LIFE HISTORIES QF NORTH AMERICAN GUIiS AND TERNS. 317 



flying toward the island holding crosswise in its. bill a small fish. The reflec- 

 tions of the bright sun rays from the scales of the fish first attracted my atten- 

 tion. I was next attracted by a series of muffled " yap-yap-ydp's,"" intermingled 

 with several " tear-tear-tear-tear-r-r-r-r-^s " of a very active Forster tern that 

 was pursuing the skimmer and intent upon forcing the big black bird to drop 

 its lawfully acquired prey. The Forster's efforts were without any great suc- 

 cess, however, until the two birds performed the aerial fracas just above 

 my head and about 100 feet in the air. At this Juncture the tern succeeded In 

 scaring the skimmer by a very quick and vigorous dart aimed at the back of the 

 black bird's head, which caused it to drop the; fish, which fell in the mud at the 

 edge of a shallow pond about 75 feet from whe^e I was standing. Recognizing 

 an opportunity to secure positive evidence of the food of the skimmer, I dropped 

 the camera I was carrying and it' was "nip and tuck" between the tern 

 and me who would get the fish. I got the fish, but ,1 have never before received 

 such a scolding, from a bird.^ The Forster tern seemed absolutely beside itself 

 with rage, and followed me for over a mile along the beach, where the captain 

 of our patrol boat was waiting for me with a small motor boat. It was not 

 until we had put off from the island and headed in the direction of our large 

 boat that the tern decided that there was no way of bullying me into return- 

 ing the fish that he felt he had earned by right of combat. I identified the 

 fish, which was about 2i inches long, as a squeteague, or so-called sea trout, and 

 evidently CynoscUm twtjius, the so-called " bastard " weak fish ; and this infor- 

 mation was afterwards concurred in by the United States Bureau of Fisheries. 



Behavior. — In flight the black skimmer is one of the most grace- 

 ful of sea birds and the most highly specialized. Its slender build, 

 its long, powerful wings and its broad forked tail are perfectly 

 adapted to its modes of life. The strongest winds offer but little 

 resistance to the little ball ©^feathers,, supported by two long, siender 

 blades which cut the. air like the keenest razor. It has a strong 

 combination of buoyancy and strength; it is swift and skillful on the 

 wing, and always holds itself in perfect control. When flying in, a 

 flock, as is customary, i|s movements are synchronous to a high de- 

 gree of perfection, the whole flock twisting, turning, wheeling, ris- 

 ing, or falling in perfectunison. 



Of its voice not much can be said in the way of praise* for it is 

 harsh and grating and far from pleasing. When flying out' to meet 

 the intruder on its breeding grounds it indulges in a chorus of pe- 

 culiar nasal barking notes or grunting sounds, like the syllables 

 "Kak, kak, kak," or "Kuk, kuk, kuk," in a low, guttural tone. It 

 also has a variety of soft love notes, sounding like "Kow, kow " or 

 " Keow, keow," suggestive of certain gull notes. 



Winter.— Although gregarious at all seasons the black skimmers 

 are especially so in the fall and winter, when they gather in large 

 flocks flying m close formation, or roosting in dense masses on the 

 sand bars or beaches. It is only when they are feeding that thev 

 are scattered out over the shoals. As soon as the young are able to 

 fly in feeptember the fall migration begins, and they retire from the 

 northern portions of their range to spend the winter about the nu- 



