Originally brought to the island as pets, iguanas have undergone a population explosion in the past few years. Their numbers have actually increased to the point that the invasive lizards may now outnumber the human population of the Caribbean island.
In fact, according to National Geographic reports, iguanas have become such a menace that they have started causing damage to the agriculture and infrastructure of the territory, wreaking havoc on air traffic control and causing millions of dollars of damage. Since the creatures don’t have any natural predators, residents are scrambling to find a way to address the problem.
“These guys are big. They can grow up to six feet long with their tails,” Rafael Joglar, a biology professor at the University of Puerto Rico, told Nat Geo. “Iguanas will nest very close to the road and they actually are making up to thirty different caves underneath the roads. So when there is a vehicle crossing the road with several passengers, the road will collapse.”
“These animals are causing air traffic delays. They’re eating crops and causing damage in general,” added Carlos Rodriguez from the ecological advocacy group Para la Naturaleza. “That’s why they call it a green plague. And why is it a plague? Cause it’s an invasive species. These guys came here through the pet trade. They’ve dispersed throughout the island.”
More than four million strong
Experts report that several factors have caused the iguanas to spread throughout Puerto Rico, including the climate. The island territory has a tropical climate featuring year-round warm temperatures and defined wet and dry seasons, not unlike Central and South America. This leads to patches of open land where the iguanas can nest, with each critter lying up to 75 eggs per year.
“Now in Central and South America you would have natural predators,” Rodriguez said. “Fifty two to be exact. Here in Puerto Rico, we haven’t had an iguana species living on the island for more than five hundred years. So that means that green iguanas are unhindered. They have a lot of vegetation to eat, a lot of land to nest in, and very few predator pressures.”
Joglar added that the iguanas “were here for over forty years and nobody noticed them. And then all of a sudden they became very common, very abundant and they started to interact with people and interact with our ecosystems here in Puerto Rico. And they have become a problem.”
Rodriguez explained that conservationists have been trying to get rid of iguana eggs and had been able to eliminate roughly 13,000 from the population since 2008. While that might sound like a large number, they might have to continue doing this for the next 15 to 20 years, as there are an estimated four million iguanas on the island, or at least one per person.