Deep in the Alaka’i, Native Birds Slowly Yield Secrets to Scientists
Kaua’i is often touted as the last great hope for some of Hawai’i’s imperiled birds. Its rain forests are relatively healthy and intact, it’s not yet heavily developed and most important, it doesn’t have the mongoose, which preys on eggs and young of forest birds.
Unfortunately, scientists say, the Garden Island is often overlooked when it comes to conservation funds and research. “Of all the islands, Kaua’i is really understudied, especially the birds,” says ornithologist Jeff Foster. “We’re just seeing the tip of the iceberg on Kaua’i.”
This lack of understanding became apparent to Foster and his colleague, Erik Tweed, while spending the past two years in the Alaka’i Wilderness Preserve. The scientists, who work with the Biological Resource Division of the U.S. Geological Survey, had been monitoring the captive-bred Puaiohi (Myadestes palmeri) released in the Alaka’i. But funding was temporarily discontinued. Now Foster and Tweed are back on the Big Island, working with their supervisor, Bethany Woodworth, on a more expansive proposal for studying and supporting the Puaiohi and other native birds in the Alaka’i. “It would be nice to have a solid research station our there to monitor bird populations and keep the threats down,” Tweed says. “If you study a population for two years and leave, you have to start all over again.”
The proposal, which has been submitted to the Hawai’i Forest Bird Recovery Team, is based largely on field work the two men did before they left Kaua’i. After cobbling together finds, they launched a comprehensive bird survey of the Alaka’i, the first time such an extensive project has been undertaken since John Sincock crisscrossed the swamp from 1968 to 1973. “He determined the known populations and range, but due to hurricanes, essentially the structure of the forest vegetation has completely changed,… so none of those numbers are accurate now,” Foster said. “We wanted to do something that would be relevant today.”
They started with the survey transects that the state uses to count birds in the central Alaka’i every five years, then Foster and a crew of state and federal biologists added 26 new transects, each at least one mile long. They wanted to be sure to include the entire known range of the ‘Akikiki, the Kaua’i Creeper (Oreomystis bairdi) reportedly on the decline. When they were done, they had canvassed the entire Koke’e and Alaka’i plateau, which covers roughly 125 square kilometers, or about 30,000 acres stretching from the top of Wai’ale’ale west to Awa’awapuhi valley, south to Olokele Canyon and north to the Pihea vista.
Foster said the survey team – including Tom Telfer Jack Jeffrey, Glenn Klingler, Jim Denny, Thane Pratt, Thomas Kaiakapu, A’ Silva, Corey Adler and Jay Nelson – was blessed with dry weather, which made it easier for them to navigate the swamp. The lack of rain also made it easier to bear bird calls, which can be difficult to hear above the noise of fast-flowing streams. “Heavy rains al50 destroy nests,” Foster says, “so the drought seems to be helping nesting. We’re not sure how the drought will affect nectar and insect populations, but we saw lots of young birds.”
‘Akikiki were rarely among them. “We detected very, very few creepers, startlingly few,” Foster says. While the survey gave them the proof needed to quantify the perceived decline they detected just 19 creepers this spring, compared to 341 in 1981 – it left many questions unanswered.
“We don’t know why the creeper is declining,” Foster said. Still, the hard numbers they compiled may help nudge the ‘Akikiki and perhaps other Kaua’i forest birds onto the Endangered Species List, where they would be eligible for more assistance. The researchers are still working up statistical comparisons to track population counts of various species over the years, but preliminary field observations were encouraging for some birds.
“We found quite a few ‘Amakihi [Hemingnathus kauaiensis] and ‘Apapane [Himatione sanguinea],” Foster said. “The (endemic) ‘Akeke’e, or Kaua’i ‘Akepa [Loxops caeruleirosois], seem to be doing well. We also found a lot more ‘I’iwi [Vesriaria cocdnea] than we expected, but I wouldn’t say it was doing well. It may be on the rebound finally from ‘Iniki.” Hurricane ‘Iniki, which struck the island with fury in September 1992, ravaged Kaua’i forests, including habitat for rare birds.
