The Dawson Leuco 



all were savable, and the nest was an elegant and generous structure of 

 compacted mosses, which in itself would have been worthy of preservation. 

 The gloomy chamber in which the nest reposed was not over fourteen 

 inches in total depth from the side wall, and the wonder is that the eggs 

 were not scrambled. 



Of the further descent and of the discovery that the nest on the out- 

 side wall contained young birds a day old, I need not speak. We found 

 the rope was useless, because of the danger of flying rocks. We had to 

 keep close together, so that whatever was dislodged might not acquire a 

 dangerous momentum. We wormed our way up, therefore, as we had 

 wormed down, viz., by bracing our backs against one wall and gluing 

 palms and toes to the other. The round trip consumed exactly two and a 

 half hours. Viewed dispassionately from the outside, the undertaking 

 looks foolhardy enough. I am quite sure I would not go down the same 

 wells to recover a fifty-dollar purse; but I am equally sure that either of us 

 would go as far, or farther, for a set of Leuco's eggs. "94/4-19 Sierra 

 Leuco" now reposes in the cabinets of the Museum of Comparative 

 Oology, and they are not for sale. 



Well ; this is not a monograph of the Leucosticte — nor a biography of 

 the author. What follows must briefly summarize the experience of those 

 glorious days. It is only by spending continuously the months of June and 

 July in Leuco country that one comes to realize how sharply the resident 

 population of Leucos divides upon the question of nesting sites. The 

 cliff-nesters find their favorite sites available in June, and they, accordingly, 

 fall to early in the month. The moraine or rock-slide nesters expect their 

 home sites to be buried in snow until late in June; and, subject to the va- 

 riation of the seasons, nest complements may be expected in such situ- 

 ations at any time from the 1st to the 20th of July. The noisy scenes of 

 courtship, therefore, may extend from the middle of May to the middle of 

 July; but the actual nesting is conducted so quietly, so decorously, that 

 the inexperienced student is likely to be utterly deceived. 



Theoretically, it ought to be very easy to trace a nesting female in 

 such exposed situations as constitute the habitat of the Sierra Leuco. 

 But, practically, one marvels when they do build. At least Leucosticte 

 psychology has not yet been codified. Some females transport materials 

 surreptitiously and spend days at it. Others build furiously while the 

 fever is on, and are done. One bird, which I had traced at midday, had 

 started her nest under a boulder on the side of the central moraine of the 

 Grand Cirque, at a point not three feet distant from the retreating snow- 

 bank, and on a level with it. She secured her material, grass and roots, by 

 the beakful on a young meadow some two hundred feet away; and in the 

 half hour during which I had her under observation she averaged a trip a 



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