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The Honolulu Advertiser
Posted on: Monday, October 22, 2001

Hawai'i's Environment
Newell's shearwater decline mysterious

By Jan TenBruggencate
Advertiser Staff Writer

Something scary is happening with the population of Newell's shearwaters on Kaua'i.

Or maybe several somethings.

Newell's shearwaters are seabirds that nest in burrows in mountain areas. Kaua'i is the only place where they are found in large numbers. Very small breeding colonies also may exist on Hawai'i, Moloka'i and O'ahu.

Although the population appeared to be recovering throughout the 1980s, it has dropped, apparently from multiple factors.

The black-backed, white-breasted seabirds fledge in the fall each year and head out to sea for as long as two years before returning to land.

Many of the fledglings, on their initial flights from the mountains to the sea, are knocked down when they hit power lines, or fly to exhaustion circling brightly lit stadiums, resorts and roadways. Once downed, they are subject to predation by cats and dogs. Many never take off again since it is difficult for them to get airborne without a steep slope and a brisk wind.

Much of their recovery since the early 1970s is credited to the success of the Save Our Shearwater program. County, state, federal and private organizations and individuals collected fallen shearwaters and took them to release sites.

The community pushed for shields on some lighting fixtures to prevent too much stray light from being directed upward, where it would attract young shearwaters.

A group of researchers led by David G. Ainley studied Kaua'i's shearwaters to determine problems they faced. They published their results in an article, "The Status and Population Trends of the Newell's Shearwater on Kaua'i: Insights from Modeling," in the book, "Evolution, Ecology, Conservation and Management of Hawaiian Birds: A Vanishing Avifauna." The book, edited by Hawaiian bird experts J. Michael Scott, Sheila Conant and Charles van Riper III, was published this year by the Cooper Ornithological Society.

The authors of the paper cite two major problems for the birds: the increasing urbanization of the island, and owl and cat attacks in the nesting colonies.

Veteran shearwater researcher Tom Telfer, a wildlife biologist with the state Division of Forestry and Wildlife, said those are certainly issues, but other things also may be playing a role such as changes in the production of food in large oceanic areas where the birds feed. Shearwaters feed farther from shore than many other seabirds.

"There are multiple factors. Albatrosses are suffering some of the same declines. There's something more going on out there, involving the pelagic food supply and distribution," Telfer said.

Jan TenBruggencate is The Advertiser's Kaua'i bureau chief and its science and environment writer. You can call him at (808) 245-3074 or e-mail jant@honoluluadvertiser.com.