e360 digest

A Scientist’s Blog from the Arctic:
Unraveling Mysteries of Migration

By Steve Zack, Wildlife Conservation Society

12 Jul 2011

“We have the Japan bird over here, and the China bird is nearby,” Wildlife Conservation Society field assistant Lizzie Goodrick states confidently into the walkie-talkie. She is reporting to our other field assistants monitoring birds near our remote field camp on the Ikpikpuk River on Alaska’s North Slope. The birds in question — small, long-billed shorebirds called dunlin — have indeed been photographed in those countries last winter and have returned to breed again where we captured, banded, and applied geolocators to them, here in our Ikpikpuk site.

Yale Environment 360 Field Notes
Steve Zack of the Wildlife Conservation Society blogs from the Arctic for Yale Environment 360. The first in a series.
The Ikpikpuk camp, located on the far western edge of the Teshekpuk Lake Special Area in the U.S. National Petroleum Reserve — Alaska, is a 1 1/2 -hour flight by bush plane from near the Prudhoe Bay oilfields to the east, and 70 miles from Barrow to the west. We are in the heart of Arctic Alaska’s biggest wetland complex, surrounded by a truly international assemblage of breeding birds. Birds from every continent, and from every ocean, migrate to Arctic Alaska to breed in the brief summer. And with new technologies and international collaborations, we are teasing apart the geographic details of these birds’ remarkable migratory lives.

Geolocators are the newest high-tech toy to track migratory birds. Consisting of a computer chip, a battery, and a light sensor bound together in a very small package, geolocators gather day length and sunrise time information on a daily basis, revealing the location (latitude and longitude) of a migratory bird over the course of a year. Geolocators do not transmit, and must therefore be recovered. Taking advantage of the site-fidelity of breeding birds gives us the opportunity to retrieve the geolocator a year after applying it.

For dunlins, the tiny geolocator is glued to a band around the leg. Last year at Ikpikpuk, we applied several geolocators to breeding dunlins after capturing them with a bow trap sprung over incubating birds on their tundra nests. Because we also adorn these birds with color “flags” (a band with a stiff flange that sticks out from the leg) and because these flags are color-coded to indicate the region where banded (in this case, green for Alaska), bird photographers around the world can see a flagged bird, photograph it, and identify where it nests. The green flag on our dunlin also had alpha-numeric coding indicating the individual identification; thus “EEK” was photographed in Japan and, with the assistance of the U.S. Fish and Wildlife Service, we saw the picture of our bird in its winter home. Incredibly, another photograph of an Ikpikpuk dunlin came to us from China.

View gallery
Dunlin with geolocator

A dunlin, known as ‘EEK,’ with a geolocator on its right leg.
Lizzie and her partner, John Diener, captured EEK for the second time in two years at Ikpikpuk and retrieved the geolocator. I am taking this and another dunlin geolocator back with me to send to our U.S. Fish and Wildlife colleagues. They will download the data from the geolocators as part of a collective, continent-wide effort to determine where key Arctic shorebird species are wintering, and learn of their migratory pathways to and from the Arctic.

That’s not all. We also flagged and color-banded several semipalmated sandpipers at Ikpikpuk to begin to understand adult survivorship patterns, as part of a continent-wide effort in the Arctic. As expected, most of those banded birds returned this summer to Ikpikpuk to breed, affording us the opportunity to monitor who is back, and who is new to our plots. Semipalmated sandpipers winter on shorelines of South America, quite a journey for a bird that weighs less than an ounce.

Finally, I sighted a female bar-tailed godwit with an orange flag, indicating that it had been banded in Australia. Remote is a relative term, I guess: Ikpikpuk is a veritable gathering ground of birds with fancy jewelry — color bands and flags — from all over the globe. I flew from Oregon, and was surrounded by birds that had arrived from Japan, China, South America, and Australia.

And then there was the champion migrator, the Arctic Tern, which defended its nest by swooping down and striking my head when I got too close. These birds make an annual round-trip from the Arctic to the Antarctic, covering more than 40,000 miles.

The stunning yellow-billed loon that was nesting just across the river likely flew in from the Yellow Sea. The lone Smith’s longspur, singing nonstop because it had no partner to court, winters in the American Midwest. The pomerine jaegers stopped to breed at Ikpikpuk this year, as we had abundant brown lemmings; these birds winter in tropical oceans worldwide, stealing food from albatross and petrels. The male pectoral sandpipers, all puffed up with their chesty flight displays, will soon leave the chick-rearing to females and return to their wintering grounds in southern South America. Finally, graceful tundra swans at Ikpikpuk may be among the swans I see in winter by my home in Portland, Oregon. We are migrants all, drawn to Arctic Alaska.

Steve Zack Yale e360 field notes
Steve Zack
Most of our migratory Arctic shorebirds are thought to be declining, some — such as the semipalmated sandpipers — dramatically so. We are only beginning to understand where in their expansive migratory worlds these birds are facing threats, such as deforestation and development, causing their declines. New technologies like geolocators, as well as satellite transmitters for larger birds, are revealing the details of migratory movements of these and other birds for the first time. With that information, we can look at their migratory geographies and learn of the threats and challenges these birds are facing. Their conservation is truly a global challenge.

A few years ago, my WCS colleague, Joe Liebezeit, and I traveled to South Korea to assess whether some Arctic breeders, like dunlin and the bar-tailed godwit, were infected by avian flu amid a huge outbreak of millions of poultry. There we saw, up close, one of the major threats to migratory birds in the Asian flyway: the new Saemangeum Sea Wall, more than 40 miles long, which has closed off the tidal flow to the most important wetland for migratory birds in all of Asia. As we worked with Koreans to gain research permission, I joked that we wanted to work with “our” birds while they were studying “their” birds. They nodded in amusement. If we could recognize that these and other migratory birds are indeed our collective responsibility, perhaps we could help make migration less perilous for birds in our changing world.

More Posts

19 July 2011: Tracking the Impact of Oil Development on Wildlife

26 July 2011: A Place for Wildlife in the National Petroleum Reserve

2 August 2011: As Climate Warms, a Shifting Landscape for Wildlife

Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies


Donate to Yale Environment 360
Yale Environment 360 Newsletter



About e360
Submission Guidelines

E360 en Español

Universia partnership
Yale Environment 360 articles are now available in Spanish and Portuguese on Universia, the online educational network.
Visit the site.


e360 Digest
Video Reports


Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology


Antarctica and the Arctic
Central & South America
Middle East
North America

e360 VIDEO

A look at how acidifying oceans could threaten the Dungeness crab, one of the most valuable fisheries on the U.S. West Coast.
Watch the video.


The latest
from Yale
Environment 360
is now available for mobile devices at e360.yale.edu/mobile.


An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S.
View the photos.

e360 VIDEO

An indigenous tribe’s deadly fight to save its ancestral land in the Amazon rainforest from logging.
Learn more.

e360 VIDEO

Food waste
An e360 video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs.
Watch the video.

e360 VIDEO

Choco rainforest Cacao
Residents of the Chocó Rainforest in Ecuador are choosing to plant cacao over logging in an effort to slow deforestation.
Watch the video.

e360 VIDEO

Tribal people and ranchers join together to stop a project that would haul coal across their Montana land.
Watch the video.