This alala, Hawaiian crow, hatched on May 31 at San Diego Zoo Global’s Keauhou Bird Conservation Center, making it the sixth of its species to hatch this year and bringing the entire population to 100 birds. (Rosanna Leighton/Special to West Hawaii Today)
Eight alala — the world’s most endangered crow — have hatched so far this year in a captive Hawaii bird breeding center, bringing the entire population to more than 100 birds.
It’s a significant population boost for a species that numbered as few as 20 birds in 1994 and is currently considered extinct in the wild. No alala have been seen in the wild since 2002.
The Hawaii Endangered Bird Conservation Program, a field program of San Diego Zoo Global, manages the captive breeding of this endangered species at the Keauhou Bird Conservation Center in Volcano. The state Division of Forestry and Wildlife, the U.S. Fish and Wildlife Service and Kamehameha Schools are also partners in the program, which strives to restore population of critically endangered Hawaiian forest birds, particularly the alala.
A keystone species of the Hawaiian forest, the alala is the only surviving member of a group of crow speicies that once inhabited the Hawaiian archipelago prior to human colonization. These birds were almost eliminated by threats like predation by nonnative mammals and the io (Hawaiian hawk), introduced diseases, habitat loss, fragmentation and inbreeding. The alala has been difficult to propagate in captivity because the hatch rates are impacted by embryonic mortality and congenital abnormalities. To maximize reproductive success, techniques such as artificial incubation and hand rearing are used.
“Our achievement is a great testament to the dedication and expertise of our team in Hawaii and San Diego, as well as the long-term vision and collaboration of our partners,” said Richard Switzer, applied animal ecology associate director at the San Diego Zoo Institute for Conservation Research. “With more than 100 birds now in the captive flock, we are in an even stronger position for the next phase of the species recovery program — re-establishing the species in its place within the Hawaiian forest ecosystem.”
The 100th hatchling was born on May 31. As a last resort, the center has continued with assisted hatching for problematic eggs — those that are long, narrow and almost torpedo-shaped, which makes hatching difficult. In such cases, staff members peel back the eggshell piece by piece and pause to allow for landmarks, such as the retraction of blood vessels and yolk sac. Once a chick is hatched, lights are switched off, and it is left for a few hours to regain its strength, according to the San Diego Zoo website.
“The first week in the life of any alala chick is always precarious,” Switzer said. “Now that this chick is thriving under the care of our hand-rearing team, alongside the seven other chicks hatched so far this season, we are delighted to announce and celebrate the significance of it hatching.”