"You don't hear any old boy iguana stories because they were never here before the 1960s," Johnson says. "In the last 10 years, Marco has seen a crazy increase." Besides Johnson and his colleagues ...

Since most iguana species live in the Americas, biologists have long debated how they could have arrived on the remote ...

The black spiny-tailed iguana has colonized Gasparilla Island, where they outnumber humans five to one, undermining sea walls ...