Discovered by park guards in 1986 and formally described by Ecuadorian and Italian scientists in 2009, the Galápagos pink land iguana (Conolophus marthae) remains a species of intense interest for conservationists worldwide on account of its status as critically endangered.

The iguana, pink with black stripes, was not seen by naturalist Charles Darwin on his visit to the Galápagos Islands in 1835. It lives on Isabela Island’s Wolf Volcano, ranging from 600 meters (1,968 feet) above sea level to the 1,710-meter (5,620-foot) -high summit of the active volcano.

From Sept. 26 to Oct. 4 of this year, a team of Galápagos National Park personnel and scientists from the Galápagos Conservancy, a U.S.-based nonprofit, inspected the volcano to gauge the pink iguana’s population. The expedition, part of a program ongoing since 2022 to develop a long-term conservation plan for the reptile, observed eight pink iguanas—five females, two males, and one young iguana of indeterminate sex.

With its total population estimated at 300, the pink iguana is classified by the International Union for the Conservation of Nature (IUCN) as critically endangered. Experts say that because it is so small, the pink iguana population is subject to random fluctuation, or stochasticity, genetically and demographically, and is highly vulnerable to environmental shocks such as volcanic eruptions and drought.

Thus the effort to monitor and conserve the unique species, whose importance was spelled out 15 years ago in a paper published in the journal Proceedings of the National Academy of Sciences of the United States.

Product of isolation

The paper, coauthored by Ecuadorian and Italian scientists, described the pink iguana as the product of substantial genetic isolation, a relict lineage whose origin dates from a period in which some of the current-day Galápagos Islands had not yet formed.

The adult pink iguanas seen during this year’s expedition appeared in good condition, researchers reported. But the fact that only one juvenile and no newborns were seen points to a need for stronger conservation steps, particularly efforts to protect the pink iguana’s habitat from invasive species, according to experts with Galápagos National Park.

During the expedition, researchers noted the presence of 55 yellow iguanas (Conolophus subcristatus), which on Wolf Volcano coexist with pink iguanas. They also saw giant tortoises (Chelonoidis becki), also endemic to the islands.

Though the expedition’s main objective was to look for juvenile pink iguanas, the sighting of just one does not mean others are not present, Washington Tapia, director de Galápagos Conservancy, told EcoAméricas: “The climatic conditions of a severe drought did not help to locate them.”

Dry conditions are normal for the period in the high areas of the Galápagos. But experts say that in 2024 the archipelago faced greater-than-normal drought due to the La Niña weather pattern. They say increasing frequency of both El Niño and La Niña events appear to be the result of climate change.

Invasive species, however, are seen as the greatest threat to pink iguanas—especially feral cats. “This is indeed a problem,” Tapia says. “Our camera traps have shown that they [feral cats] are the main threat faced by juvenile iguanas, which is why it is necessary to reinforce the work to establish intensive control where the iguanas live.”

Serious cat problem

Controlling the cats would also benefit the yellow iguana, giant tortoises, birds and other species of the volcano. But eradicating feral cats is seen as nearly impossible, not least due to the island’s size and the enormous funding that would be required.

“A cat eradication project on such a large island would perhaps mean hundreds of millions of dollars, which obviously no one has,” Tapia says. “[That] is why intensive control is necessary in the living area of this species.”

Isabela Island covers 4,588 square kilometers (1,771 sq. miles) and represents roughly 60% of the land area of the Galápagos. It was formed by the union of six volcanoes, five of which, Cerro Azul, Sierra Negra, Alcedo, Darwin and Wolf, are active.

No attempt has been made to estimate the island’s population of feral cats, one of the most damaging invasive animal species. But experts say it is likely large given that cat paw prints and feces are seen not only on the volcano, but throughout the island and especially in its northern portion.

The 2022-2027 conservation plan for the pink iguana reports that the reptile inhabits a very small area of approximately 25 square kilometers (10 sq. miles) on the slopes of Wolf. It aims to establish an integral, long-term plan to promote recovery and long-term stability of the pink iguana. The plan is produced through a collaboration of organizations and institutions including Galápagos National Park, Galápagos Conservancy, the Jocotoco Conservation Foundation and the University of Rome Tor Vergata.