The new year rang in a landmark win for conservation in the Galapagos as land iguanas were reintroduced to Santiago Island for the first time in 184 years. One of the last people to record land iguanas, Conolophus subcristatus, on Santiago was the celebrated naturalist Charles Darwin in 1835. Soon after, the large, yellow lizards were wiped out by invasive species which monopolized essential food sources and preyed upon their eggs and young.
Land iguanas across the archipelago are forced to compete for vegetation with goats and donkeys and are at risk of predation by cats, dogs and feral pigs. Along with many other endemic species, land iguana populations are declining as they struggle with the introduction of new animals, and the lizards are listed as Vulnerable by the International Union for the Conservation of Nature.
Though invasive species have long posed a threat to the fragile ecosystems of the Galapagos, ecological restoration programs have been making significant strides. Organizations like the Galapagos Conservancy and Charles Darwin Foundation are working to eliminate invasive plants, insects and mammals. One initiative, Project Isabela, eradicated feral pigs, goats and donkeys from Santiago Island in the early 2000s.
On January 4, 2018, the Galapagos National Park Directorate and the international nonprofit Island Conservation transported 1,436 land iguanas from the neighboring North Seymour Island to Santiago, releasing the lizards in the coastal regions of Bucanero and Puerto Nuevo. These areas mimic the arid, scrubby habitats which land iguanas prefer, with plenty of sandy spots for females to lay their eggs. Galapagos National Park Director Jorge Carrión applauded the achievement as “great news for the Galapagos, for Ecuador and for the world.”
The relocation initiative was spurred by the depletion of cacti, the land iguana’s primary food source, on North Seymour Island beginning in 2016. With a population of 5,000 land iguanas and limited food availability, relocation was a sensible management measure, conserving resources for the portion of lizards remaining on North Seymour Island, while providing an opportunity for the species to thrive again on Santiago. As important seed dispersers, it is hoped that bringing these herbivores back en-masse will help restore the island’s ecological health. The Galapagos National Park Directorate and researchers from New Zealand’s Massey University will monitor the feeding and nesting habits of the reintroduced lizards to ensure they’re adapting well to the new changes in their environment.
According to Island Conservation, “other large scale restoration efforts are planned for other islands in the Galápagos…in 2020 invasive predators will be eradicated from Floreana Island, protecting 55 endangered species and allowing for the reintroduction of 13 locally extinct species, including the Endangered Floreana Mockingbird and Floreana Giant Tortoise.”
Meanwhile, land iguanas in Santiago will settle into their natural habitat, having returned home at last.