MOUNTAIN BLUEBIRD 623 



will readily distinguish the Mountain Bluebird. The Mountain Bluebird 

 has a hesitating mode of flight, as with the Western, and the wings appear 

 large and broad in proportion to the size of body. In general behavior the 

 Mountain Bluebird is much like the Western Bluebird. In the matter 

 of forage territory the present species displays greater preference for 

 meadowlands, in large measure avoiding forested areas. 



The numbers of these birds present locally at any season of the year 

 are less than the numbers of the Western Bluebird. On Tuolumne Meadows 

 one or two birds per hour of observation was a maximum. On Mount 

 Hoffmann, June 29, 1915, 4 adults were seen near the top of the peak 

 and a few others lower down, scarcity of available forage grounds and nest 

 sites elsewhere in the vicinity having served, perhaps, to concentrate the 

 birds. In the fall months small flocks are formed, 8 having been noted 

 together on one occasion. These loose companies wander about with seem- 

 ing aimlessness. There is no directness of movement in the fall such as 

 characterizes many migrating birds. 



The Mountain Bluebirds had apparently left the territory east of the 

 Sierras before mid-September of 1915 ; yet they were noted in much 

 higher country on two occasions in the latter part of that same month. 

 On September 26 a flock was observed on the slopes of Warren Peak, and 

 on September 28, 4 were observed in Tioga Pass and a like number on 

 Tuolumne Meadows. Mr. C. W. Michael (MS) reports small numbers 

 in Yosemite Valley on October 30, and November 2, 10, and 13, 1920, the 

 only instances of occurrence we know of there. The species is reported as 

 a transient at Smith Creek, 6 miles east of Coulterville, by Mr. Donald D. 

 McLean, who took a specimen there October 8, 1916. In the winter season 

 Mountain Bluebirds make their appearance in the San Joaquin Valley. 

 Two birds noted along the road below Lagrange on December 16, 1915, 

 constitute our only definite lowland record for the Yosemite section, but 

 there are many reports of the winter occurrence of these birds in numbers 

 on the San Joaquin plains. 



The Mountain Bluebird nests in cavities, making use, for the most part, 

 of deserted woodpecker holes. At Tuolumne Meadows one pair was nesting 

 in such a hole, whose orifice was two inches in diameter, and which was 

 situated 7 feet above the ground in a live lodgepole pine. At the Farring- 

 ton ranch near Williams Butte a Flicker hole in a willow stump was 

 utilized. At Mono Lake Post Office a pair of Mountain Bluebirds had 

 appropriated to their uses a ledge in a woodshed, entrance to which was 

 gained through a hole in the wall. Here at a height of 10 feet from the 

 ground a loosely woven nest had been constructed. This nest was made 

 of shreds of bark many of which showed evidence of having been freshly 

 pulled from the trees for the purpose. There were included also numerous 



