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Fight for survival


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POSTED: Saturday, April 18, 2009

The U.S. Fish and Wildlife Service released a revised recovery plan yesterday for the endangered Hawaiian crow, one of the rarest forest birds in the world.

The new plan hopes to prevent extinction of the bird, known as the alala, and to restore populations to allow removal of the species from the endangered list.

It includes expanding captive propagation, establishing new populations in managed habitat, protecting suitable habitat, managing threats to the species, increasing public support and continuing research and adaptive management practices.

The Fish and Wildlife Service estimates the plan will cost more than $14 million over the next five years, mostly because of the high cost of broad habitat restoration needs.

The birds, which have only been found on the Big Island, have not been seen in the wild since 2002.

“;The fact that the species is extinct in the wild means that its former habitat is no longer able to support the population for whatever reason,”; said biologist Jeff Burgett, who is charged with the recovery for the Fish and Wildlife Service. “;Unless we change it in ways that are better for the bird, it has no suitable habitat.”;

Their habitat has been affected by the introduction of non-native predators and threats such as feral cats, pigs, mongoose and cattle, which can destroy the vegetation of the forest and spread disease.

“;We've let mongoose and cats and rats and all these things out there. They're taking Hawaii away from us, slowly but surely,”; Burgett said. “;If you want to keep Hawaii, then you've got to do something to control those things.”;

Fifty-six alala are now being cared for at two bird conservation centers on Maui and the Big Island that are managed by the Zoological Society of San Diego.

According to population genetic modeling, the population needs to grow to at least 75 to avoid further loss of genetic diversity and to begin reintroduction to the wild.

“;The point is not to keep them in a box,”; Burgett said. “;The point is to build the flock up to the point where they're generating enough young that you can put them back out in the wild.”;

Revered by native Hawaiians, the alala is the second-largest forest bird in Hawaii after the endangered io, or Hawaiian hawk, and is the only surviving member of a group of crow species that once inhabited the Hawaiian archipelago before human colonization.

The population was abundant in the 1890s but declined sharply despite legal protections dating back to the Territory of Hawaii in 1931. By 1987 the alala was reduced to a single bird in North Kona and fewer than 20 in Central Kona.

More than two dozen alala that were raised in captivity were released between 1993 and 1998. However, 21 died, and the remaining six were recaptured and placed with the captive flock. Some that died were found to have toxoplamosis, a disease spread by feral cats.

Inbreeding might also be reducing the reproductive success of the captive population. And loss of wild behaviors in captivity could reduce the survival skills of reintroduced birds, the service said.