For almost 200 years, the Galapagos rail (also called the Galapagos rail, tern, or pachay) was missing from Floreana. Considered extinct on this small inhabited island in the Ecuadorian archipelago, this shy, almost flightless bird can still be found on some of the other islands. However, Charles Darwin was the last person to record a sighting of one on Floreana, when he visited the island in 1835. This year, following the removal of rats and feral cats from Floreana, the bird surprised conservationists with its unexpected reappearance on the island. How the lost bird returned is a mystery. Other threatened birds have also recovered, and some are even singing new melodies never before heard on the island. This change reveals new information about how a safer, almost predator-free environment can allow animals to experiment and innovate, according to scientists.

“The Galapagos rail was something I didn’t expect at all,” agrees Paula Castano, a wildlife veterinarian who works for Island Conservation, one of the organizations restoring Floreana.

“It just appeared” on Floreana, she says, adding that it may have remained a small, hidden, and unnoticed population all this time.

“(The rails) reappeared and now it’s very common to find them just walking around the island. You can hear them, you can see them, it’s incredible,” says Paola Sangolqui, a marine biologist with the Jocotoco Conservation Foundation, which is also part of the restoration project.

The rail’s reappearance is part of what scientists describe as an extraordinary return to life on Floreana, following the removal of invasive predators that had wreaked havoc. in native species.

“This is an instant explosion of these species, which until last year were considered very rare,” says Sonia Kleindorfer, a behavioral biologist at the University of Vienna, who, along with her team, has spent 20 years studying different species of finches on Floreana and other islands.

“It’s a remarkable and immediate comeback,” she adds.

In late 2023, after a decade of preparatory work, rats and feral cats were eradicated as part of a project to restore Floreana’s native ecosystem.

In 2025, bird counts revealed that several previously rare species—such as Galapagos doves, lava lizards, geckos, and the dusky-billed cuckoo—were observed more frequently, according to Birgit Fessl, senior research fellow for land bird conservation at the Charles Darwin Foundation, which is part of the Floreana restoration project.

“But the most exciting finding was the rediscovery of the Galapagos rail,” Fessl says. “This bird had not been recorded on Floreana for centuries; the only historical evidence of its presence was a specimen collected by Darwin himself.” Over the next few years, the plan is to reintroduce 12 species that existed on Floreana when Darwin visited, but which have become locally extinct. These include several bird species, as well as giant tortoises, and will be transferred from breeding programs and other islands where they survived. The project is led by the Galapagos National Park Directorate and implemented by Jocotoco Island Conservation, the Charles Darwin Foundation, and its partners. Even before the reintroductions, expected to begin this year, scientists studying Floreana say the island is already transforming in surprising ways, offering a unique, real-time glimpse into how ecosystems can recover. This adds to similar recovery stories seen elsewhere in the archipelago, such as Pinzon Island, where the giant tortoise was once on the brink of extinction due to rat predation of hatchlings, but is now thriving as hatchlings survive. A “classic case of evolution” “Nothing could be less attractive than the first impression (of the Galapagos Islands),” wrote Charles Darwin upon his arrival aboard the Beagle in September 1835. “Even we “We imagined that the bushes smelled unpleasant.”

Despite this unpromising start, the islands ended up having a huge influence on Darwin’s most important legacy: his theory of evolution. The birds he recorded—more than a dozen species of finches, now known as Darwin’s finches, and three species of mockingbirds—proved to be especially valuable clues.

“The Galapagos Islands are a beautiful classic example of evolution in action,” says Frank Sulloway, a historian of science and assistant professor in the psychology department at the University of California,Berkeley, an expert on Darwin's life and theories.

The islands, very close to each other, are home to different species of mockingbirds, land iguanas, lava lizards, and finches, explains Sulloway. Through a process known as natural selection, each species has adapted to its specific environmental conditions, which vary throughout the archipelago.

For example, the finches, known as Darwin's finches, have evolved from a common ancestor into species with different beaks adapted to different types of food.

(Although it was only after returning to London and consulting with ornithologist John Gould that Darwin reached these conclusions, says Sulloway.) Darwin also observed that rats, mice, and feral cats already posed a threat to island fauna around the world, including the Galapagos archipelago, and described these predators as a “great plague” introduced by humans. When a new predator, such as a rat, is introduced, the environment changes, forcing native species to adapt or become extinct, adds Sulloway. That's what happened in the Galapagos Islands, he says. “Just as Darwin imagined, once exotic species are introduced, you see how a stable system is disrupted, and then the principles of evolution begin to show themselves.” By the 2000s, invasive species had wreaked havoc throughout the archipelago, threatening native species and even causing the local extinction of some. Rats and cats devoured baby tortoises, adult birds and chicks, lava lizards and iguanas, and even snails. On Floreana, the Galapagos rail, the Floreana tortoise, and the Floreana mockingbird were among the lost species. A 2017 study showed that approximately half of the land bird species that originally lived on Floreana had disappeared. “The eradication of cats and rodents on Floreana began in late 2023,” Fessl says. Poison was dropped from airplanes and applied by hand. Researchers monitored the island’s birds before and after the operation (as a precaution, some island species were temporarily removed during the eradication). Another round of eradication, targeting the remaining rats and mice, is planned for late 2026. Experimental finch songs. The return of the lost rail wasn’t the only surprise for researchers. Perhaps most surprising is that, now that the predators are gone, some Floreana finches have begun to sing entirely new songs, Kleindorfer says.

Kleindorfer and his team had been studying Darwin's finches on Floreana and other islands in the archipelago for about 20 years, making 8,000 recordings of their songs, all of which belong to a limited repertoire. Originally, there were nine species of Darwin's finches on Floreana Island, he explains, four of which have become locally extinct in the last 100 years. The remaining populations on Floreana were aging, and all sang an unchanging set of songs. But this year, he heard the young finches suddenly experimenting with entirely new tunes. Other young finches skip syllables altogether and extract buzzes from the old songs, turning them into new melodies. What's going on? To explain the change, Kleindorfer begins by painting a bleak picture of what it was like to be a finch before the rats and cats were eliminated. “When we went to check the nests, we would often see a rat looking in,” he says. “They were in the nests, climbing the trees; the island was completely overrun with rats. They were even crawling around our tents.”

The medium tree finch was suffering especially, as its nest seemed to be at a height conducive to all the island's predators, she says, including native owls.