Shorebirds, such as this semi pal mated 

 England tidal flats in spring and fall, 

 to provide the necessary fat reserves 

 to wintering areas in South America. 

 Wildl ife Service. ) 



sandpiper, concentrate in large numbers on New 

 They consume great quantities of invertebrates 



for long migrations from Arctic nesting grounds 

 (Photo by J.M. Greeny; courtesy U.S. Fish and 



Since shorebird predation nay be 

 intense and focused in areas where prey 

 species are most abundant, these birds 

 probably play an important, if temporary, 

 role in structuring the invertebrate com- 

 munities of tidal flat environments. On 

 Long Island, New York, Schneider (1978) 

 found that such predation resulted in 

 wider spatial distributions of prey spe- 

 cies. By concentrating their foraging on 

 the most abundant prey, shorebirds prevent 

 single species of invertebrates from domi- 

 nating areas of the tidal flats at the 

 expense of others. 



5.3 GULLS AND TERNS 



Eight species of gulls and six spe- 

 cies of terns (family Laridae) occur com- 

 monly in New England. Seven of the four- 

 teen species nest in colonies on the New 

 England coast, and two species, the her- 

 ring and great black-backed gulls, appear 

 year-round. The distribution of nesting 



pairs of colonial wstprhirHt: fhri — ' — ^ 



New England is 



waterbirds throughout 

 given in Table 6. 



Gulls will drop to the surface from 

 flight (plunge diving, Ashmole 1971) when 



54 



