great black-backed gulls for successful nesting. For example, most of the 

 larger tern and laughing gull colonies in New England have been taken over by 

 herring and black-backed gulls (Nisbet 1973). In Maine many of the successful 

 tern and alcid colonies are found on islands where lighthouse keepers 

 controlled herring gull numbers (Drury 1973). Young puffins and razorbills 

 are also frequent victims of gull predation. If gull-free islands are 

 required by these species of seabirds, then adequate nesting habitat may be 

 lacking. 



SHOREBIRDS 



Shorebirds are a closely related group of species (order Charadriiformes , 

 suborder Charadrii) that are represented in Maine by sandpipers, plovers, 

 turnstones, godwits, curlews, dowitchers, and phalaropes. Thirty-three 

 species of shorebirds commonly occur along the Maine coast (table 14-2) . 

 Seven additional species visit occasionally in very low numbers. The Maine 

 coast is most important as a feeding and resting area for migrating 

 shorebirds, but six species (piping plover, spotted sandpiper and four upland 

 species) breed along the coast and one species (purple sandpiper) is a winter 

 resident (table 14-10). Of the six breeding species the killdeer, snipe, 

 woodcock, and upland sandpiper are primarily found in upland habitats and are 

 discussed in chapter 16, "Terrestrial Birds." 



Shorebirds are found in most marine, estuarine, and palustrine habitats 

 ranging from deepwater marine to estuarine intertidal emergent wetland 

 (saltmarsh) . Most species have specialized feeding and roosting habitats 

 (tables 14-11 and 14-12 respectively). The most important feeding habitats 

 are estuarine and marine intertidal mudflats, and the most important roosting 

 habitats are sand and gravel beaches or spits, and nearshore ledges. 

 Shorebirds may also roost on salt pannes in estuarine intertidal emergent 

 wetlands, in fields, golf courses, on tops of buildings, or on rocky ledges. 



Shorebirds feed largely on marine and estuarine invertebrates in the 

 intertidal zone and may help supress the abundance of many prey species. They 

 consume a substantial amount of the secondary production of the intertidal 

 system and, because of their transient nature, represent an important energy 

 loss from these systems. Shorebirds, in turn, serve as prey for certain 

 falcons (including the endangered peregrine), accipiters, and marsh hawks. 



Shorebirds are now of little direct economic importance, although in the past 

 they were hunted and sold as food in many urban centers and used in the 

 millinery trade. They have high aesthetic and recreational values (bird 

 watching) . 



Shorebirds should be given special consideration by management authorities 

 because large numbers of these birds depend on coastal habitats for feeding 

 and resting during their long migration from the Arctic breeding grounds to 

 South American wintering areas (Morrison 1977). In addition, they often 

 concentrate in relatively small areas, a practice which can make them 

 susceptible to habitat disturbance and certain environmental contaminants. To 

 date, migratory shorebirds generally have been neglected by decisionmakers who 

 plan coastal developments. They are given only modest consideration in 

 environmental impact statements and in oil-spill cleanup plans. 



14-24 



