Charles Darwin Foundation to Continue Mangrove Finch Conservation Project

Puerto Ayora, April 8th of 2009.- The Charles Darwin Foundation (CDF) can continue its work to save the rare and endemic mangrove finch, thanks to an award of more than £150,000 (around 220 000 dollars) from the Darwin Initiative, a British organization which funds the protection of biological diversity. The project will continue to be led by Durrell Wildlife Conservation Trust, and are slated to fund two more years of a three year old project.

Since 2006, visiting experts from Durrell have collaborated with CDF scientists doing baseline studies and conservation work with the mangrove finch, once found throughout the coasts of Isabela and Fernandina islands but now limited to about 50 breeding pairs in two tiny patches of mangrove in northwest Isabela. "We found that [introduced] black rats were a major problem for the finches," said CDF Senior Scientist Birgit Fessl, who added that the rats prey on eggs and nestlings in large numbers. The team introduced an improved system of rat controls in the finch's range, and has seen significant declines in rat populations in the controlled areas.

Even better, these declines have been matched by improved survival of mangrove finch fledglings. This January, for the first time since the start of the project, year-old finches were observed in stands of mangrove between the two home patches. The CDF team believes that these yearlings have been forced to find new territory due to increasing population densities in their natal mangroves.

Those yearling mangrove finches will play an important role in the future of their species. With the two additional years of funding, CDF scientists will begin translocating young birds, who have not yet established home territories, to other sites on the east coast of the island, which has some 350 hectares of potentially suitable mangrove habitat. Because they are so close together, "the two current populations are really just one," and therefore vulnerable to a wave of disease, says Fessl. "We want a third population that can really sustain itself." The transplanted birds will be tracked to determine the new extent of their range, and the net of rat controls expanded. Additional research will examine threats from parasitic insects, and captive breeding may supplement the finches' numbers. Eventually, the CDF hopes to return the mangrove finch to nearly all of its former range.