This small brown bird, one of Charles Darwin’s famous finches, was found in the past in dense mangrove swamps on two of the Galápagos Islands, Fernandina and Isabela. However, it has now disappeared from Fernandina, and less than 100 birds are thought to remain in three tiny mangrove patches on Isabela.
The finch prefers mangrove separated from the sea with tall trees and plenty of leaf litter and dead wood where it can search for its invertebrate prey, and does not live in other more typical types of mangrove swamp. This means loss of mangrove habitats is even more damaging to the remaining birds.
A parasite found in all the finches’ nests may be affecting the survival of chicks, and introduced predators such as rats, cats and smooth-billed anis can devastate nests in the breeding season.
There has been a steady decline in the number of breeding pairs left, and so, in 2005, urgent action was called for. Durrell is now collaborating with the Charles Darwin Foundation (CDF) and Galápagos National Park on a project funded by the UK government’s Darwin Initiative. While work goes on to assess the remaining wild populations, a trial captive breeding programme is being established at the CDF field station on the island of Santa Cruz.
As we don’t want to take the risk of moving mangrove finches from their home island, particularly when we don’t yet know what management techniques will suit them best, we are starting by working with the closely-related woodpecker finch. A member of our bird staff has been seconded to the Galápagos to help set up the programme.