Tweed said they detected none of Kaua’i’s rarest forest birds, some of which haven’t been sighted in more than a decade. Scientists agree the Kaua’i Akialoa (Hemingnathus procerus), last seen in 1965, is probably extinct and Tweed thinks the ‘O’o (Moho braccarus), last sighted in the 1980s, is likely gone, too. He still holds out hope for the Nukupu’u, ‘O’u and Kama’o (Hemingnathus lucidus, Psittirostra psittacea, and Myadesres myadestinus, respectively) although no sightings have been reported in the past ten years. “I’m not personally ready to write off those birds yet,” he said. “The Puaiohi discovery showed it’s possible to find something.”
The Puaiohi, or small Kaua’i thrush, was thought to be nearly extinct, down to perhaps 25 birds in the wild, when, in 1996, biologist Tom Snetsinger found a colony large enough to support egg collection for the captive propagation program, financed mostly by the state and federal governments and run by the Peregrine Fund. So far, 19 Puaiohi have been released into the Alaka’i. Last year they were breeding successfully with wild birds, bolstering goals of creating a new, self-sustaining colony.
Tweed and Foster are already a little concerned about the recent proliferation of Japanese bush warblers and the effect this might have on natives. Although relative newcomers to Kaua’i, the birds now range from the coast at Hanalei to the summit of Wai’ale’ale. “It’s a species that’s exploded,” Foster said. “You have to wonder, why is it able to fill every available niche? Why is it doing so well when native forest birds aren’t? Will it impact native birds, like the Puaiohi, that share the same diet? Does it have resistance to avian malaria? Since so little work has been done on birds in the Alaka’i, by necessity we have had to do a lot of speculating.”
The Puaiohi monitoring project has already provided some answers. Tweed and Foster were able to show that rats, not cats, were the most common cause of bird mortality – a determination that strongly bolsters the case for predator control. They’re still curious as to how large a toll avian malaria and pox are taking on the Puaiohi and other Kaua’i forest birds. These factors have been identified as major mortality sources of native birds on other Hawaiian islands, and Tweed thinks they’re probably affecting birds in the Alaka’i as well, since the edge of the swamp lies within what scientists call the “mosquito belt” at about 4,000 feet elevation. (Mosquitoes are the vectors that transmit pox and malaria to the birds.) Tweed said he was struck by the contrast between the nearly silent rain forests of the Alaka’i and the raucous morning bird chorus at Hakalau National Wildlife Refuge, which, at 5,200 feet elevation, sits well above the mosquito belt.
Both Tweed and Foster are hopeful that the songs of native birds will continue to be heard in the Alaka’i. They see a research center and ongoing field work as important to achieving that dream. With these, the swamp’s flora and fauna have a better chance of remaining in the public eye and capturing the public support needed for ongoing work and new studies.
“The Alaka’i is a very hard place to work, but its remoteness and ruggedness have helped keep it pristine,” Foster said. “But it is extremely difficult to save an ecosystem when there are so many unknowns. The Alaka’i will always remain a mysterious place, but it is important to conduct research there so we can begin to find some of the answers.
-Joan Conrow
Editor’s Note: The cover article in the most recent (June-July 2000) edition of ‘Elepaio, the publication of the Hawai’i Audubon Society, has a thorough discussion on the difficulties in determining whether a bird is endangered or extinct, with the case in point being the Kaua’i Nukupu’u. See, “Nukupu’u in the Twentieth Century: Endangered Species or Phantom Presence?” by Thane K. Pratt and Robert L. Pyle. Copies of ‘Elepaio may be obtained by calling the Hawai’i Audubon Society office in Honolulu: 8o8 528-1432, or by e-mail at: [email]hiaudsoc@pixi.com[/email]
Volume 11, Number 1 July 2000
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