Finches were one of the many birds Darwin studied in the Galápagos Islands before publishing his monumental work on natural selection. Today, the mangrove finch is on the verge of extinction in the Galápagos. There are around 100 left, with just 20 breeding pairs. To keep the finches from disappearing altogether, the Charles Darwin Research Station and San Diego Zoo have engaged in a captive breeding program.
Recently, a third group of fledging mangrove finches were released on Isabela island. All birds are fitted with miniature tracking devices. Some returned to the aviary, but several finches released in past years have been seen in the wild. This showed finches raised in captivity are able to survive long-term.