Dead eiders found alongshore
Every winter, hundreds of thousands of common eiders, a bird synonymous with the name sea duck, take up seasonal residence on the icy waters surrounding Martha's Vineyard and Nantucket.
In recent months, many have washed up dead along the Vineyard shore. The reasons are still not fully understood but are being investigated by a local ecologist and members of a sea bird program run by the Tufts University School of Veterinary Science.
Rob Culbert of Oak Bluffs, an ecological consultant and local bird expert, said that in the past two months approximately 100 emaciated eiders have washed up along the Vineyard shoreline.
Mr. Culbert was first alerted to the abundance of dead birds by Chas deGeofroy of Chilmark, who found about a dozen birds along a short section of Squibnocket Beach. Not long after that he started hearing about birds found on the north shore.
A drawing of a male and female eider from the classic 1916 edition, "A History of the Gamebirds, Wild-Fowl and Shore Birds of Massachusetts and Adjacent Shores."
Mr. Culbert began working with the Tufts Seabird Ecological Assessment Network (SEANET). With the help of more than a dozen volunteers he collected birds.
Mr. Culbert said that according to SEANET data, approximately 716 dead eiders washed up along 4,000 kilometers of beach over a four-year period compared with 75 to 100 birds found along the Vineyard in just a few months. "That really puts it into perspective," he said.
The current effort is aimed at determining what is normal mortality and what is an unusual event. The intestines and stomachs of the dead birds were filled with a parasite called acanthacephalan.
Mr. Culbert said that given the number of eiders found in local waters it is still not clear if this is a significant problem. "We don't know what the cause is," said Mr. Culbert. "We have not ruled out some disease and want people to know this is happening and that we are looking at the problem, which seems to be food related."
Mr. Culbert can be reached at 508-693-4908 or firstname.lastname@example.org. For more information on SEANET, go to www.tufts.edu/vet/seanet.
According to the book Gamebirds, Wild-Fowl and Shore Birds of Massachusetts and Adjacent Shores by Edward Howe Forbush, issued by the Mass. state board of Agriculture, "while here they usually keep well out to seas. Their food consists largely of mussels, which they can secure in ten fathoms (60 feet) or more of water, and they are so hardy, and so much at home in a storm at sea, that they are rarely seen in Massachusetts, except on salt water."