Biologists visit Yukon shorebird in South Pacific

SUZANNE CHUTARO

February 15, 2008 at 10:59AM AKST

For The Tundra Drums

Editor’s note: This story first appeared in the Marshall Islands Journal on Dec. 14.

A team studying the migratory pattern on of the bristle-thighed curlew bird, known in the Marshall Islands as the kowak, arrived in Majuro last week to track down a tagged curlew that had migrated from Alaska to spend its winter at Maloelap Atoll.

The kowak, tagged in June along with 11 other kowaks with a satellite transmitter, has flown about 6,000 miles nonstop from its breeding ground at the Yukon River Delta in Alaska to settle on the island of Nawoj, where she will spend nine months molting and regaining her strength to make her return trip to Alaska in early May.

Wildlife biologist Lee Tibbitts of the U.S. Geological Survey Alaska Science Center and Eric VanderWerf of Pacific Rim Conservation told the Journal that they visited Maloelap in search of their kowak, which they successfully found on Saturday, Dec. 8.

They had actually lost transmission from this particular Maloelap kowak three months ago. But Tibbitts explains that based on the behavior of other tagged kowaks, which are still transmitting their locations via satellite, once they reached the island of their choice, the pattern shows that they remain in the same location throughout their stay in the islands.

According to Tibbitts, 10 of the 11 kowaks they’re monitoring through satellite telemetry arrived in Micronesia in August – seven of which are in various islands in the Marshall Islands. One flew all the way to Kiribati and another to Nauru. One flew only as far as Hawaii and the last stopped transmitting in flight so they’ve lost track of it.

However, of the seven kowaks that are in the Marshall Islands, two are at Likiep, one is at Bikini, one at Rongelap, one at Enewetak, one on Mili and the final one, which was actually tracked down and spotted, is at Maloelap. This particular Maloelap kowak had an additional tag on her which had a data logger tag that provides information on her flight altitude by logging barometric pressure during her flight to the Marshall Islands.

The kowak, Tibbitts said, was chosen because it’s a "species of concern" for U.S. scientists. The South Pacific Regional Environment Program has also identified the kowak as a "globally threatened species in need of regional action."

"The reason for this project is to figure out their migrating patterns, (to answer) why they go to certain locations and what they need" to ensure their survival, Tibbitts said.

In 2006, when the program started, Tibbitts said they studied the population of kowaks from the Seward Peninsula in Alaska, a breeding ground located north of the Yukon River Delta. So far the team has learned that the Seward Peninsula kowaks prefer to spend their winter in French Polynesia, whereas the kowaks from Yukon prefer Micronesia.

"Because these are vulnerable species, we want to know where they are and what are their threats," said Tibbitts, who adds that because these birds molt while they are in the islands, their biggest threats are invasive mammals such as cats, rats, dogs and pigs.

"Curlews (kowaks) are especially vulnerable when they are molting because they become temporarily flightless," she said.

It is estimated that there are fewer than 10,000 curlews left.

Studying the migratory patterns of shorebirds of Alaska is a joint five-year project coordinated by the Alaska Science Center and PRBO Conservation Science, based in California. The project, which gained its funding from the U.S.-based Packard Foundation, has stemmed from conservation concerns coupled with fear over bird flu affecting migratory birds.

The project is studying the migratory patterns of six different species of migratory Alaska shorebirds, Tibbitts said. So far only one bird species, the bar-tailed godwit, has been identified as a potential at-risk bird for catching bird flu because it migrates through Asia.