442 



NA TURAL HIS TOR Y. 



yet they exhibit peculiarities of their own. They are almost constantly 

 on the wing, turning -so gracefully, and flying so easily, that one cannot 

 restrain his expressions of delight and admiration as he watches them. 

 Now one is sailing slowly and elegantly through the air, when he espies a 

 school of fishes in the water below. Instantly all is changed. The circling 

 flight is stopped, and like an arrow the bird plunges downward to, and 

 even beneath, the waves, and when he mounts upwards again, giving a 

 flirt, to shake off the water, he almost always has a fish. 



Fig. 373. — Ross's gull (Rhodostethia rosea). 



There are numbers of terns belonging to the American fauna ; some 

 large, some small, but all loud-voiced, and all curious. Some maybe found 

 near the sandbars of our southern rivers, while others occur in the valley 

 of the Mississippi, and still others range north into the Arctic seas. Our 

 largest species, the Caspian tern, is shown in the cut, and in a general way 

 represents the appearance of all the group. 



The terns of the Arctic seas have their enemies in the jaegers, sea- 

 hawks, or, as the sailors call them, the ' teasers.' These are large birds. 

 and of one of them Macgillivray, an English naturalist, wrote, many years 

 ago, a mosl interesting account. "The sea-birds are on the wing, wheeling 

 and hovering all around, vociferous in their enjoyment, their screams min- 

 gling into one harsh noise, not less pleasing, for a time, than the song of 



