Various techniques used to capture the scoters included mist netting, night-lighting, and net capture guns. All captured ducks were transported to a veterinary hospital where surgery was conducted following general anesthesia procedures. PTT100 transmitters (26 and 39 grams) manufactured by Microwave, Inc., Columbia, Maryland, were implanted into the duck's abdominal (coelemic) cavity with an external (percutaneous) antenna coming from the back of the duck. Eight of the surf scoters from Chesapeake Bay successfully migrated to possible breeding areas in Canada and all 13 of the black scoters migrated to suspected breeding areas. Ten of the 11 black scoter males migrated to James Bay presumably for molting. Updated information from the ARGOS Systems aboard the NOAA satellites on scoter movements was made accessible on the Patuxent Website. Habitat cover types of locations using GIS (Geographical Information Systems) and aerial photographs (in conjunction with remote sensing software) are currently being analyzed to build thematic maps with varying cosmetic layer applications.
Other satellite tracking studies conducted as part of this project include the tracking of long-tailed ducks in Nantucket Sound to learn more about their movements in the Sound in regard to a proposed wind turbine project by Cape Wind Associates, Inc. The seaduck project is also being used for the delineation of the breeding habitats of seaducks in northern Canada and the routes the ducks take between breeding and wintering areas on migration. The Atlantic Seaduck Project has modified the techniques used to instrument seaducks with implantable satellite transmitters, which is improving this technique for other researchers throughout the world. In this regard, we have initiated a telemetry project using dummy transmitters with captive seaducks and lesser scaup. Modifications of the implantation techniques have been used on new projects, especially the large three-year project in Argentina with four species of ducks. We hope that what we learn will be of value to waterfowl researchers in South America and other areas where ducks are being studied with satellite telemetry techniques.
Many factors related to human population increases have been implicated in causing changes in the distribution and abundance of wintering seaducks. Analyses of the gullet (esophagus and proventriculus) and the gizzard of seaducks are currently being conducted to determine if changes from historical data have occurred. Over 1600 waterfowl samples have been analyzed. Scoters in the Bay feed predominantly on the hooked mussel and several species of clams. The long-tailed duck appears to select the gem clam in greater amounts than other seaducks, but exhibits a diverse diet of other mollusks and crustaceans. Seaduck food habits in the Maritimes are decidedly different, where all three species of scoters feed extensively on the blue mussel. Understanding the feeding ecology of seaducks in wintering areas such as the Chesapeake Bay and the Maritimes will provide managers with a better understanding of the changes in the distribution and abundance of these ducks. Future studies will attempt to determine the effects of experimental diets varying in protein and energy levels on the physiology and behavior of captive seaducks. An attempt will be made to determine if seaducks exhibit an endogenous rhythm in regard to body weight and condition during the winter. Foraging energetics in relation to different food sources found in the Chesapeake Bay are measured in two large aquariums (dive tanks) with scoters and long-tailed ducks. The combined studies being conducted in the Atlantic Seaduck Project will greatly aid the conservation effort for seaducks presently being conducted throughout the world.