surface just out of sight, the bird, who, meantime, has flushed, settles again after 

 repeated feints. A sort of roof fifteen feet up is formed by wedged rocks, which, 

 in turn, hold much detritus. There is a chance that I may be able to remove 

 this roof piecemeal, but there is a slab of granite poised midway, and inaccessibly, 

 just under the roof, and which, sloping sharply toward the nesting terrace, is 

 likely to shunt material carelessly dropped, in the direction of the eggs. Yet 

 it may be worth a try. 



For an hour I worked laboriously, removing this composite roof, and was 

 rewarded, presently, by the sight of four gleaming white eggs. Further opera- 

 tion, however, confirmed the suspicion that the slanting slab was "doing me dirt". 

 When at last I reached the slab and could remove it, the bird was seen devouring 

 the remains of two broken eggs; while a third egg showed manifest tokens of 

 damage by falling pebbles. Further effort, therefore, was abandoned. 



Set 112/5-22, taken, with nest, July 8th: — A bird was repeatedly flushed 

 from a steep and highly unstable north-facing boulder wall, which forms the 

 crest of the Grand Moraine. I had not attached much importance to these 

 occurrences at first, for the place is near a favorite resting-station and point of 

 departure for Leucos en route to the cliffs; but this morning I approached the 

 place watchfully, and got the exact point of emergence. The nest, which is 

 composed of the drabbest grasses, occupies a niche in sliding detritus, under cover 

 of an angular block of granite, and at a point about a foot and a half in. The 

 female is very solicitous, and has repeatedly passed within a foot of me to cover 

 her eggs, and, even as I write, is pausing momentarily within two feet of my face. 

 If she is disturbed upon the nest, she first withdraws into the deeper interstices 

 of the rocks, leaving the eggs exposed; but when she returns she rushes out and 

 flits around awhile, discontentedly, before trying to brood again. The mate 

 hops about solicitously and chirps as often as the female shows herself; but when 

 she is settled again upon her eggs, he immediately takes himself off and without 

 further ado. Intrusive fragments of rock are such an essential portion of the 

 nest-wall, that several are taken with it, while another sliding fragment, evidently 

 functioning some days since, has dented one of the eggs. 



Set 113/4-22, taken July 8th: On the morning of July 7th, while watching 

 from the lower reaches of the Grand Moraine, I saw, among others, a bird ap- 

 proaching from the north, i. e., the direction of the more exposed feeding levels 

 at a lower elevation, and saw her settle on the middle rocks of the moraine. 

 Believing her to be a female returning from "breakfast", I applied the glasses 

 (ten-power marine binoculars) and succeeded in following her very devious 

 course over an immense distance. The bird, presently, rose and settled on the 

 east end of the summit ridge of the moraine. Then she flew resolutely east 

 across a great snowfield and settled on the black cliffs. Here she made several 

 shifts, and was accosted, finally, by a male, to whom she paid not the slightest 

 attention. Then she fed for a few moments on a sloping snow-field further to 

 southward; then lifted and swung around to westward until she landed at the 

 foot of the main cliffs immediately to the southward of the Grand Moraine and 

 its intervening snowfield. Here she zigzagged across wide areas, alternately 

 perching and rising. A male bird greeted her, as I deemed respectfully and with 

 proprietary interest. Finally, she lighted on a rocky boss about midway of the 

 cliff, at this point about 375 feet high, and about one-third of the way up a deep 

 vertical fissure. Into this well she presently disappeared. This flight occurred 

 at about 10 a. m., and I judged it to be the official return from breakfast. 



In the late afternoon of the same day I was fortunate enough to be station- 

 ed upon the summit of a commanding outlier of rock immediately below this well, 

 when a bird caught my attention as she hopped down from step to step of a 

 single tier, or wedged column of boulders, which occupied a position in the throat 

 of the well, about seventy feet up from the point in the wall, itself 125 feet up, 

 where this well runs out. Arrived at the bottom, the bird launched forth in 

 what I took to be the supper exit, since it occurred at 4:30 p. m. Since the bird 

 was already in motion when I discovered her, I could not tell from what interior 

 depths of the fissure (at this point some forty or fifty feet in horizontal depth) 



20 



