The mangrove finch is one of 17 species of Darwin’s finch and one of the rarest birds in the world. With only around 100 individuals alive today, mangrove finches are the most endangered birds in Galapagos. These finches are not part of a wider, fragmented colony, but represent the entire world population.
Lead Project Partners
The mangrove finch in numbers
small areas of mangrove provide the last refuge of the mangrove finch
hectares of habitat remain
birds were left in 2014
The estimated current population
Once occupying a number of mangrove sites on Isabela and Fernandina, these tiny brown birds, endemic to Galapagos, are now only found in two small patches of mangrove forest on Isabela – Caleta Black and Playa Tortuga Negra – with a combined size of just 32 hectares.
Habitat loss combined with the presence of introduced black rats and the invasive parasitic fly, Philornis downsi, whose larvae suck the blood of nestlings, often resulting in the chicks’ death, has driven the species to the brink of extinction.
Due to the extremely low numbers of mangrove finches remaining, population monitoring is crucial to detect changes to population size and distribution and to determine the effectiveness of management actions.
Additionally, since 2019, the field team has observed an apparent die-back of black mangroves, the favored nesting tree of the mangrove finch, in their remaining habitat. Environmental factors already have a huge impact on mangrove finch reproduction and nesting success; for example, dry conditions in the breeding season can limit food availability and the number of females obtaining breeding condition or even abandoning their chicks. Baseline monitoring to understand environmental trends and mangrove health are vital for mangrove finch conservation.
How we’re tackling it
Thanks to the extraordinary conservation efforts of the Mangrove Finch Project team, mangrove finch population estimates have grown significantly from 60 birds in 2014 to 100 birds today.
Each year, researchers spend two to three months in the field during the breeding season, collecting important population data, such as the number of breeding pairs and re-sightings of these captive-reared individuals, and undertaking vital conservation measures including supplementary feeding of chicks and deploying baited rat traps.
Between 2014 and 2018, the team focused on hand-rearing chicks at the Charles Darwin Research Station and re-releasing them into the wild to give them a head start in life, and this ‘head-starting’ approach boosted the population by 39 fledglings. However, this was a hugely labour-intensive and expensive method, and in recent years, the team has been focusing on Philornis control in the wild. This includes injecting wild nests with an insecticide, which needs to be delivered by a highly skilled tree-climber, and trialling use of feather dispensers treated with an insecticide to see if breeding pairs will use these feathers as nest building materials.
The team have also been collaborating with the Smithsonian Institute to set up a mangrove monitoring plan to better understand the drivers of change within mangrove forest systems, particularly in the context of climate change. They are using baseline data collected on mangrove forest health to confirm the scale of mangrove dieback, which will ultimately help inform conservation management actions to best protect this Critically Endangered bird.
The multi-institutional Mangrove Finch Project is focussed on increasing our understanding of the biology and ecology of these birds and the threats they face. Learnings from finch captive holding trials on Floreana island and the reintroduction of woodpecker finches to Pinzon island will also be vital for informing mangrove finch conservation plans.
The Mangrove Finch Project is a bi-institutional project carried out by the Charles Darwin Foundation and the Galapagos National Park Directorate in collaboration with San Diego Zoo Global, Auckland Zoo and Durrell Wildlife Conservation Trust. The project is supported by Galapagos Conservation Trust, Club300 Bird Protection, Leona M. And Harry B. Helmsley Charitable Trust, Marguerite Griffith-Jones, GESS Charitable Trust, Decoroom Limited, Holbeck Charitable Trust, and Friends of Galapagos Switzerland.
Mangrove Finch Project update
Mangrove Finch Project update
Mangrove Finch Project Update
How you can help
With your help, we can safeguard the future of these Enchanted Isles.
Pinzon island restoration
"In 2012, Pinzon island was cleared of invasive rats. Ten years later, there are promising signs of ecological recovery."
Learnings from Pinzon will be vital for supporting reintroduction plans for songbirds on Floreana island and conservation plans for the Critically Endangered mangrove finch.
"Floreana is the sixth largest island in Galapagos, and used to be home to some of the most iconic species in the Archipelago."
We are supporting partners to undertake one of the most complex eradication projects ever conducted on an inhabited tropical island, with the ultimate aim of reintroducing locally extinct species.