Florida Scientists Are Running Around at Night Bashing in Iguanas’ Skulls

Florida Scientists Are Running Around at Night Bashing in Iguanas' Skulls

A team of scientists in Florida are on a three-month, $63,000 iguana-bashing spree.

The Florida Fish and Wildlife Conservation Commission contracted the 15-member crew from the University of Florida to develop a set of best practices for killing the big lizards, according to a March 9 report in the Sun-Sentinel. So far, bashing their heads in seems to be a winning method.

Conservation status

According to the International Union for Conservation of Nature (IUCN), iguanas are among the most endangered animals in the world. In the wild, iguanas’ numbers are dropping drastically due to loss of habitat and predators. The Fiji banded iguana, for example, is found on only two islands, and its population has dropped by 50 percent in the past 30 to 45 years.

The Galápagos pink land iguana is labeled as critically endangered. As of 2012, only one small population existed in an area of less than 25 square kilometers (9.6 square miles). Only 192 mature members were counted. The Utila spiny-tailed iguana is also considered critically endangered. It’s only found on the island of Utila, Honduras, and its population is believed to be less than 5,000.

Well-equipped team members sometimes use a captive bolt gun to destroy the critters’ brains. (Picture a mobile version of the device often used to kill cows in slaughterhouses.) But, the Sun-Sentinel reported, bashing their heads against the sides of solid objects, like trucks or boats, works just as well.

It’s so cold in Florida, iguanas are falling from trees

Given that the team is hoping their results will offer practical advice to homeowners, cracking some lizard skull against whatever hard object is handy might be a bit more practical than methods requiring bolt guns.

Iguanas, native to South America, are an invasive species in Florida, where they likely arrived via the pet trade, according to invasive iguana researchers. They feed on local plants and wildlife, the Sun-Sentinel reported, and may indirectly contribute to erosion. They also do weird things like freeze and fall out of trees when it gets too cold.

Head bashing may be “gruesome,” the researchers told the Sun-Sentinel, but it’s also the most humane of the effective methods they’ve come up with. Simply chopping the lizards’ heads off turns out to be less humane, and the traps the team set have thus far only captured raccoons. Working in teams of two, sneaking up on the lizards in the dead of night and bashing ’em seems to be the best method.

Florida Scientists Are Running Around at Night Bashing in Iguanas' Skulls

Not all Floridians seem thrilled with the project, which has reportedly killed 249 of the lizards so far. The Sun-Sentinel quoted a local veterinarian who suggested sedating and euthanizing the iguanas, and “Gary Fishman, a Boynton Beach resident, [who] says he’s killed more than 100 iguanas with a pellet gun to protect his landscaping,” who told the Sun-Sentinel that the iguana “needs to be eliminated,” but that he’s a bit uncomfortable with the whole head-bashing thing.

Iguana Facts

Iguanas are lizards identified by their stocky stature, the saggy skin on their throats and the spines that protrude from their heads, necks, backs and tails. Iguanas are popular pets and can live 15 to 20 years if cared for properly.

Emergency Food Supplies

The longest of the iguanas is the green iguana. It grows to between 5 and 7 feet (1.5 to 2 meters) long from nose to tail. The smallest of the group is the spiny-tailed iguana, which grows to 4.9 to 39 inches (12.5 to 100 centimeters) long. The heaviest iguana is the blue iguana. It can weigh up to 30 lbs. (14 kilograms), according to the San Diego Zoo.


Iguanas like warm temperatures because they are cold blooded. This means that the outside temperature is what keeps them warm since they have no way to regulate internal heat with their own bodies. These lizards are found in Mexico, Central and South America, the Galápagos Islands, on some of the Caribbean islands, Fiji and Madagascar. They typically live in tropical and subtropical forests, deserts and coastlines, according to the San Diego Zoo. The University of Florida also reports that there are iguanas running free in south Florida due to people setting their pets loose.


Overall, most iguanas are herbivores and only eat vegetation such as flower buds, fruits and young leaves. The marine iguana will get its meal by scraping algae from rocks in the ocean or by munching on sea weed, according to National Geographic. Pet iguanas and some wild iguanas enjoy worms, crickets and baby mice along with vegetation.


Iguanas are social creatures that eat and live together. Male iguanas are very territorial, though, and will fight other encroaching male iguanas. It is easy to identify male iguanas that are not dominant. They have broken and stubby spines that were damaged in battles with more dominant iguanas, according to the San Diego Zoo.

Since they don’t need to actively hunt for their food, iguanas are very laid-back creatures. Iguanas typically spend their days lounging in the sun to keep warm and from time to time they will get up for a snack. The green iguana will forage in the same spot every day, according to the Smithsonian.

Florida Scientists Are Running Around at Night Bashing in Iguanas' Skulls


Like most lizards, iguanas lay eggs, though the number of eggs varies, depending on species. The female rock iguana lays five to 20 eggs, for example, while the green iguana lays around 65 eggs.

Eggs are laid in a burrow in a warm, sunny area. The mother covers the eggs and then walks away. According to the San Diego Zoo, the burrow will stay a steady 77 to 89 degrees Fahrenheit (25 to 32 degrees Celsius), which incubates the eggs until they hatch. The baby iguanas are completely on their own for the three years it takes to fully mature because their mother never returns. Many young never make it to maturity.

Mary Greeley News

credit: https://www.livescience.com/61992-iguana-skull-brain-bash-flordia.html