For the first time ever, conservationists in the Galapagos Islands have hand-reared a species of bird in an effort to save it from impending extinction. With an estimated 80 individuals left in the wild, the mangrove finch is one of the most critically endangered species in the islands and one of the rarest birds in the world. The finch’s remaining range is comprised of just 75 acres of forest on Isabela Island. In addition to habitat loss, it faces other grave threats including an invasive fly species called Philornis downsi, the larvae of which feed upon and kill the birds’ nestlings.
In February, a team from the Charles Darwin Foundation (CDF) collected eggs in the wild, artificially incubated them, and raised the chicks in captivity for four weeks, until they were capable of feeding on their own. The chicks were then returned to the forest where they lived in specially constructed pre-release aviaries so that they could begin to adapt to their natural environment in relative safety. The team filled the aviaries with dead logs, leaf litter, branches, and seeds fruits containing caterpillars so that the young birds could learn to find food on their own.
In April and May, the field team opened the aviary doors and released all 15 birds into the wild, but not before fitting them with tiny transmitters. The team has managed to locate eight of the 15 birds since their release and it is believed that the others have moved out of the immediate mangrove forest habitat. No mortalities have been confirmed so far.
While obviously a huge step in the right direction, hand-rearing alone may not be enough to save the mangrove finch. Small populations of geographically isolated birds are notoriously susceptible to environmental threats, which is why urgent efforts are underway at the CDF to control invasive species such as Philornis downsi.