18 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



Finally the tern dropped the fish, which one of the jaegers secured 

 in mid-air. Later the two dashed into a flock of about a hundred 

 terns and chased them right and left. The terns screamed and 

 darted around in great confusion; some retaliated by chasing the 

 jaegers. 



Although this bird well justifies its name parasitic^ it occasionally 

 does some foraging for itself; thus King (1836) says that it also 

 "subsists on putrid fish and other animal substances thrown up by 

 the sea." Turner (1886), at St. Michael, Alaska, says it eats "fishes 

 that had been cast on the beach, shell fish, and other animal food. 

 They also eat the berries of Empetrum nigrum.'''' The latter is the 

 crow berry or the curlew berry of the north, the berry on which the 

 curlew formerly fatted in countless numbers. Turner also relates 

 an instance where a parasitic jaeger picked up a freshly torn-off 

 muskrat skin that was floating on the surface of the water. 



It seized the skin in its beak and then passed it to its claws, by which it car- 

 ried it off a little distance and began to strip the adhering muscle and fat 

 from it. 



Nelson (1887) reported that this species eats also shrews, mice, and 

 lemmings. Eifrig (1905) found bones and feathers in the stomachs. 

 Seton (1908) says that in the region of the lakes of the barren 

 grounds " it lives much like a hawk or a raven, coming when a cari- 

 bou is killed to share in the oflal. Once saw one capture a Lapland 

 longspur on the wing, and have often seen it pursuing ground squir- 

 rels." Preble (1908) gives the stomach contents of two taken near the 

 Great Slave Lake; the first contained various insects and the bones 

 of a small bird, evidently a young tern, and the other a dragon fly, 

 various beetles, and a small fish. Anthonj^ (1906) says: 



These deep-sea individuals had their stomachs tilled to overflowing with fish 

 spawn about the size of No. 5 shot, evidently of some species spawning on the 

 surface where the bird could pick it up without trouble. I have seen this jaeger 

 in Bering Straits diving for surf smelt, together Avith Pacific kittiwakes; but, 

 like all of their group, they found it difficult to get below the surface, even with 

 the help of a drop of 6 or 8 feet above the water, and seldom neglected an op- 

 portunity to rob the Arctic tern or kittiwake. 



Behavior. — The flight, swimming, and diving of this species have 

 all been mentioned in the feeding habits. While the first is rapid, 

 graceful, and falcon-like, the two last are seldom indulged in, and not 

 very efficient. It is, indeed, a bird of the air and outside of the 

 breeding grounds is rarely seen on shore. On one occasion, however, 

 at Ipswich, I saw a flock of 10 of these birds on the smooth, hard 

 beach. 



In the chase of terns, it is the tern that uses its vocal powers, and 

 the voice of the jaeger is rarely heard. Nelson (1887) says: 



