'Alala recovery left to captive methods
By Timothy Hurley
Advertiser Staff Writer
A draft recovery plan for the endangered 'alala was released yesterday with the aim of increasing the captive Hawaiian crow population from 40 to 77 birds within five years to avoid irreplaceable loss of genetic diversity.
Advertiser library photo • 1987
At the same time, the U.S. Fish and Wildlife Service plan calls for intensive management of the 'alala's forest habitat to improve the survival chances of future releases of the species.
Saving the 'alala depends on increasing the number of birds in captivity from 40 to 77 within 5 years, a recovery plan says.
The revised document was one of two Endangered Species Act-required recovery plans released by the agency yesterday. The other one addresses the endangered Blackburn's sphinx moth, Hawai'i's largest insect, which is found on only three islands: Maui, Kaho'olawe and the Big Island.
The 'alala is one of Hawai'i's rarest forest birds and is found only on the Big Island. But with the last confirmed sighting of the remaining free pair more than 18 months ago, scientists fear that the species no longer exists in the wild.
"Mortality in the wild is likely, under current conditions, to be higher than in captivity. Therefore, captive propagation offers the safest means to safeguard the species' recovery potential in the near term," said Gina Shultz, acting field supervisor for the Fish and Wildlife Service's Pacific Islands Fish and Wildlife Office, in a statement.
Two propagation facilities managed by the Zoological Society of San Diego — the Maui and Keauhou (Big Island) bird conservation centers — maintain the 40 captive adult 'alala.
Within five years, according to mathematical models, the population needs to grow from 40 to 77 birds to avoid further loss of irreplaceable genetic diversity, according to the plan.
"At this time, the most urgent need is to increase the number of birds as quickly as possible ..." Shultz said.
In addition to captive propagation, the plan includes measures to protect habitat where the birds once lived as well as other areas that may be suitable for reintroduction. It calls for restoration of habitat, removal of wild pigs and goats, predator control, and development of strategies to reduce deaths from attacks by 'io (Hawaiian hawk) and of means to combat threats of avian disease.
The draft plan suggests that 'alala be parent-reared if possible and released in areas with adequate vegetation cover to reduce the threat of attack by 'io. Released birds also may receive training to survive in areas with 'io, and other threats — including food sources that attract 'io, such as rodents — will be controlled.
Although 'alala were abundant in the 1890s, their numbers decreased sharply throughout the 20th century despite legal protections. By 1987, the wild 'alala population was reduced to a single bird in North Kona and an unknown number in central Kona, and it was clear that the species was on the brink of extinction.
The draft recovery plans for both the 'alala and the Blackburn's sphinx moth are available for a 60-day public comment period. Copies are available on the U.S. Fish and Wildlife Service's Pacific Islands Web site or by calling the Honolulu office at (808) 792-9400. Written comments may be submitted to the Field Supervisor, Pacific Islands Fish and Wildlife Office, 300 Ala Moana, Room 3-122, Box 50088, Honolulu, HI 96850.
