Conservation status: IUCN Red List – Critically Endangered
Threats to survival: Nestling parasitism by introduced botflies
One of the Rarest Birds in the World
The mangrove finch is one of fifteen species of Darwin’s finches and one of the most endangered birds in the world. It is found only on the Galápagos Islands and once occupied a number of mangrove sites on the islands of Isabela and Fernandina. Unfortunately, the habitats where the finches live have declined severely throughout the last 100 years. All of the surviving birds are now restricted to only one small mangrove patch on Isabela, with only 40-60 individuals remaining today.
A Headstart on Survival
The primary threat to mangrove finches is the loss of their nestlings through parasitism by the larvae of the introduced botfly Philornis downsi. Together with our partners, San Diego Zoo Global began coordinating an experimental program in 2014 to apply headstarting as a conservation strategy. First, we established a propagation facility at the Charles Darwin Research Station (CDRS) on Santa Cruz Island. We then developed protocols to artificially incubate eggs and rear chicks, release juveniles, and train local staff in these efforts. Our goal in headstarting chicks was to increase reproductive output, overcome the impact of botflies, and add new recruits to the dwindling wild population.
Back to the Wild
Three nest collection trips were made to the mangrove forest on Isabela, where the CDRS team collected 21 eggs and three chicks and successfully transferred them more than 100 miles by helicopter to the research station. Once there, chicks were treated to remove the parasites and the rearing process was started. In the first year, 14 mangrove finches were successfully reintroduced to the wild. Today, this important work is being carried forward by the San Diego Zoo Global animal care staff who were part of the original team. The ultimate goal of the recovery program is to find solutions to permanently eliminate the threats that led to the dramatic decline of the finches and restore the population to a level that will be viable over the long-term.