Great Black-backed Gul 1 



In the early 1900' s this gull was a scarce winter resident (Howe and 

 Allen 1901, Knight 1908) but rapidly increased with protection (Kadlec and 

 Drury 1968a) so that it is now a permanent resident, although part of the 

 population migrates south to the imd-Atlantic area (Fig. 16). The later 

 arrival of this gull in the DelMarVa region relative to the more northern 

 areas is an artifact of differences in numbers of observations. The great 

 black-backed gull is the earliest of the gulls and terns to arrive on the 

 breeding ground. 



Herring Gul 1 



This gull has also become reestablished as a permanent resident in the 

 northeast (Fig. 17). Relatively few observations of this species in the 

 DelMarVa region resulted from the recent southern expansion into this area. 

 The herring gull usually nests 1-2 weeks later than the great black-backed 

 gull. 



Laughing Gul 1 



Laughing gulls nest only locally in New England today (Massachusetts and 

 Maine) (Fig. 18). Its nesting chronology overlaps the herring gull, although 

 it begins slightly later. 



Gull-billed Tern 



This southern tern is similar to the common tern with regard to nesting 

 chronology and often nests with it in mixed species colonies (Fig. 19). 



Forster's Tern 



Nesting chronology of this marsh-nesting tern is similar to that of the 

 common tern even though it is more southern in distribution (Fig. 20). 



Common Tern 



In New England this species generally arrives 1-2 weeks after the Arctic 

 tern (Fig. 21). Mid-Atlantic populations are advanced in breeding by about 2 

 weeks. The protracted period of nesting in the DelMarVa region is probably 

 due to renesting attempts after storm washouts. 



Arctic Tern 



Arctic terns are the first of the northern terns (common, Arctic, roseate) 



to return in spring, but egg-laying activity occurs at about the same time as 

 for the other species (Fig. 22). It is also one of the first to depart from 

 breeding sites in late summer. 



Roseate Tern 



Nesting of this species is more extended than for the common or Arctic 

 tern (Nisbet 1973) (Fig. 23). The New York observations are primarily from 

 one major colony (Great Gull Island). 



86 



