A critical iguana species has been reintroduced to a Galapagos island: NPR

The Galápagos land iguana is making a comeback on Santiago Island. Conservationists say the species shows signs of successful reintroduction.

Direction of the Galapagos National Park


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Direction of the Galapagos National Park


The Galápagos land iguana is making a comeback on Santiago Island. Conservationists say the species shows signs of successful reintroduction.

Direction of the Galapagos National Park

A species of iguana that went extinct almost 200 years ago on one of the Galápagos Islands appears to be making a comeback, with the help of a team of conservationists.

The last person to spot a Galapagos land iguana on the island of Santiago in Ecuador was Charles Darwin in 1835. When an expedition team from California arrived in 1906, the iguanas were nowhere to be found.

And although this type of iguana can still be found on the other Galápagos Islands, it is thought to have disappeared from Santiago within the last 187 years – until now.

A team of scientists and park rangers discovered new lizards of varying ages during a walk on the island in late July, suggesting the species has been successfully reintroduced. And according to Jorge Carrión, director of conservation at the Galápagos Conservancy, the ecosystem is thriving.

The proof is in the details, he explained. Seeing lizards of different ages and encountering unmarked specimens means the iguanas are breeding in their natural environment.

Prior to joining the Galápagos Conservancy, Carrión worked for the Direction of the Galapagos National Park, custodians of the ecosystems and resources of the islands. The GNPD is also the lead authority for the iguana reintroduction project, with funding and assistance from the Conservancy.

He said the collaboration has released more than 3,000 land iguanas on the island since January 2019.

Conservationists decided to reintroduce the land iguana after carefully considering how a return of the species would affect the ecosystem. These lizards are what is called an engineered species, like the Galápagos giant tortoise, in that they play a vital role in maintaining a healthy balance in an ecosystem.

As the main herbivores of the Galápagos Islands, land iguanas and turtles spread seeds across the landscape and help model plant communities, Carrión explained. Their movement patterns also create open spaces used by other animals.

“These kind of species are essential for the ecosystem in general,” Carrión said. “In this case, it was the rationale for the reintroduction of land iguanas, for [return] the natural dynamics of the island of Santiago. When engineer species are not present, many imbalances occur in the ecosystem.”

Iguana monitors inspect the population for new lizards of varying ages, indicating that the species is reproducing on its own.

Direction of the Galapagos National Park


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Direction of the Galapagos National Park


Iguana monitors inspect the population for new lizards of varying ages, indicating that the species is reproducing on its own.

Direction of the Galapagos National Park

What caused the iguanas to go extinct?

The Galápagos land iguanas are believed to have been wiped out by invasive species including feral pigs, cats, goats and donkeys. These unwanted animals have been introduced to some islands, including Santiago, by whalers and other sailors. They wreaked havoc on the ecosystem, devouring plants that other species relied on, and some even ate iguanas.

This This is why scientists had to rid the island of non-native animals before the iguanas could be reintroduced. This was accomplished over a period of nine years thanks to the Galápagos Conservancy’s Isabelle Projectcompleted in 2006.

Carrión said he and his colleagues believe they have learned an important lesson from the reintroduction of land iguanas: if you remove the source of the ecological disturbance (the invasive species in this case), the ecosystem can recover and regain its natural dynamics.

The Galápagos Conservancy and the National Park Authority are also working together to reintroduce the giant tortoise on another island. The native tortoise has been extinct on Floreana Island since the 1800s, according to the Galápagos Conservancy, and reintroduction and breeding efforts began in 2017.

The ecosystems of the Galápagos Islands are home to some of the most fascinating plants and animals in the world. The islands were made famous largely thanks to Darwin and his expedition of 1835, according to the Conservatorywhich led to his theory of evolution by natural selection.

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