364 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



later, there is more or less of the drab ju venal down concealed under 

 the feathers, especially around the neck, in birds of the year. 



Adult males are considerably smaller than adult females and much 

 whiter; the sexes can generally be recognized in life, as the females 

 are usually much more heavily barred, except on the face and throat, 

 than males. The darkest males and the lightest females are much 

 alike in color, but the whitest birds, sometimes practically pure white, 

 are always males; and the most heavily barred birds are always females. 

 Adults have one complete annual molt, beginning in July and lasting 

 into the early fall. 



Dr. Nelson (1887) refers to a highly plumaged male as follows: "On 

 one occasion, while traveling south of the Yukon in December, I 

 secured a beautiful specimen of this bird, which was nearly immaculate- 

 milky white, with a rich and extremely beautiful shade of clear lemon- 

 yellow suffusing the entire bird, exactly as the rosy blush clothes the 

 entire plumage of some gulls in spring. The bird was kept until the 

 next morning; an examination then showed that [the] beautiful tinge 

 had vanished and the feathers had become dead white, with barely 

 a trace of the coloring seen the previous evening." 



Food. — Nearly all observers agree that in its Arctic summer home 

 the main food supply of the snowy owl consists of lemmings and other 

 small rodents, when these little animals are abundant; but during the 

 periods of scarcity of lemmings and mice, which happens frequently, 

 the owls must move or find some other food supply; and, during their 

 periodic invasions of more southern regions, they have to subsist on 

 whatever forms of animal life they can find. 



Besides lemmings and various species of mice, these owls have been 

 known to kill and eat hares, rabbits, ground squirrels, rats, moles, 

 and shrews. When hard pressed for food, they will eat whatever dead 

 animals or birds they can find, or will attack animals caught in traps. 



A. L. V. Manniche (1910) writes: 



I often observed owls and hares sitting close to each other showing no sign of 

 hostility. On a certain occasion quite the reverse seemed however to be the case. 



One day in October I had for a while observed a Snowy Owl — an unusally big 

 and dark coloured bird — which had settled on a block of stone on the lowest slope 

 of a large rock. 



After three hours I approached the owl, which at last — as it seemed — very 

 reluctantly left its seat only to settle again soon after on another rock a little 

 higher up the fell. 



I judged from the behaviour of the bird, that something unusual had attracted 

 its attention and went to the spot, where the bird had been sitting, in order to 

 examine the place. 



Two Alpine Hares were sitting in a sort of cavern made by blocks of stones 

 rolled down; they proved very frightened and could hardly be driven off. At 

 last I chased the hares out of their shelter whereupon they sat watching and nerv- 

 ously striking the ground with their hind legs till they soon after with surprising 

 rapidity rushed back to the cavern. It seems evident to me, that the fright of 



