As the short Arctic summer draws to a close and Manomet’s researchers finish their expeditions, the team at the Canning River Delta on the north slope of Alaska has made a rare find – a Semipalmated Sandpiper that was previously banded by New Jersey Audubon in Brazil.
Considering that just over a thousand of these tiny shorebirds are banded in Brazil each year out of a total global population of 2.25 million, the probability of the Canning team seeing one are about one in 1,800, according to researcher Ian Davies.
“The odds are definitely stacked against us, but apparently not too severely to stop us from seeing one,” he wrote in a recent blog post.
Even more extraordinarily, however, the Manomet team found a different Brazilian-banded Semipalmated Sandpiper last summer. That bird, a male labeled KKL, was unable to find a mate and was not seen again this summer. This year’s find, a female carrying the band AHU, had a nest and three eggs, two of which appeared ready to hatch.
This phenomenon raises interesting questions for the Manomet researchers who study the birds. Sighting two Brazilian-banded birds suggests a common migratory pattern rather than an unlikely coincidence, according to Davies. The researchers’ use of geolocators to track the birds will help solve this puzzle.
These devices are light enough to not encumber the shorebirds and will provide a record of each bird’s migration if they can be recovered next summer. Manomet’s other Arctic team, which was camped on Coats Island in Hudson Bay, returned last week after placing all of their 35 geolocating devices on Semipalmated Sandpipers. The Canning team placed 29 of their 30 geolocators.
“Success with the geolocators can vary greatly, so this summer seems to have gone extremely well,” said Stephen Brown, director of Manomet’s Shorebird Science Division and leader of the Coats Island team.
Canning and Coats Island are two of the six camps working on the geolocator tagging in the Arctic. New Jersey Audubon has placed geolocators on wintering birds in Brazil. Recovering these devices will help the scientists better understand where the shorebirds migrate to in the winter and whether their population is in trouble.
“Just recovering a few geolocators will provide a wealth of information that no one has had before,” said Brown. “But more than that it will help us with the real goal, which is to fully understand the population trends and wintering habits of this species so that we can better conserve it.”
Both camps are part of the Arctic Shorebird Demographics Network (ASDN), an international collaboration to determine the causes behind declining populations of shorebirds. The project is led by Manomet, the U.S. Fish and Wildlife Service and Kansas State University.
The Canning River team will remain in the field until July 17th. You can follow their updates and photos, sent using satellite link, at the dedicated blog www.shorebirdscience.org. The Boston Globe is also posting the trip reports at http://www.boston.com/lifestyle/green/greenblog.
– Gordon Bailey