flock-feeding, cormorants exploit school- 

 ing fishes. Active fishing is confined 

 almost exclusively to the front line of 

 birds, and as many as one quarter to one 

 half of the birds may be underwater at one 

 time. 



Peak densities of wintering waterfowl 

 on the Atlantic coast occur in the mid- 

 Atlantic states, but large numbers of 

 several species are found on the New Eng- 

 land coast, some of which use tidal flats. 

 North American migratory waterfowl that 

 pass through or winter along the New Eng- 

 land coast use the Atlantic flyway, which 

 is one of the four great North American 

 migratory flyway systems (Lincoln 1935, 

 cited in Gusey 1977). Unlike the long, 

 nonstop migratory flights of shorebirds, 

 waterfowl often follow the coast, stopping 

 occasionally to rest and feed. Flocks even 

 take up residence in areas for extended 

 periods. For example in Massachusetts, 

 oldsquaw may appear during the middle part 

 of October, remain until the middle of 

 November, and then fly farther south 

 (MacKay 1892). 



Geese (Canada geese and brant) fre- 

 quent the New England coast primarily dur- 

 ing the winter, although a small number of 

 introduced Canada geese breed in New Eng- 

 land as well. As herbivores, Canada geese 

 forage on submerged eel grass ( Zostera 

 marina ) and algae in shallow coastal areas 

 by reaching down into the water with their 

 long necks, often tilting their tails 

 straight up in the air. Brant are true 

 sea geese with well -developed salt glands 

 that enable them to drink salt water. Al- 

 though they are usually herbivorous, brant 

 also eat crustaceans, molluscs, and poly- 

 chaetes (Bent 1937). Before the 1930's, 

 brant fed almost exclusively on eelgrass. 

 After a blight destroyed much of the eel- 

 grass in the northeast, the brant popula- 

 tion declined dramatically. Since then, 

 brant have switched their foraging prefer- 

 ence to Ulva (sea lettuce) and although 

 the population is reduced compared to that 

 in the 1930's, its numbers have increased 

 in recent years. 



The majority of wintering ducks and 

 mergansers in New England belong to only a 

 few species. Diving ducks and mergansers 

 use tidal flats at high tide as one of 

 several habitats for catching small fish 



and invertebrates, while the dabblers are 

 more restricted to shallow coastal areas 

 and may feed extensively on tidal flats at 

 high and low tide. Stott and Olson (1972) 

 found all wintering species in New Hamp- 

 shire (scoters, goldeneye, red-breasted 

 merganser, oldsquaw, and bufflehead) to be 

 within 450m (1,476 ft) of the shoreline. 

 Competition between these wintering birds 

 appears to be reduced as a result of 

 species-specific habitat and food prefer- 

 ences. Many species of sea duck studied 

 were consistent in their habitat usage 

 from arrival in the fall until departure 

 in the spring (Stott and Olson 1973). 

 Within the study area, there were sandy 

 beaches, rocky outcrops, and bays. The 

 scoters preferred to feed in areas adja- 

 cent to the sand beaches, while goldeneyes 

 and red-breasted mergansers most often 

 foraged closer to the rocky headlands. 

 Oldsquaws showed no consistent habitat 

 preferences and buffleheads were almost 

 exclusively restricted to the quieter 

 bays. All these species are divers. 

 Ninety percent of the scoter's diet con- 

 sisted of molluscs of which the Atlantic 

 razor clam ( Ensis di rectus ), Arctic wedge 

 clam ( Mesodesma arctatum ), and blue mussel 

 ( Mytilus edulis ) were the most abundant 

 species. Although the goldeneyes and red- 

 breasted mergansers overlapped in habitat 

 preference, the goldeneyes ate small crus- 

 taceans, with some gastropods and poly- 

 chaetes, while the mergansers were fish 

 eaters, consuming killifish and silver- 

 sides. Small sand shrimp comprised 90% by 

 volume of the buffiehead's prey items. 

 Nilsson (1969) found similar habitat 

 segregation among wintering ducks in 

 southern Sweden, but in his study he found 

 goldeneyes to feed mainly over mud bot- 

 toms. 



Waterfowl are the only group of 

 coastal waterbirds that constitute a com- 

 modity harvested for recreational use. 

 The bulk of each year's harvest in New 

 England is dabbling ducks; the major spe- 

 cies taken are black ducks, mallards, and 

 geese. Eiders and oldsquaw are also taken 

 in numbers along the coast of Maine (W.H. 

 Drury; College of the Atlantic; Bar Har- 

 bor, Maine; April 1981; personal communi- 

 cation). The dabbling ducks are mainly 

 herbivorous but omnivorous in that they 

 eat whatever their feeding techniques 

 catch in shallow submerged vegetation. 



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