LIFE HISTORIES OF XORTH AMERICAN GULLS AND TERNS. 277 



The distinguishing features of this plumage usually disappear 

 at a complete prenuptial molt in the spring. At the first postnuptial 

 molt, which occurs in July and August, the young birds become 

 wholly indistinguishable from adults. The winter plumage of the 

 adult is mainly characterized by the brownish black occiput and 

 nape, by the grayish black on the bend of the wing, and by the black 

 bill. The adult nuptial plumage is produced by a complete pre- 

 nuptial molt in the spring. It is characterized by the glossy black 

 pileum, the pure white forehead, the yellow, black-tipped bill, and 

 other minor points in which its differs from the winter plumage. 



Food. — The least tern does not differ materially in its feeding 

 habits from other species of the genus. It obtains its food, which 

 is mainly small fish, by skimming over the surface or by hovering 

 in the air and plunging down into the water after its prey. This 

 plunging habit has given it the name of " little striker." It is very 

 active while feeding and light and graceful in its movements, dart- 

 ing down upon its quarry with speed and accuracy. Its food is 

 generally swallowed on the wing, but if not properlj^ adjusted in 

 the bill it is sometimes dropped and caught again before it reaches 

 the water. Occasionally a bird will alight on the ground to devour 

 its food, and often it flies away with it to feed its mate or its young. 

 Mr. Ora W. Knight (1908) saAv them in southern California "lightly 

 skimming over the surface of the water and feeding on the various 

 small surface-swimming crustaceans and small fish or engaged in 

 feeding on various species of beach insects." The examination of 

 75 stomachs of birds by Warren (1890) killed on the New Jersey 

 coast in sum.mer "showed that they had fed almost exclusively on 

 little fish : not more than four or five had any traces of insects in their 

 stomachs." Audubon (1840) refers to their feeding on "shrimps 

 and prawns." Sand eels are also eaten. 



Behavior. — The flight of this delicate little "sea swallow" is 

 exceedingly light, graceful, and buoyant; it is at times swift and 

 well sustained. Audubon (1840) has well described its movements 

 as follows: 



Wheu you invade their breeding place they will sometimes sweep far away 

 and suddenly return, coming so near as almost to strike you. While traveling 

 their light but firm flight is wonderfully sustained, and on hearing and seeing 

 them on such occasions one is tempted to believe thenr to be the happiest of 

 the happy. They seem as if marshalled and proceeding to a merrymaking, 

 so gaily do they dance along, as if to the music of their own lively cries. Now 

 you see the whole group suddenly check their onward speed, hover over a 

 deep eddy supplied with numberless shrimps, and dash headlong on their 

 prey. Up rises the little thing with the shrimp in its bill, and again down 

 it plunges, and Its movements are so light and graceful that you look on with 

 pleasure and are in no haste to depart. Should this scene be enacted while 



