LIHU‘E — Huge human steps are traveling a long distance to preserve from extinction a small, native Kaua‘i bird. A dozen more captive-raised puaiohi (Myadestes palmeri), also known as the small Kaua‘i thrush or Palmer’s thrush, were released into the
LIHU‘E — Huge human steps are traveling a long distance to preserve from extinction a small, native Kaua‘i bird.
A dozen more captive-raised puaiohi (Myadestes palmeri), also known as the small Kaua‘i thrush or Palmer’s thrush, were released into the Alaka‘i Wilderness Area last week. The endemic and endangered species is known to live only in the Alaka‘i Swamp area of Kaua‘i above elevations of 3,500 feet.
Adult birds are seven inches in length, dark brown on top, gray on the bottom, with pinkish legs. They have short tails and slender and dark bills, feed on fruit and insects, and prefer the dense understory of gulches. Their sound is like water gurgling.
Last week’s release marked the 10th year of a multi-agency effort designed to reverse the trend that had seen the puaiohi go from slightly uncommon to rare to nearly extinct, said Alan Lieberman, director of field programs for the San Diego Zoo’s Institute for Conservation Research.
San Diego Zoo, U.S. Fish and Wildlife Service, state Department of Land and Natural Resources Division of Forestry and Wildlife, and U.S. Geological Survey Biological Resources Division combined forces for the effort, with assistance from Hawaiian Airlines (transporting the birds from aviaries on Maui and the Big Island to Kaua‘i), Lieberman said.
A full 100 percent of the birds released last year survived, and the biggest stress on the birds once released from captivity is finding their own food, he said.
The birds, raised on the Big Island and Maui from eggs taken from Alaka‘i nests, are brought to aviaries on Kaua‘i to be fattened up and acclimated before release, he said.
The 12 released last week have radio transmitters for tracking purposes with batteries designed to last around 30 days, with the transmitters designed to fall off the birds before their first breeding cycle, he said.
While their numbers are increasing, what is not known is why they became nearly extinct in the first place, Lieberman said. Hurricanes wiped out the other Kaua‘i thrush.
Puaiohi are threatened by rats — which eat eggs, females and young birds right out of the nests — and by habitat degradation caused by goats, pigs and deer, Lieberman said.
Owls are another predator, and mosquitoes carrying avian malaria and avian pox have also killed puaiohi, he said.
Asked why it is important to continue the expensive work of trying to save a single small bird species, Lieberman said, “It’s a valuable piece of Hawaiian heritage, and an integral part of the Alaka‘i, which has lost many species already.”
The puaiohi is also “one of the few species that we can do something about. If we can prevent extinction, we must do everything possible to do so,” he said. “It’s our obligation. They are an important piece of the forest,” and it appears they’re making a comeback.
The released birds breed and reproduce, many within the first year of their release, he said.
Overall management of the park, reserve and forest itself, weed- and pig-control efforts (fencing, etc.), and encouraging the birds to nest in rat-proof structures, will all help with the continued puaiohi population increase, he said.
With last week’s release, there have been 188 captive-bred puaiohi released into the wild. Many have survived and have bred in the wild, Lieberman said.
“The release of captive birds is one strategy to ensure that the puaiohi does not go extinct, however, it cannot be the only strategy,” said David Leonard, DLNR DOFAW biologist.
“Unfortunately, controlling alien plants and non-native predators is very difficult and expensive, however, we are exploring alternatives. For example, we are determining if puaiohi will use rat-proof structures for nesting,” Leonard said in a press release from the San Diego Zoo.
Before the release of these 12 birds, staff worked to reduce the rat population near the release site.
In 1994, it was estimated that 200 puaiohi survived in the wild. The extremely low numbers of puaiohi prompted a collaboration of researchers and scientists from the San Diego Zoo and federal and state agencies.
To help the species recover, in 1996 eggs were first taken from the Alaka‘i to the San Diego Zoo’s Keauhou Bird Conservation Center on the Big Island, where they could be raised in a protected environment.
“While we’re celebrating our 10th anniversary of rearing and releasing the endangered puaiohi, we know there is still a long way to go before this species can be declared recovered,” said Lieberman. “We are proud of our 17 years of restoring the population of Hawaiian forest birds and are committed to the ongoing stewardship of the puaiohi’s forest habitat.”
Using state and federal funds, DOFAW established the Kaua‘i Endangered Forest Bird Recovery Project. This team of biologists collects information on the puaiohi that informs management actions, assists in the release of captive birds, and tracks newly released birds to document their movement and survival.
Because the puaiohi is federally listed as an endangered species, the U.S. Fish and Wildlife Service provides financial support and scientific collaboration to the state to support the recovery effort.
“We congratulate our partners for reaching this 10-year milestone in successfully reintroducing endangered puaiohi into the wild,” said Loyal Mehrhoff, field supervisor for the U.S. Fish and Wildlife Service’s Pacific Islands Fish and Wildlife Office. “Captive propagation is labor-intensive and expensive, but well worth the effort when it contributes toward the recovery of a species.”
At least 21 species of Hawai‘i’s endemic forest birds have become extinct, another 26 species are facing extinction, and most, including the puaiohi, are dependent on intensive conservation measures.
The San Diego Zoo’s Hawai‘i Endangered Bird Conservation Program manages the Keauhou and Maui bird conservation centers, which work with avian species that are dependent on captive propagation for recovery and survival.
The San Diego Zoo’s Institute for Conservation Research is dedicated to generating, sharing and applying scientific knowledge vital to the conservation of animals, plants and habitats worldwide.
