Least Tern 



Least terns arrive later than the other small terns (Fig. 24). Time of 

 egg-laying is quite variable both within and between regions. Its egg-laying 

 can be ^ery protracted because of disturbances and other factors, so often no 

 distinct "peak" is observed. Renesting makes assessment of nesting chronology 

 difficult. Fewer observations in the DelMarVa region result in narrow bars on 

 the Figure. Departure is a few weeks earlier in the northern part of its 

 range. 



Royal Tern 



Royal terns Are one of the earliest terns to arrive, but egg-laying dates 

 vary (Fig. 25). At one colony (Fishermans Island, Virginia) egg-laying occur- 

 red almost a month earlier one year than the previous year (Erwin 1975). 

 Usually, egg-laying peaks at the end of May with hatching occurring 4 weeks 

 later. Renesting may occur in late June or early July, but will not extend as 

 late into the season as with the common or least tern (J. Weske pers. comm. ). 



Sandwich Tern 



This southern crested tern nests within royal tern colonies and its nest- 

 ing chronology is essentially identical with its larger congener (Fig. 26). 



Caspian Tern 



Caspian terns nest throughout the interior lake regions of the U.S.; but 

 along the east coast, it is at its northern limit in Virginia with ^ery few 

 records available (Fig. 27). It usually nests later than its close relative, 

 the royal tern, in coastal areas south of Virginia (J. Weske pers. comm.). 



Black Skimmer 



Only one or two pairs nest in Massachusetts annually so the New England 

 section was excluded (Fig. 28). Skimmers usually nest about 1 week later than 

 their nesting associate, the common tern, in Virginia (Erwin 1977b) and New 

 York (Gochfeld 1977). This species probably has a longer breeding season than 

 any of the gulls or terns in the northeast. Eggs may be laid as late as 

 August in both Virginia (Erwin 1977b) and New York (Gochfeld 1977) if preda- 

 tion or storms destroy earlier clutches. 



Black Guil lemot 



This northern alcid arrives very early, but lays eggs relatively late in 

 the season (Fig. 29). It remains in north Atlantic waters throughout the 

 winter. 



WADING BIRDS 



Great Blue Heron 



This species is the earliest to begin nesting, as early as February in 

 Virginia (M. Byrd pers. comm.) (Fig. 30). It frequently winters as far north 

 as southern New England. 



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