Recent satellite telemetry data have confirmed that Bar-tailed Godwits migrate non-stop from Alaska to New Zealand. Photo by Ted Swem, May 2005, Aropuk Lake, Yukon Delta National Wildlife Refuge, Alaska.

Female Bar-tailed Godwit on the Alaskan breeding grounds. Photo by Ted Swem, May 2005, Aropuk Lake, Yukon Delta National Wildlife Refuge, Alaska.

The round-trip migration of Bar-tailed Godwit E7, as confirmed with satellite telemetry data. Image courtesy of Robert E. Gill, Jr. and Lee Tibbitts, Alaska Science Center, U.S.G.S.

After leaving Yukon Delta National Wildlife Refuge on August 30, a female Bar-tailed Godwit arrived in northern New Zealand on September 7, completing a non-stop flight of over 7000 miles. She was originally captured in February in New Zealand, where she was implanted with a small satellite transmitter and given a plastic leg flag coded "E7."  Since then, scientists have been able to track E7's migratory progress throughout the year—an 8-day, 6300-mile flight from New Zealand to the Yellow Sea in late March; a 5-day, 4500-mile flight from the Yellow Sea to her Alaska breeding grounds in early May; and, finally, her 8-day, 7,200-mile autumn marathon back to New Zealand.  Her recent return to New Zealand definitively confirmed what USGS shorebird expert Robert Gill and his colleagues have suspected for several years—that this species undertakes the longest single-flight overwater bird migration in the world.  The extraordinary flight of the Bar-tailed Godwit is paralleled by the extraordinary level of international collaboration that made this study such a success.

The recent use of satellite transmitter technology for tracking the migration of large shorebirds breeding in North America has been spearheaded by Gill and Dr. Nils Warnock of Point Reyes Bird Observatory.  Together, they are the principal investigators on a major research project funded in large part by the Packard Foundation.  The study will ultimately follow the migration of 6 species of godwits and curlews between their breeding and non-breeding grounds.  They have invited colleagues from around the world to join them in this ground-breaking research, and the response has been remarkable.  Over 50 individuals from 12 countries have contributed their experience, expertise, and enthusiasm to the project.  The USGS's Lee Tibbitts keeps this ever-growing international audience apprised of the birds' progress as their migration data flow into her Anchorage work station

In Region 7, both Migratory Bird Management (MBM) and Yukon Delta National Wildlife Refuge (YDNWR) cooperated with Gill and Warnock.  Because the godwit is one of the high priority target species for highly pathogenic avian influenza sampling, MBM provided funds for satellite transmitters so that scientists could better understand the timing and duration of the godwits' passage through the Yellow Sea, a critical spring staging area adjacent to an H5N1 "hot zone." 

YDNWR has contributed to the project in a variety of ways over the past few years.  Refuge education specialist (and former wildlife biologist), Brian McCaffery, has collaborated with Gill on godwit studies for the last decade.  In 2005 and 2006, McCaffery headed field crews that searched for godwit nests at the Old Chevak field station.  The refuge then hosted Gill and his USGS colleagues for joint efforts to capture birds and deploy satellite transmitters.  Both the successes and the failures of these early pilot efforts paved the way for the even more successful deployments last winter in New Zealand.  In the fall of 2006, McCaffery led an international team investigating the ecology of the godwits near Cape Avinof on the south coast of the refuge.  Researchers from Australia, Canada, Sweden, and the U.S. focused on how the godwits accumulate fat just prior to departing on their monumental trans-Pacific migration.  While there, the team observed several of the godwits with implanted transmitters, as well as over a hundred godwits individually color-banded in New Zealand by their colleagues, Phil Battley and David Melville. 

This summer, YDNWR assisted with selecting a refuge field site and issuing permits for Gill's USGS crew when they deployed abdominally-implanted transmitters in breeding Bristle-thighed Curlews. Like the godwits, these rare curlews launch out over the Pacific every fall en route to more southerly locales.  Unlike the godwits, which fly to Australia and New Zealand, the curlews wing their way to non-breeding areas among the archipelagoes of the central Pacific.  With the exception of limited data on color-banded birds from Hawaii, however, the exact destinations of the refuge's curlews have never been confirmed previously.

The globe-trotting flights of Bar-tailed Godwit E7 have demonstrated not only the value of international research collaboration, but also the value of an international network of protected sites.  She was originally captured at the Miranda Shorebird Centre in New Zealand, a well-known nature reserve that serves as the focus for much local research on migratory shorebirds.  She then traveled to China, where she visited the Yalu Jiang nature reserve, a protected area formally twinned with Miranda as sister sites within the East Asian/Australasian flyway.  From there she flew to Yukon Delta National Wildlife Refuge, one of just a handful of sites within the Western Hemisphere Shorebird Reserve Network designated as being of hemispheric significance.  As other important coastal wetlands are degraded or destroyed, as recently happened at the Saemangeum estuary in South Korea, these officially protected oases of habitat will become increasingly important for migratory birds as they fly from nation to nation over the course of their annual migrations.

The data gathered to date on both Alaskan species are still preliminary.  Scientists with USGS and PRBO will be more fully analyzing these eye-opening data in the weeks and months to come.  The results to date are amazing, but they represent  just the scientific equivalent of hors d'ouevres.  Once the analyses are complete, the results will undoubtedly reveal a sumptuous repast of marvel and surprise regarding these astounding long-distance migrants.