It was 13 years ago that the U.S. Forest Service formally recommended establishing a second population of the critically endangered kiwikiu, or Maui parrotbill, to significantly lower its risk of extinction.
When the project finally came to fruition three months ago, after years of painstaking work preparing habitat in the Nakula Forest Reserve, it was hailed as the start of a new beginning for the small olive-green-and-yellow forest bird with fewer than 300 individuals left.
But then something went horribly wrong.
Mosquito-borne avian malaria wiped out 10 of the 13 birds set to be released, including one that died at the release site even before it was set free. The final three are missing and presumed dead.
In the wake of the disastrous reintroduction, scientists are now racing against the clock to keep the Hawaiian honeycreeper — found nowhere else in the world except Maui — from going extinct.
“We have only a small window to do anything,” said Hanna Mounce, coordinator of the Maui Forest Bird Recovery Project.
Although a final decision is expected to come at a meeting Thursday, it appears the program is moving to establish a new vigorous captive-breeding program at a facility on the mainland.
Mounce said she’s hoping the new program will buy time for the Maui parrotbill while scientists come up with new ways to deal with the growing number of mosquitoes moving higher in elevation in isle forests as Hawaii’s climate grows warmer.
Like most Hawaii forest birds, the kiwikiu, with its curved, parrotlike bill, has suffered over the last century from habitat loss, invasive species, disease and predators.
Once found throughout low and highland forests of Maui and Molokai, the species has been relegated to the higher elevations of windward Haleakala. The bird’s range continues to shrink as climate change accelerates and mosquitoes carrying deadly avian malaria move ever higher up the mountain.
As officials with the Maui Forest Bird Recovery Project planned the reintroduction on the leeward side of Haleakala, they were expecting challenges with food availability and predators. They didn’t think malaria would be the top threat, considering the high elevation and the fact that previous surveys found few mosquitoes in the area.
Following the setback, the Maui Forest Bird Recovery Project conducted a mosquito abundance survey of the release area to figure out just how dire the situation is.
The survey found a huge increase in mosquitoes — more than 7.6 times the previous survey.
“The numbers were staggering,” Mounce said.
Now the project team is conducting mosquito abundance surveys on the windward side of Haleakala to see whether the mosquito problem is also as bad in their current range.
“There’s a perception that the birds are safe on the windward side of Haleakala, but they’re not,” she said.
The future had looked promising for a species that became the target of a multiagency recovery effort. The plan to establish an “insurance” population of Maui parrotbills called for bringing together both wild birds from the windward slopes of Haleakala with captive birds from two Hawaii bird-rearing facilities for reintroduction into the Nakula Forest Reserve.
Over the past decade more than 250,000 native trees, many of them koa, were planted in the forest reserve and neighboring Kahikinui Forest Reserve to repair decades of habitat destruction from the grazing of goats, cows and sheep. One of the primary goals was to re-create a largely native forest and understory to act as a home for the new kiwikiu subpopulation.
The failed release left the conservation community reeling.
“It was a punch in the gut,” said Lucas Fortini, research ecologist with the U.S. Geological Survey in Honolulu. “The people over there were pouring their heart and soul into trying to make the release site viable habitat.”
In a 2015 study, Fortini examined 20 native bird species living in higher-elevation forests and found that all of them could lose more than 50% of their habitat in the coming decades due to climate change.
Fortini’s models found that moderate warming would cause the kiwikiu to lose up to 90% of its historic range by 2100, making it one of Hawaii’s most vulnerable species.
As for what happened in October’s release, Fortini said it could have been just a matter of bad timing. Last summer was especially warm — 2 degrees warmer on Oahu and probably elsewhere in the islands. So it could have made conditions especially inviting to the disease-carrying mosquitoes.
Some years will be worse than others, he said, but the truth is that the kiwikiu probably faces extinction without some kind of helping hand from conservationists.
Mounce urged state and federal officials to accelerate their efforts in developing one or more promising new methods for controlling mosquitoes.
She said she’s hoping the situation will improve with the help of technological breakthroughs in three to five years.
“But the timeline keeps getting pushed back,” she said.
Mounce said a nonprofit bird facility on the mainland has expressed interest in giving new vitality to the kiwikiu captive-breeding program, and a decision to move forward on that effort could come during Thursday’s meeting of project partners.
One of those partners, the U.S. Fish and Wildlife Service, didn’t respond directly to a question asking about sending Maui parrotbills to the mainland for captive breeding.
“While the next steps for kiwikiu are currently under discussion between the U.S. Fish and Wildlife Service and our partners, we are committed to the future of the kiwikiu on Maui,” said Michelle Bogardus, Maui Nui & Hawaii Island Team Manager, in an email.
San Diego Zoo Global currently breeds the kiwikiu at the Maui Bird Conservation Center in Olinda and Keahou Bird Conservation Center on Hawaii island, the same facilities where the alala, nene and a variety of other threatened native Hawaiian birds are successfully reared.
Despite a program that started more than two decades ago, however, fewer than eight captive kiwikiu were available for release at Nakula, a fact that required the capture of wild birds for use in the reintroduction effort.
According to the San Diego Zoo Global website, the kiwikiu is a challenging species to breed due to its low reproductive output of one egg per clutch. Additionally, the monogamous species requires pair bonding and has a relatively long period of juvenile dependency.
If a mainland effort gets the green light, at least one important question remains: When is the best time to capture the founding members of the new breeding program?
For October’s release, the birds were rounded up with fine mesh nets in the fall to avoid any conflict with removing adults with dependent offspring. But, depending on the results of mosquito surveys and revised population estimates, Mounce said a decision might have to be made to commence bird capturing immediately.
“Doing nothing is not a choice. We’re not going to do that,” Mounce said.
Maui's honeycreepers by Honolulu Star-Advertiser on Scribd
