The lizard that could rewild Isabela Island
The Pink Iguana has the best view of the Galápagos. These rose-colored reptiles live at the top of Wolf Volcano on Isabela Island. Their habitat, around the ring of the caldera, is so high they are usually above the clouds. At 5,600 feet (1,707 meters), Wolf Volcano is the tallest peak in the Galápagos archipelago. But these pink-and-black lizards are living on the edge. Wolf Volcano is still active and its most recent eruption was in 2016. The next one could take out the small population of between 200 and 300 Pink Iguanas living on it.
On top of a smoking volcano
A volcano that could erupt at any time isn’t the only threat to the Pink Iguana’s survival. Invasive species brought to Isabela by humans, especially cats, have hunted the iguanas to near extinction. Hatchlings and young iguanas are the most vulnerable. They are not big enough to fend off attacks from cats. All of the Pink Iguanas living on Isabela are adult iguanas and they are in desperate need of some babies surviving to replenish the aged population. Scientists estimate that only about half of the Pink Iguanas on the island are still capable of reproducing.
Conservationists in the Galápagos are working to take some of the heat off of Pink Iguanas. Island Conservation, working under Galápagos National Park and with support from Re:wild, is creating a conservation breeding program for the lizards. They plan to move some Pink Iguanas into captivity where they can breed and their babies can safely hatch away from cats. When the baby iguanas are large enough, likely between 3 and 4 years old, they can return to the wild. The head-starting program will help the iguanas' population rebound faster. In the meantime, conservationists are working to control the cat population on Isabela, so future generations of wild iguanas can successfully reproduce.
Conservationists are hopeful that the parallel breeding program and eradication of invasive species will be successful. “Recently, there’s been significant work in translocations and [breeding] with Galápagos Land Iguanas from Seymour Norte Island across to Santiago Island, explains Paula Costaño of Island Conservation.
Rewilding Isabela Island
When Pink Iguanas do return to Isabela and their population rebounds, conservationists expect that the island will be transformed. The iguanas are ecosystem engineers and are critical to plant regeneration. As they forage, eating plants and fruits, they disperse seeds allowing native plants to grow. And those plants don’t just provide food, they also provide hiding places for young iguanas and other species to avoid predators, like owls.
Older than the Galápagos
Pink Iguanas have been living in the Galápagos for millions of years. They evolved 5.7 million years ago, which means they are older than Isabela Island itself. Scientists are not sure where they originally came from, but think it’s likely that they may have lived on an island that is now submerged under water, pulled down as the Nazca tectonic plate crashes into South America.
Despite being older than some of the Galápagos Islands, scientists didn’t discover the Pink Iguana until the mid 1980s. Even after finding the iguanas living on top of Wolf Volcano, they didn’t determine that the small population was a completely different species from the Galápagos Land Iguana until 2009. Their colors easily distinguish them from the four other iguana species in the Galápagos. The pink skin that covers their backs and heads doesn’t actually have any pigment in it. The pink color comes from the blood vessels underneath their skin.