LIFE HISTORIES OF NORTH AMERICAN GULLS AND TERNS. 25 



Food. — In their summer homes on the tundra these jaegers live on 

 a varied bill of fare. They are said to feed largely on lemmings, 

 field mice (Microtus), and other small mammals. They catch flies, 

 butterflies, .and other insects and eat their larvae. In the summer 

 they rob bird's nests to devour the eggs and young, and sometimes 

 they pursue and kill wounded birds for food. Probably a few fish 

 are caught and many are stolen from gulls and terns. They also 

 pick up considerable offal of various kinds, as well as small crus- 

 taceans and worms. During the latter part of the season they feed 

 largely on crow-berries (Empetrum nigrum) and other berries. 

 While migrating or during the winter they associate with the smaller 

 gulls and terns, depending largely for food on what they can steal 

 from these industrious birds or what they can pick up, in com- 

 pany with these common scavengers, in the way of garbage. 



Behavior.— -To watch the long-tailed jaeger in flight is one of the 

 delights of the Arctic summer, for it is one of the swiftest and most 

 graceful of birds on the wing ; its light and slender form is propelled 

 by its long, pointed wings with the speed of an arrow, its broad 

 tail serving as an effective rudder, as it twists and turns in pursuit 

 of its fellows or some luckless gull or tern, with its long central tail 

 feathers streaming in the wind. Doctor Nelson (1887) says: 



They appear to be much more playful than the other jaegers, and parties of 

 six or eight may be seen pursuing one another back and forth over the marsh. 

 The long, slender tail feathers and extreme grace on the wing of these birds 

 render them very much like the swallow-tailed kite. 



Mr. Turner (1886) observes that it is " extremely swift on the wing, 

 and when pursuing another bird thrashes the air with wing and 

 tail, giving an undulatory motion to the body." It swims lightly and 

 gracefully on the water, holding its long tail pointed upward ; but I 

 bave never known it to dive below the surface. 



Doctor Nelson (1887) describes the notes as follows: 



They have a shrill pheu-pheu-pheu-pheo, uttered while they are flying, and 

 when the birds are quarreling or pursuing one another the ordinary note is 

 often followed by a harsh qua. At other times they have a rattling kr-r-r-r, 

 kr-r-r-r, kr-r-r-r, kri, kri-kri-kri, the latter syllables shrill and querulous and 

 sometimes followed by the long drawn phefi-pheu-pheu in the same tone. 



All writers refer to the predaceous habits of the jaegers. Their be- 

 havior toward other species is certainly not above criticism. On 

 their breeding grounds they have the reputation of being nest robbers, 

 according to the reports of the natives, eating the eggs and small 

 young of any of the birds which are smaller or weaker than them- 

 selves. Such pilfering is done on the sly, however, for the jaeger 

 is far from courageous and is often attacked and driven away from 

 the nests of gulls, terns, curlew, sandpipers, and other shore birds. 



