OF THE UNITED STATES 187 



to devour them. As a group they are cosmopolitan, and in suitable 

 locations on our coasts, and over our great lakes and rivers, they 

 occur in vast numbers. 



As a rule, gulls build their nests upon the ground, and lay from 

 two to three eggs, and these vary much in appearance, but are 

 commonly of a cream color, heavily and variously blotched with 

 dark spots and markings. I have eaten the eggs of numy of the 

 species and always found them excellent. Many of these birds 

 procure their food by plunging in the water for it; others skim 

 over the surface and pick it up; some rob other birds of it; while 

 some may gather shell-fish and other marine invertebrates on the 

 beaches and flats at low water. They are all good flyers, and 

 swim with great buoyancy, ease, and grace. Loud, harsh notes 

 are given vent to by the big species, while the smaller forms have 

 shriller voices, and the young ones have a querulous whine, which 

 is peculiar to them. 



According to a writer at hand, " Several circumstances con- 

 spire to render the study of these birds difficult. With some ex- 

 ceptions, they are almost identical in form; while in size they 

 show an unbroken series, individual variability in size is high; 

 northerly birds are usually appreciably larger than those of the 

 same species hatched further south; the male exceeds the female 

 a little (usually); very old birds are likely to be larger, with 

 especially stouter bill, than young or middle-aged ones. There 

 is, besides, a certain plasticity of organization, or ready suscepti- 

 bility to modifying influences, so marked that the individuals 

 hatched at a particular spot may be appreciably different in some 

 slight points from others reared but a few miles away. Incredible 

 as it may appear, species and even genera have been based upon 

 such shadowy characters. 7 ' Some of the most extensive and 

 highly interesting accounts of our commoner species of gulls are 

 given by A udubon in his great work upon American birds, but to 

 be appreciated these must be read in extenso, and I would be 

 guilty of an injustice to quote any one of them only in part. 



Many of the terns are of small size, and the largest of them 

 rarely equal in this respect the average-sized gulls. With but 

 few exceptions, the tail in them is deeply forked, the wings long 

 and pointed, and the bill slender and acutely sharp, having much 

 the form of the head of a narrow lance. On land they do not 

 walk as well as the gulls, as their feet are more posteriorly 

 placed, while the webbing of the same is not as perfect as a rule. 



