Help Solve the Mystery of Hudsonian Godwit Migration

For the past two years colleagues from the Cornell Laboratory of Ornithology, the U.S. Fish and Wildlife Service, the Chiloe Bird Observatory, the U.S. Geological Survey, and the University of California at Davis have been teaming up to try to answer some of these questions. To do this, we’ve been combining old-fashioned technology with newer cutting-edge technology. Together we’ve placed colored flags on the legs of nearly 600 Hudsonian Godwits.  Twenty-two of those birds are also carrying small, 1.4g machines called "data-loggers" that were created by the British Antarctic Survey, and which track the tagged birds throughout the course of an entire year.

What to Look For

Now that spring migration is upon us and Hudsonian Godwits and other shorebirds that spend the winter in South America are returning to the U.S., we’d like to ask all of you to report to eBird any sightings you might have of these banded Hudsonian Godwits. Birders should be on the lookout for two different groups of banded godwits. Hudsonian Godwits that were banded on Isla Chiloé in southern Chile carry a red leg flag on their upper left leg that carries a combination of either 2 or 3 letters and numbers (see picture above right). On their upper right leg Chilean godwits also have an aluminum US Fish and Wildlife Service (USFWS) band, and a single color band (either yellow, orange, or blue, to denote which year that individual was banded). 

A Hudsonian Godwit banded in Churchill, Manitoba in June 2008 and resighted in central Ohio in October 2008. Notice the white alpha-alpha flag (NN) over a red color band. All Churchill godwits have a white flag. Photograph by Steven Jones.

The other group of banded godwits is from Churchill, Manitoba, on the western shore of Hudson Bay in northern Canada. Researchers there placed white alpha-alpha flags and a red color band on the upper left leg of godwits and a USFWS aluminum band on the upper right leg (see above). As mentioned earlier, 22 of the Churchill godwits are carrying small data-loggers that have been glued to one side of the white flag. 

What We Want to Know

Because the two groups of banded godwits—those from Chile and those from Canada—may be heading toward different places and migrating at different times, we want to know exactly which sites they are using and when they are using them. This type of information will help us to better understand which sites and habitats are most important for different godwit populations, but also how such factors as global climate change and wetland loss may impact godwits during migration.

1. We ask that birders observing Hudsonian Godwits input a number of key pieces of information on their eBird checklists this spring:
2. How many godwits were there? We would like as close to an exact count as possible given the circumstances.
3. Were any of the godwits banded? If so, what color flag were they carrying?  What letters and/or numbers were on that flag? *Use the species comments field for noting this information*
4. Where were they? We would like to know as exact a location as possible. If you were birding a large wildlife refuge, but only saw godwits in one pond, please try to pinpoint that location. How long did they stay? If you saw godwits at a location that you visit often, try to return as often as possible and let us know how long the godwits stayed.
   

Godwit Identification

Identifying Hudsonian Godwits can be tricky, especially if there aren’t other shorebirds around to compare their size with. Most notably, Hudsonian Godwits have brick red barring on their belly and underparts—while this is more pronounced in males than females, females should show some too—and a characteristic long, slightly upturned bill. Another good field mark, especially if you are watching a flock of godwits fly by, is that Hudsonian Godwits have a bright white rump patch contrasting nicely with their brown backs and black tails. Hudsonian Godwits are also noticeably smaller than the Marbled Godwits, while substantially larger than Willets. Be careful when using size though, because female Hudsonian Godwits are also a bit larger than male godwits (which are more brightly colored).

Solving a Mystery

Your sightings of Hudsonian Godwits can help us begin to solve some of the mystery surrounding godwit migration. With resightings of banded birds and an understanding of when and where they stop during spring migration, we can begin to connect those sightings with our data on godwits from both their breeding and wintering grounds. This information will ultimately prove vital not only to understanding godwit migration, but also to the conservation of shorebirds migrating through the prairies every spring. Enter your sightings into eBird today, and help us crack the case!

Contributed by Nathan Senner

Hudsonian Godwit researcher