Tracking a Marathon Migration: Churchill's Whimbrels

March 07, 2013  •  Leave a Comment
 
Flagged Whimbrel, "JM"
 
It’s been a crazy semester this fall, and the Churchill season that I never finished writing about feels incredibly far gone now.  It’s late at night in the middle of a busy week, but physics homework was easier than I thought, so what better time to recall a great summer?
 
After Alaska, I had a few days back in Ann Arbor to regroup and gear up for the 2012 field season.  I was particularly excited, as this was my first season with my own project, studying the migrations of Whimbrels and filming the process (not to mention the 25 beautiful little geolocators that had just shown up in the mail).  After gathering hip waders, knee boots, other boots, clothes for everything from 0-80˚F over the next two months, tripods, camera equipment, and the scattered notes I would need to finish up my last final term paper en route, I was off.
 
A light-level geolocator, weighing just 0.65 grams!
 
After a flight to Winnipeg and a night in a sketchy hotel, I was boarding the train on a rainy morning, headed for Churchill with nearly fifty hours of tracks ahead of me.  The train, ViaRail 693, comprised three passenger cars, a dining car, and a sleeper; all this for about four passengers and as many crew.  I found myself loving the solitude of the train – long hours to sit watching the scenery fly past, to think, to read, and to write the lingering term paper that grabbed at my ankles like a skeleton reaching out of a grave as a frightened protagonist frantically grasps for a tree root.  But I got a good grip on the root, soon freed myself from the zombie paper’s vice grip, and found time to jot down some notes on this new adventure:
 
May 30th --
“It’s wonderfully quiet now, with the whole car practically to myself, and the tracks’ uncertain condition curbing our pace.  The car sways gently, like a big Cadillac on rolling back roads; the soft creaking between cars and the muffled rhythm of the tracks add weight to my eyelids, still reluctantly open as my eyes jerk right to left, following the passing scenery.  Surely I’ve scanned many treetops that have known the touch of a Hawk-owl’s feathered talons, and the blankets of spindly spruces, peppered with creeks, ponds, and boggy clearings certainly suggest that these predators are plenty.  Nevertheless, none revealed itself today as this enticing landscape flew past my panoramic window. It’s nearing midnight, and still a pale blue lingers between the chaotic fingers of silhouetted spruces filing past in the west, and in the east, a gibbous moon is peeking in and out of otherwise invisible clouds.” 
 
The landscape began to take on the familiar (and deeply missed) look of the far north, with dense walls of short, spindly spruces lining the tracks, shading a rich understory of lichens and Labrador tea.  A few shorebirds here and there, as clearings in the forest became more frequent – small groups of what were probably Pectoral Sandpipers, the occasional Lesser Yellowlegs, and as we passed a large open stretch of tundra, a Whimbrel stooped to a landing near the tracks after declaring the bounds of his new territory.  Churchill was close.
 
Hudson Bay, breaking free of ice in early July 
 
I won’t try to describe my fascination with Churchill’s subtle landscape yet again, but it is just as striking every year, and every day (and surely the train’s careful pace only heightened the anticipation).  After settling into the Churchill Northern Studies Centre, I had a chance to wander the study sites on foot, scoping out a few old Whimbrels in the immediate vicinity (I resighted JX about 50 meters from his 2010 nest cup). 
 
This year I was working with Johanna Perz, a masters student at Trent University.  We teamed up in the field to work on some common objectives, but each of us has our own project.  Johanna is focusing on demographics and habitat use: resighting flagged individuals to determine whether Whimbrels’ longevity can make up for the high predation and low nesting success typical here, and whether different habitats have different nest success.  My focus is on migration, so I was eager to find enough nests to deploy all 25 geolocators before season’s end.  These tiny data loggers, attached to the Whimbrel’s legs, record ambient light levels to determine the timing of sunrise and sunset each day of the following year.  From these data, we can calculate the daily latitude and longitude of the individual carrying the logger, and trace their exact routes to the wintering grounds (typically the northern coast of South America).  Identifying the specific stopover sites and wintering grounds these birds use will be a crucial first step towards protecting this species, already seeing significant population declines.
 
Whimbrel at a nest.
 
To my surprise, we deployed our last geolocator on June 26th, and had found 52 nests by the middle of July (far exceeding my optimistic hopes of 30-40).  So for the last few weeks we kept busy with detailed habitat surveys at each of the nests, and trying to film any last footage I would need before heading south. 
 
After the field season in Churchill concluded, I spent August in Ithaca, working on an internship at the Cornell Lab of Ornithology’s Multimedia Department to compile all the footage and produce the short film.  It was an awesome experience to plan, write, design, and edit the project, from start to finish – something I’d only casually experimented with on my own before.  I learned a ton from the Multimedia group, and am very grateful for their help and feedback – the final version can be viewed here: http://andyjohnsonphoto.com/p785051760/h483ce246#h483ce246
 
A Whimbrel takes flight; these wings will carry him more than 10,000 miles in the coming year.
 
And after all this time reviewing the season through video, and now a few stressful months removed from Churchill, I can’t wait to go back next year to retrieve the geolocators and see where “my” birds have gone.  North American Whimbrels’ wintering grounds are well mapped, but perhaps not as precisely as we’ve previously thought.  Some flocks linger along the Atlantic and Gulf coasts of the United States, and many winter in the islands of the Caribbean, or in northern South America; the western breeding group (Alaska & Yukon) winters along much of the Pacific coast, from Oregon to southern Chile.  But recent satellite tracking studies of Whimbrels have shown some birds from the western arctic flying out over the middle of the Atlantic Ocean, en route to Brazil, sometimes flying closer to Africa than the Americas!  With these surprising findings coming out now, it’s especially exciting to speculate about the Churchill birds, which have not yet been specifically tracked to their wintering grounds.  Beyond the universal intrigue of following any individual bird’s international migrations, there is plenty to learn about the specific ranges of these populations (and plenty to look forward to filming in the coming years!).  
 
A male Smith's Longspur, neighbor of the Whimbrels in Churchill.

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