Like Hawaii’s endangered alala, the Puerto Rican parrot was on the edge of extinction and being bred in captivity for reintroduction into the wild.
And like the Hawaiian crow, an initial release did not go well, with similarly disastrous results: Six of
22 parrots were attacked and killed by hawks in that first week in 2006, compared with two of five alala a decade later.
Despite the early setback in Puerto Rico, 100 or more wild parrots are now thriving in the Rio Abajo State Forest following subsequent releases.
Today, Hawaii officials are looking to their counterparts in Puerto Rico for advice as they seek to rebound from December’s aborted alala release, when three birds perished in the first week of freedom — two
apparently picked off by the io, or Hawaiian hawk, and another that weakened after getting caught in a winter storm, according to necropsies.
The remaining two juvenile males were brought back into captivity, rejoining the nearly 130 birds that represent the entirety of the species. Plans for the release of a second group of juvenile females were shelved.
Extinct in the wild since 2002, the Hawaiian crow is preserved only at the Keauhou and Maui bird conservation centers managed by San Diego Zoo Global’s Hawai‘i Endangered Bird Conservation Program.
The zoo has joined the state Department of Land and Natural Resources, the U.S. Fish and Wildlife Service and Hawaii island land managers in the ‘Alala Project, which aims to return the alala to its traditional habitat in the forest of the Big Island.
Following the ill-fated first release, the project invited Tom White, a U.S. Fish and Wildlife Service biologist with the Puerto Rico Parrot Recovery Program, to travel to Hawaii to help evaluate the effort and offer guidance and technical assistance.
His advice?
Conduct more intensive predator-aversion training. That’s how the outlook improved for the Puerto Rican parrot following the initial release at Rio Abajo, White said.
“Needless to say, subsequent groups released the following years were all subjected to aversion training, and we did not see any similar episodes of high mortality with the other Rio Abajo releases,” White said in an email.
Hawaii officials are now aiming to conduct their second release in the Puu Makaala Natural Area Reserve near Hilo in late summer or early fall, according to Jackie Gaudioso-Levita, coordinator of the ‘Alala Project.
That will allow enough time to implement changes needed to give the birds a better chance at survival, she said. Among those changes is more intensive predator-aversion training.
In Puerto Rico, trainers teach their release candidates to fear, avoid and hide from fierce red-tailed hawks. They employ a number of techniques, including playing hawk shrieks while the predator’s silhouette passes overhead and staging simulated attacks by a trained hawk in full view of the parrots.
Observing the reaction to the danger helps biologists determine which birds might best survive in the wild.
Gaudioso-Levita said the project is modifying the outdoor flight aviary to better implement some of the new training techniques.
There are also plans to move the release site a couple of miles to a location higher on the mountain — and hopefully away from the typical range of the Hawaiian hawk.
Gaudioso-Levita said biological surveys of the io — also an endangered species — indicate fewer of them venture above the
5,500-foot level.
To more precisely locate the release site, officials plan to explore other areas of Puu Makaala and broadcast the shrill, high-pitched call of the io. The predator is territorial, she said, so if there are no responses to the calls, it might indicate a safer locale for the crows.
Another planned change is to release a dozen alala at the same time, rather than the previously planned dozen in two separate stages. Releasing the group together from the beginning, she said, will allow more social interaction, communication and potential for warning calls when any hawks fly into the vicinity.
Gaudioso-Levita said it’s important to remember that predator mortality is “not at all uncommon” in the initial stages of reintroduction programs.
“More important are the lessons learned and to keep in mind the bigger picture,” she said.
Successful reintroductions, such as the nene and the California condor, took decades to achieve success, with many ups and downs and bumps and bruises along the way, she said.
“The recovery of nene took over five decades of conservation actions to achieve, and while there are now over 3,000 birds in the wild, nene populations still require active management to persist,” Joey Mello, Big Island wildlife program manager with the state Division of Forestry and Wildlife, said in a press release.
Donna Ball, a Fish and Wildlife Service biologist and member of the advisory Alala Working Group, said that although she wasn’t surprised by what happened to the first release, she didn’t really think it would happen so quickly.
Still, she said, it’s important to manage expectations.
“You’ve got to be realistic. You can’t expect overnight success,” she said. “In the 1990s we had only a handful of birds. We stopped (releasing them) because there weren’t enough to release. Now there are birds and we’re doing our due diligence.”
Studies indicate that fewer hawks are found in the densest forest areas. By releasing them in the highest-quality areas, biologists are giving them a better shot at survival, she said.
