Iguanas return to a Galápagos island almost 200 years after Charles Darwin recorded them there

Iguanas were not Charles Darwin’s favourite species. In fact, he pretty much detested them. The famous naturalist once described Galápagos land iguanas (Conolophus subcristatus) as “lazy and half torpid” with a “singularly stupid appearance.” Ouch. Perhaps Darwin would have been more forgiving had he known that he’d be the last person to officially log a sighting of the reptiles on Santiago Island for the next 184 years.

A land iguana (Conolophus subcristatus). Image: Simon Matzinger

Since the time when Darwin dished out his unflattering description, the island’s iguana population has been completely eradicated by invasive predators like feral pigs. But now, thanks to a reintroduction initiative launched by the Galápagos National Park authority, the reptiles are making a comeback.

More than 1400 land iguanas were captured from neighbouring North Seymour Island late last year and have since been released onto coastal regions of Santiago, where a suitable ecosystem and abundance of food will hopefully make them feel right at home. From February, park officials along with experts from New Zealand's Massey University will be keeping a close eye on the iguanas to see if they are eating well and building nests. They’ll also be monitoring species like ants and rodents which are known to raid iguana nests.

A team releases land iguanas on Santiago Island. Image © Parque Nacional Galápagos/Facebook

Land iguanas being transported by Parque Nacional Galápagos and Island Conservation staff. Image © Parque Nacional Galápagos/Facebook

1,436 land iguanas were released onto Santiago Island. Image © Parque Nacional Galápagos/Facebook

In the past, the biggest threat to Galápagos land iguana populations came in the form of ravenous feral pigs. Introduced to the island by mariners and settlers in the 1800s, the predatory pigs feasted on young iguanas and eggs and – along with some help from cats, rats and dogs – were able to wipe out the entire population. Fortunately, the iguanas need not worry about those pesky pigs anymore: the island was declared officially pig-free in 2004 following a conservation initiative dubbed Project Isabela.

While Darwin may have had his reservations about land iguanas, the reptiles are endemic to the Galápagos Islands and play an important role in dispersing seeds and helping maintain the landscape. In addition to aiding the ecological recovery of Santiago Island, the iguanas may actually be better off in their new home as food resources, particularly cacti, are limited on North Seymour.

Header image: Peter Wilton