Restoring Mangrove Finch Populations

Restoring Mangrove Finch Populations
PAST

PROJECT:

Mangrove Finch Captive Rearing Program

PARTNER:

Charles Darwin Foundation

STATUS:

Funded by GC in 2014; Charles Darwin Foundation is continuing with the project.

Mangrove finch

Photo by F. Cunninghame, CDF

 

Background

Researchers from the Charles Darwin Foundation (CDF) and the San Diego Zoo Global (SDZG) have implemented a captive rearing program for mangrove finches in an attempt to begin to restore their population. The primary threat to the mangrove finch is the invasive avian parasite Philornis downsi, which lays its eggs in the nests of finches. Philornis larvae then feed on the tissue and blood of nestlings, causing high mortality of the young birds.

The mangrove finch (Camarhynchus heliobates) is the bird species most threatened by extinction in the Galapagos Islands, and is classified as “Critically Endangered” on the International Union for the Conservation of Nature’s (IUCN) Red List of Threatened Species. There are less than 100 mangrove finches left in existence, all in two large mangrove forests on the western coast of Isabela Island. The captive rearing project provides the mangrove finch chicks with a Philornis-free environment after hatching, ensuring they are not attacked by the voracious larvae.

In early February 2014, 21 eggs and three newly hatched chicks were collected from wild nests in the mangrove forest on Isabela and transported to the newly-created incubation and hand-rearing facility at the Charles Darwin Research Station (CDRS). This is a quarantine facility, which minimizes the chance of nestlings being infected by disease. Baby Finch being fed with tweezersLater in February, the first mangrove finch chick ever to hatch in a laboratory was born at the CDRS, and more than a dozen chicks hatched shortly thereafter. Once they had been hand-reared — which required up to 15 hand-feedings a day — the young birds were returned to an aviary on western Isabela before being released back into the mangrove forest and monitored by the field team.

In March 2014, CDRS scientists took the first group of young finches to the aviaries, and in early May, 15 finches were successfully released from the aviaries back into their natural habitat. The field team reported that they have been adjusting well to their native home.

Read more about the release. In March 2015, the project team successfully collected an additional 30 eggs from the wild and began the process of hand-rearing them.

Read more about the captive rearing process in the program’s second year, and read the 2015 project results.

Watch a photo slideshow of the mangrove finch program in action.

Read the May 2015 journal publication: Philornis downsi, An Avian Nest Parasite Invasive to the Galapagos Islands, in Mainland Ecuador by Bulgarella et. al, Annals of the Entomological Society of America.