Boston Harbor Common Eider Satellite Tracking Study

In 2013, the U.S. Fish and Wildlife Service and research partners initiated a satellite telemetry study focused on mapping the seasonal movements of Common Eiders (Somateria mollissima) breeding among the Boston Harbor outer islands. The telemetry effort is in response to annual die-off events of Common Eiders near the Wellfleet, Massachusetts area. Between 1998 and 2011, eleven recognized mortality events have occurred in the Common Eider population breeding along the coast of Cape Cod, Massachusetts. The numbers of eiders involved in these outbreaks have ranged from 30 to 2,800, with estimated total losses exceeding 6,000 birds. Most of the affected eiders were found dead along shoreline beaches of Cape Cod. Between 2009 and 2011, eider carcasses were collected and examined in the laboratory. In 2010, a novel orthomyxovirus (influenza virus) tentatively named Wellfleet Bay Virus (WFBV), was isolated from a few birds. Currently, Common Eiders are the only species known to become infected with WFBV.

Project Components

In the spring of 2013 and 2014, BRI biologists partnered with the U.S. Fish and Wildlife Service and others to capture Common Eiders at the Boston Harbor outer islands nesting colonies. We used floating mist nets to capture male and female Common Eiders near their nesting colonies. Land-based crews also captured female eiders on their nesting islands. We mist net trapped a total of 64 Common Eiders, of which 31 healthy adult male (15) and female (16) eiders were selected to receive a satellite transmitter.  In addition, all captured eiders were banded, weighed, measured, and had a blood and feather sample collected for WFBV, contaminant, and stable isotope screening and analysis.

The eiders selected for radio attachment were immediately shuttled by boat to a neighboring island containing an enclosed structure suitable for surgeries. Wildlife veterinarians performed the surgeries implanting satellite transmitters in the eiders.

 Project Update

We are currently monitoring the movements of the 31 Common Eiders tagged with satellite transmitters. These eiders, originally tagged and breeding in Boston Harbor, have dispersed to varying molting locations in the U.S. and Canada including: Boston Harbor, coastal Maine, the Bay of Fundy, Anticosti Island, and the Gulf of St. Lawrence Estuary. Approximately 50% of the eiders marked in 2013 wintered in the Boston Harbor area and the remaining 50% in the Nantucket Sound region. An additional 12 transmitters are intended to be deployed in Common Eiders from the Boston Harbor nesting islands in the spring of 2015.

Project Funders/Collaborators

Photo Credits: Floating mist nets being deployed near a Common Eider nesting colony © BRI-Lucas Savoy; A male Common Eider equipped with a satellite transmitter © Josh Beuth