Monday, February 19, 2007

ENV: Puaiohi Release

Birds freed in Kauai forest to fight for species' survival
Puaiohi are among the few natives that adapt to the wild
By Diana Leone, Star-Bulletin

Today or tomorrow, depending on the weather, nine endangered puaiohi birds that were raised in captivity will be set free in Kauai's remote Alakai Wilderness.

As the small gray-brown birds fly off into the rain-soaked ohia forest, they'll be facing the toughest days of their lives.

"Most mortality occurs right after release," said Pauline Roberts, coordinator of the Kauai Forest Bird Recovery Project. Instead of being fed several times a day, the birds will have to forage for themselves.

"The foods are new, the weather harsher. They've never flown such large distances before. They've never seen a rat," one of their most dangerous predators, Roberts said. "It's a steep learning curve."

Yet the petite bird also known as the small Kauai thrush has done well.

It is one of the success stories in progress among the 35 threatened or endangered native Hawaiian bird species. The effort to save the birds includes raising them to add to wild bird populations and improving their habitats by removing predators and alien plants and animals.

There are an estimated 300 to 600 puaiohi on Kauai, the only place they have ever been found.

Since 1999, conservation biologists have released 132 puaiohi birds into the wild, said Alan Lieberman, program director of the San Diego Zoo's Hawaii Endangered Bird Conservation Program. The program receives about $900,000 a year from state and federal agencies to raise five species of Hawaiian endangered birds from eggs for release to the wild.

"We are just part of the army that's trying to make the big difference," Lieberman said of his team of 13 people and its partners: the U.S. Fish & Wildlife Service, state Division of Forestry and Wildlife (part of the Department of Land and Natural Resources), the U.S. Geological Survey's biological branch and private landowners.

"Mother Nature is a wonderful thing," Lieberman said. "A chick raised in a cup with tissue paper" and released into the wild, "within a month picks up the right nesting material, goes to a niche in cliff wall and makes a nest. ... They just know."

Yet all Hawaii's native birds, even those not listed as endangered, face an uphill battle. Of more than 140 native species and subspecies known to have existed before humans came to Hawaii, half are gone. Of the 71 survivors, 15 teeter on the brink of extinction, with 500 or fewer animals in the wild. A number of those birds haven't been sighted in years and could be gone already.
Hawaii's native birds have struggled against increasing odds in the face of alien threats to their island paradise. These include:

» Mosquitos, which can spread malaria and avian pox that have killed many native birds.

» Pigs, sheep and goats, which destroy native plant life.

» Rats, mongoose, cats and dogs, which prey on native birds and their eggs and young.

Lieberman emphasizes that his program "does not put any wild bird population at risk. We've taken eggs, not live birds." All 230 puaiohi raised in captivity are descendants of the original 14 fertile eggs taken from wild birds' nests in 1996-97.

Any captive raised birds that survive add to the wild bird flock. Scientists in the field have observed puaiohi released in prior years raising families of their own, having bred with both wild and fellow captive-bred birds.

Of the five bird species raised in captivity and released to the wild, the palila, nene goose and puaiohi have done well.
The alala (Hawaiian crow) has no wild population, and whether the 52 captive birds can ensure its survival remains uncertain.

A new program to raise Maui parrotbill is too new to assess, but the hope is to establish a second wild group, as was done with the palila on the Big Island.

"It's a great privilege to be here and do conservation work," said Roberts, who spends hours tracking puaiohi in the rainy Alakai wilderness via tiny radio transmitters.

The bird, which is "bigger than a canary but smaller than a zebra dove ... could be sitting in a tree right next to you and you wouldn't see it," Roberts said.
Roberts notes that the kamao, or large Kauai thrush, has not been seen since 1989. Some might still exist. Or not.

"That's what I don't want to happen to the puaiohi," Roberts said. "This is a species that has lasted thousands and thousands of years. It would be so hard to lose them. I don't want to even consider it as possibility."

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