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, with a combined size of just 32 hectares. The multi-institutional Mangrove Finch Project has focused on increasing our understanding of the biology and ecology of these birds and the threats they face.
Since 2014, GCT has partnered with the Charles Darwin Foundation in a bid to save this critically endangered species. Habitat loss combined with the presence of introduced black rats and the invasive parasitic fly, Philornis downsi, whose larvae sucks the blood of nestlings, often resulting in the chicks’ death, has driven the species to the brink of extinction. However, thanks to the extraordinary conservation efforts of the Mangrove Finch Project team, including rat control, intensive hand-rearing of chicks and Philornis control in the wild, the population estimates have grown significantly from 60 birds in 2014 to 100 birds today.
Hand-rearing at the Charles Darwin Research Station and re-releasing into the wild means that the project team has been able to give the chicks a head start in life. 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. Other measures to protect these birds are in place, including treating nests with insecticide to kill P. downsii larvae in the wild.
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. In 2018 and 2019 in particular, a lack of regular rainfall resulted in a low number of breeding pairs and birds having reduced body mass. To make matters worse for the mangrove finch, in recent years their preferred mangrove species for nesting, the black mangrove, is in decline. Work is ongoing in 2020 to understand the cause, but this only adds to the need to raise funds to help protect this critically endangered bird.
To find out more about the project, please visit our blog for project updates.
You can listen to the song of a male mangrove finch, recorded by the Charles Darwin Foundation, below.
How you can help
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, Leona M. And Harry B. Helmsley Charitable Trust, Marguerite Griffith-Jones, GESS Charitable Trust, Decoroom Limited, Holbeck Charitable Trust, and Friends of Galapagos Switzerland.