254 NATATORES. 



northern parts of the United States, and in the Polar 

 regions, sit closely on their eggs; while the species 

 that breed in more southern latitudes incubate only 

 during the night or in rainy weather. 



Of the family of Gulls, so well known and so 

 widely diffused, we notice first the species bearing 

 the name of Bonaparte, in allusion to the well-known 

 naturalist. This bird is found at times in great 

 numbers along our sea-board, from the Bay of Fundy, 

 and even higher latitudes, to the coast of Florida. 

 It has also been observed sweeping over the Ohio 

 river, in search of small fishes or floating garbage. 

 When examined after death, the stomachs are found 

 to contain shrimp, young fishes, fatty substances, and 

 sometimes coleopterous insects. In Spring, when 

 the shad enter the bays and rivers to deposit their 

 spawn, this Gull begins to show itself, as if for the 

 purpose of preying upon the shoals, which, however, 

 is not the case. It is described as being very gentle 

 in some localities, scarcely heeding the presence of 

 man. 



The Great Black-backed Gull, the largest of the 

 tribe, delights in sailing over the rugged crags of 

 Labrador. He moves in wide circles, with loud, 

 harsh cries, far above the multitudes of smaller birds 

 below, who instinctively dread the approach of this 

 tyrant, or prepare to defend their young broods from 

 its powerful beak. The fish sink deeper as he ap- 

 proaches, while the other Gulls fly as fast as possible 

 from their enemy. At length he spies, perhaps, the 

 carcass of a whale, and, with fierce cries, darts down 



