282 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



the vegetable portion of the food of the mountain bluebird consists 

 principally of small fruit. The currants and grapes found were in all 

 probability domestic varieties, but as the grapes were from stomachs 

 taken in December and January, and the currants from one taken in 

 April, they can have but little economic significance." Other items 

 listed are elderberries, sumac seeds, and unknown seeds. In their 

 winter haunts these bluebirds feed largely on mistletoe and hackberry 

 seeds, on the drupes of the Virginia-creeper and on cedar berries, as 

 well as other wild fruits. 



Dr. George F. Knowlton tells me that out of 172 stomachs of this 

 bird collected in Utah 47 contained adults and 4 held nymphs of the 

 beet leafhopper, Eutettix tenellus, a destructive pest. 



Grinnell and Storer (1924) describe its feeding habits very well, as 

 follows: 



In the nesting season and indeed through most of the 3 7 ear the Mountain 

 Bluebird subsists upon insects. These are captured in two totally different ways, 

 according to the habits of the insects sought. For beetles and others which fly 

 through the air a bluebird will take position on a boulder in a meadow or on the 

 low outswaying branch of some tree and dart after the insects which pass by. 

 For insects which live on the ground, such as grasshoppers, the bird mounts 10 

 to 20 feet into the air over the grassland and then by fluttering its wings rapidly, 

 hovers in one place for several seconds and intently scans the surface below, 

 like a Sparrow Hawk when similarly engaged. If something is sighted the bird 

 drops quickly to the ground and seizes it; otherwise the bluebird moves a short 

 distance to a new location which is given similar scrutiny. It thus examines the 

 ground in a manner recalling that employed by the robin though from an aerial 

 location where its scope of view is much greater though less thorough. 



This hovering habit has been noted by numerous observers and 

 seems to be characteristic of the species; it seems to prefer this method 

 of foraging to using posts and wires as lookout points, from which to 

 dart down onto its prey, as the other bluebirds generally do. 



Behavior. — The mountain bluebird is not a swift flier, probably not 

 making more than 17 or 18 miles per hour on its ordinary short flights. 

 John G. Tyler (1913) says that "a company of these bluebirds in 

 flight may be identified at a distance by their peculiar manner of 

 poising for a few seconds on rapidly beating wings, then flying ahead 

 in undulating swoops. They are often seen in company with Lin- 

 nets, the two species frequently perching for many minutes in neigh- 

 borly manner on telephone wires. The bluebirds take wing one at 

 a time and fly ahead at the approach of an intruder, the different units 

 of a flock sometimes becoming quite widely scattered." 



Claude T. Barnes writes to me: "It is interesting to see them alight 

 upon snow-covered telephone wires. The snow bothers them, and 

 the flock will not alight until one of their number has ventured upon 

 the wire and shaken himself, thus jarring off the snow." 



