A four-person Manomet team left this week for Coats Island, a remote sub-Arctic island in Canada’s Hudson Bay, to study troubling developments in Semipalmated Sandpiper populations.
This small, migrant shorebird is one of the most common species in the Arctic and spends its winters in northeast South America.
“There has been about an 80 percent decline in the population of this bird in its core wintering areas according to surveys by the New Jersey Audubon Society, without a correspondent decline, as far as we can tell, in its Arctic populations,” said Stephen Brown, director of Manomet’s Shorebird Science Division. “We don’t know if the species is declining rangewide, or just in some areas, and we need to understand where and why the declines are occurring so that we can work effectively at reversing them.”
The trip’s primary purpose is to discern the reason for this discrepancy. The team will tag the shorebirds over the course of three weeks using geolocating devices.
The tiny geolocators—which weigh only two hundredths of an ounce —are equipped with light sensors that use the time of day to track each bird’s path. Because migrant shorebirds return to the same area of the tundra each summer, researchers next year will attempt to recover the devices so the scientists can identify their wintering areas and migration patterns. There are 37 geolocators allocated for the Coats Island trip and 210 for the whole project.
Coats Island is one of 16 sites in the Arctic Shorebird Demographics Network (ASDN), which brings together scientists across the North American and Russian Arctic to study the declining populations of shorebirds. The network consists of fifteen organizational partners and is co-led by Manomet, the US Fish and Wildlife Service, and Kansas State University.
Eight sites within this network are using the geolocators to track the Sandpipers. This includes a site at the Canning River Delta, on the north coast of Alaska, where fellow Manomet researcher Ian Davies has been camped for the past two weeks and will remain until July 17th.
The Coats Island team will first fly to Ottawa and then Iqaluit, the small capital of Canada’s remote Nunavut territory. After acquiring the last of their supplies, they will take a four-person team the remaining 430 miles to the uninhabited island where they will land on an open stretch of gravel. The team will stay until July 3rd.
The island is the largest uninhabited island in North America south of the Arctic Circle, its native inhabitants having left in the 1970s. Along with the Sandpipers, however, the island hosts a reindeer population, concentrations of walruses on the northern shore, and the occasional polar bear. The team will sleep in a small hut and carefully store their food in order to avoid the bears, which visit the area to look for foods like Sandpiper eggs to tie them over until the ice refreezes and they can go back to hunting seals.
Summer is a misleading term for the Arctic tundra. With constant wind and the possibility of snow any given night, tagging these shorebirds is like “threading a needle outside in the middle of a New England winter,” according to Brown.
The team will also track the nest success of the Sandpiper populations. By collecting demographic information on the shorebirds, the scientists can generate a model for population trends and the long-term growth or decline of the species.
Upon retrieving the geolocators next year, there are two possible outcomes to the scientists’ work. If the birds’ migration paths from all across the arctic converge on their traditional core wintering areas, the decline observed in these areas suggests a serious problem for the species. If, however, some birds winter in areas that were previously not considered part of their wintering habitat then conservation of these new sites will become a priority. The latter result would be a positive sign for the shorebirds’ population but also require new conservation efforts where none now exist.
The groups at Coats Island and the Canning River Delta will be sending back updates of their trips via satellite. You can follow these posts at www.shorebirdscience.org.
– Gordon Bailey