The Galápagos rail, a small, black, ground bird, hadn’t been seen on Floreana Island in the Galápagos since 1835, when Charles Darwin first described it. That changed recently when researchers monitoring birds on Floreana recorded the rail at three different locations. These new sightings after 190 years are likely the result of efforts to eradicate invasive species on the island.
The Galápagos rail (Laterallus spilonota) is a largely flightless bird and as such is particularly vulnerable to predation. The bird is found on several of the Galápagos islands, where Darwin developed his theory of natural selection. But on Floreana, the rail wasn’t seen again after Darwin’s initial visit. Invasive species like rats and cats that can eat bird eggs and adults were, however, on the rise.
“Potentially some of the species like the rodents came with pirates, with some of the people that settled on the island, and even potentially when Darwin came,” Paula Castaño, native species manager with the NGO Island Conservation, told Mongabay in a video call.
Invasive species on Floreana have caused the extirpation of many native species, including several bird species and giant tortoises.
To improve conditions so native animals can return, a team including Island Conservation and the Charles Darwin Foundation began a campaign to eradicate rats using toxic chemicals. Castaño said they took special care to protect native species that might be at risk of exposure to the poison, especially birds of prey that could eat poisoned rats.
For instance, to mitigate risk to the Galápagos short-eared owl (Asio flammeus galapagoensis), “part of the of the population was brought in captivity and once the island is ready for that species to come back, we will be releasing that population again,” Castaño said.
They also worked with the local community on a campaign to encourage people to keep pet cats inside. Domestic cats are thought to be the single biggest nonnatural killer of birds worldwide.
Residents of the island have been supportive of the eradication program and excited to see the Galápagos rail once more. “I was really moved when they told me it had been seen, and I have also seen it myself now,” longtime resident Claudio Cruz told Mongabay in an email.
“Hopefully, other birds that we once thought were lost will start to reappear again,” Cruz added.
The project coordinators are actively monitoring 12 different native species to see if they return to the island now that both rats and cats have largely been removed.
It’s possible a small population of Galápagos rails may have always been present on Floreana but unnoticed until their population grew once invasives were removed. Alternatively, they may have come from another island. They’re strong swimmers but don’t fly well so, if true, it would be impressive, Castaño said.
“Nature has a way to amaze us all the time,” she said.
Banner image of a Galapagos rail courtesy of Island Conservation.
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