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CIRCULAR 520. U. S. DEPARTMENT OF AGRICULTURE 



culiar and usually harsh notes that in a number of cases have sug- 

 gested local names for the species. When startled, the great blue 

 heron gets under way with raucous croaks and squawks, sounding 

 much like cussing, and in some places it has, therefore, been called 

 "cranky." The green heron under similar circumstances arises with 

 a skeoiv, which earn it such names as "scouck," "scout," and "cow- 

 cow." The night heron often cries quocl\ and so has been termed 

 "quawk," "wop," and "qua-bird." 



GULLS, TERNS, AND SKIMMERS 



Gulls and terns breed chiefly on islands and beaches, but they are 

 free-flying fowl, and from time to time several kinds may be seen 

 in the salt marshes. Some of these birds are rare or difficult to dis- 

 tinguish and are best omitted from an account like the present. The 



Figuee 5. — Herring gull. 



most connnon gull on the Atlantic coast from fall to spring is the 

 herring, or harbor, gull, the connnon sea gull (Larus argentatus) 

 (fig. 5). It is somewhat larger than a crow; the back and most of 

 the wing are pearl gray, the head, underside, and tail white, and the 

 tips of the wing barred black and white. It breeds from Massachu- 

 setts north and west and winters along the whole coast, from which 

 in fact it is entirely absent only a few weeks in summer. 



A similar-appearing but somewhat smaller species, the ring-billed 

 gull (L. delaicarensis), can be surely identified in the field only by 

 a black cross bar near the tip of the bill. 



The laughing gull and Bonaparte's gull are common representa- 

 tives of another group — the black-headed gulls. Adults in breeding- 

 plumage are easily recognized; but in winter the black on the head 

 mostly disappears, and the young do not attain the full breeding 

 plumage until the second spring after the year in which they were 

 hatched. In this group the laughing gull (Z. atricilla) is a little 



