THE BEOAD-TAILBD HUMMINGBIRD. 211 



7,000 feet up to timber line, nesting almost everywhere between these points; 

 and a large pine tree seems to answer equally well for a nesting site as a small 

 bush. In trees the nest is frequently saddled on a large limb, but it is more 

 often placed in low bushes, particularly on willow branches overhanging water. 

 The male has a curious habit of flying up almost perpendicularly, 100 feet or 

 more, in the vicinity of the selected nesting site, and he frequently repeats this 

 performance three or four times in succession before alighting on some dead 

 limb. The female is very loath to leave her eggs, and if driven off will return 

 again directly, even though the intruder's hand is placed within a few inches of 

 the nest." 



As far as my limited observations go, all of our Hummingbirds indulge in 

 this perpendicular flight during the nesting season, and not a few of the nests 

 were found by me while watching these birds go through this performance, 

 which is not alone confined to the male; the female also does it. On the first 

 arrival of this species in the spring it is comparatively common in the lower 

 foothills and valleys, and unquestionably breeds here. By the time the young 

 are large enough to leave the nest the majority of the flowers have ceased 

 blooming, and as the country begins to dry up more and more these Humming- 

 birds retire to higher altitudes in the mountain parks, where everything is now 

 as green and bright looking as it was in the lower valleys two or three months 

 earlier. Here they raise their second broods under nearly similar conditions as 

 the first; the former are by this time well able to take care of themselves and 

 can be seen frolicking about everywhere. These vertical migrations, if they can 

 be called such, frequently account for the entire disappearance of certain species 

 in summer from localities where they may have been exceedingly numerous a 

 couple of months earlier, and the gradual diminution or actual scarcity of the 

 food supply plainly accounts for the sudden change in their habitat. 



Mr. Robert Ridgway writes: "The flight of this Hummingbird is unusually 

 rapid, and that of the male is accompanied by a curious screeching buzz while 

 it is followed through an undulating course. Long before the author of this 

 curious sound was detected its source was a mystery to lis. This shrill, screech- 

 ing note is heard only when the bird is passing rapidly through the air, for 

 when hovering among the flowers its flight is accompanied by only the usual 

 muffled hum common to all the species of the family." 1 



According to Dr. C. Hart Merriam, the Broad-tailed Hummer is very abun- 

 dant in the balsam belt and the upper parts of the pine belt in the San Francisco 

 Mountain region in Arizona. In "North America Fauna," No. 3, 1800 (p. 93), 

 he says: "A nest containing two nearly fledged young was found on the limb of 

 a Douglas fir, about 4 feet from the ground, July 31. The principal food plant 

 of this Hummingbird is the beautiful scarlet trumpet flower of Pentstemon 

 barbatus torreyi. During the latter part of August and early September, after it 

 had ceased flowering, these birds were most often seen in the beds of the large 

 Blue Larkspur (Delphinium scopuloruni). They wake up early in the morning 



■U. S. Geological Explorations of the 40th Parallel, 1877, p. 561. 



