Six endangered palila birds, hatched and raised at the Keauhou Bird Conservation Center, took flight in a restored Hawaii island forest for the first time in their lives earlier this week.

The release was a milestone capping a multi-year effort by several collaborators, including the state, San Diego Zoo Global and U.S. Fish and Wildlife Service, who have been working together to save the Native Hawaiian forest bird species.

“This milestone shows how we can avert the tragedy of extinction when we use years of research to guide conservation decisions,” said Koa Matsuoka, a senior research coordinator at San Diego Zoo Global, in a news release. “Taking a ‘one plan approach’ to conservation, field work, and managed care, has allowed us to move forward with saving the palila. Our reintroduction efforts with this species can be a model for other efforts to fight extinction in the future.”

Palila, or Loxioides bailleui, are the last surviving members of 16 species of finch-billed, seed-eating birds in the main Hawaiian islands. The songbirds were once found on Kauai and Oahu, but are now found only in a small, isolated area on the upper slopes of Mauna Kea.

Only about 1,000 are left in the world, according to Chris Farmer, Hawaii Program Director of the American Bird Conservancy, one of the collaborators of the project. The release is an attempt to establish a second population at Mauna Kea.

The six birds were outfitted with radio transmitters attached to a backpack-style harness before their release into the Pu‘u Mali Restoration Area on Mauna Kea’s northern flank so researchers can track them.

They were housed as pairs in three separate release aviaries for the past few weeks, according to state officials, fed daily, and under nearly constant observation. To help them adjust to the wild, researchers have placed feeding stations within the release area.

Like most Native Hawaiian forest bird species, palila have struggled due to habitat loss and degradation, and introduced predators such as cats and mongooses. Hoofed animals such as sheep and goats have destroyed mamane, a slow-growing native tree species that the palila rely on for about 90% of their diet year-round.

Since 2008, restoration work at Pu‘u Mali has brought back the mamane and other sub-alpine dry forest species, with thousands planted, along with predator control, to assist with the recovery of the species.