted by the hired guns. This is one of three members of the iguana family established in mainland South Florida (the Mexican spiny-tailed iguana and the black spiny-tailed iguana are the others). Green iguanas have been in South Florida since the 1960s, likely rafting in from native home ranges as a result of hurricanes and other natural events. In the 1980s, the green iguana was top of the charts for the pet reptile trade, and as a result its population rocketed. Then, predictably and inevitably, pet owners began releasing iguanas into the wild when they got too large, too aggressive, or too sick. These former pets, along with escapees and refugees from exotic animal shipments, expanded their hold on areas around southern Florida’s bays, canals, ponds, impoundments, and drainage ditches.
Iguanas are long-lived and fertile, and in the absence of predators and competitors for food, they are not going away anytime soon. In fact, they may expand northward into the state. But trying to reduce their populations without addressing the root causes of iguana conflicts and population expansion will only result in a continuous cycle of killing. No invasive reptile species has ever been eradicated through such management efforts.
What Florida urgently needs is a ban on the purchase, sale, and possession of potentially invasive species in the state, like iguanas, but as of now the state still allows the sale of green iguanas and does not require a permit to possess green iguanas as personal pets, including captured iguanas.
Killing iguanas by banging them against a truck or boat is neither humane nor acceptable. What’s more, Florida is making things worse by classifying the iguana as a pest or a nuisance. This encourages members of the public to start their own killing campaigns, often using brutal methods. Already, at our South Florida Wildlife Center, we have seen green iguana patients shot with crossbows, pellet guns, and hog-tied with their limbs cut off.
The Florida Fish and Wildlife Commission needs to adopt a comprehensive and humane program for managing conflicts with iguanas, one that takes into account the biology, habits, and ecology of these species. The best programs are those that combine reproduction inhibition methods, including egg removal with habitat modification and other exclusionary techniques, and public education. Such an approach is not only more humane than killing or depopulation programs, but more efficient and cost- effective in the long-term. What Florida is doing now brings to mind the wry definition of insanity you’ll see in an internet meme now and then: “doing the same thing over and over again but expecting different results.”