You usually hear them before you see them. There’s no mistaking the loud and often synchronized cacophony of caws from 11 ‘Alalā, also known as Hawaiian Crows, released into a Hawai‘i Island Natural Area Reserve last fall.
These birds, seven young males and four young females, represent what conservationists hope is the beginning of a recovered population of this critically endangered Hawaiian crow on the island.
‘Alalā have been extinct in the wild since 2002. Since the birds took flight from a remote forest aviary in September and October 2017, they have been under the daily, watchful eye of a monitoring team from San Diego Zoo Global.
In partnership with the Hawai‘i Department of Land and Natural Resources, the U.S. Fish and Wildlife Service and others, San Diego Zoo Global reared the ‘alalā at its Hawai‘i Endangered Bird Conservation Program centers on the Big Island and on Maui.
The ‘alalā are tracked daily by researchers monitoring signals from the lightweight radio transmitters each bird wears, as well as watching them with the naked eye or through binoculars. Their movements, their flights, what they eat, where they roost, their behaviors and virtually everything else about these birds is closely monitored and carefully recorded.
Of high interest to all the folks involved in The ‘Alalā Project is how the birds individually and collectively react to threats from predators. An initial release of ‘alalā in 2016 was halted and surviving birds were brought back into captivity after two were attacked by another native bird—their natural predator, the ‘Io or Hawaiian hawk. Prior to their release, the birds now living in the Pu‘u Maka‘ala NAR received extensive anti-predator training.
“Similar to any predator-prey interaction, there’s a lot that goes on that we don’t necessarily see—but the observations we’ve made indicate that the birds do identify ‘io as a predator and can take evasive action when needed,” explained Alison Greggor, Ph.D., a postdoctoral research associate with San Diego Zoo Global.
Last week, the monitoring team saw this in action: Two members of the project heard an eruption of ‘alalā alarm calls and heard quick wing flapping. A dark morph ‘io darted across an opening. Immediately after, a light morph ‘io crossed the opening with four ‘alalā following it or chasing it above the canopy. All four ‘alalā disappeared for about 15 seconds before the ‘alalā came back to the release area/feeder area.
“At this stage, we can’t be certain that the training is the crucial piece of the puzzle, but we like to hope that it helped,” Greggor said. “Actually being in the wild around predators, observing other forest birds and interactions with predators, is the best training they can possibly get.”
Another sign of how well they’ve accepted their new home in the forest is that they are being observed foraging more often for native fruits, instead of relying on feeders placed strategically outside the release aviary. Joshua Pang-Ching, the field operations manager for the project, noted: “In the beginning, they would spend much more time at or around the feeders. Now we see birds coming to feeders much less. We have seen an anecdotal shift in their use of the feeders and see birds daily foraging on the fruits and foliage of native trees.”
The supplemental feeders will remain in place for at least a year, to ensure that the newly “wild” birds have that extra helping hand they might need.
Greggor, Pang-Ching and Jackie Gaudioso-Levita, project coordinator of The ‘Alalā Project, are all hopeful for the birds’ future, given how this released group of ‘alalā is doing.
“We really learned a lot from the 2016 release,” Gaudioso-Levita said. “We made major revisions to our reintroduction strategy. These birds have adjusted very well to their forest home, and it’s just been really inspiring for all of us on the project to see and hear ‘alalā in the wild again.”
Not only can you hear them, “they’re very loud,” Gaudioso-Levita added. It’s a sweet sound for the many people who’ve worked for decades to get to this point. In time, researchers hope, the distinctive caw of the ‘alalā will again be heard loud and clear throughout the forest. Plans are underway to release additional birds in the NAR later this year.