530 Birds of Colorado 
in winter will bring up a wave of migrants even in December or January, 
but as a rule they are driven back by storms to the south again. Lowe 
(01) believed that they wintered in the State near Pueblo, and Cary 
found it common at Springfield and Gaume’s Ranch in late November, 
and was told that it wintered there. It has been noticed breeding 
on the slopes of Mount Lincoln at timber line, at about 13,000 feet, 
by Allen, at various elevations from 8,000 to 10,000 feet near Gold 
Hill, in Boulder co. (Gale), and in the suburbs of Denver (Dille & 
Minot) and Colorado Springs ; while on the western slope, in Mesa co., 
it is stated by Rockwell to be a common summer resident, breeding 
from 5,000 to 7,000 feet in the cedars. At Fort Lewis, in the extreme 
south-west, it was found by Gilman to be very abundant, nesting in 
boxes and about houses of that place. In most parts of Colorado 
it departs for the south in flocks at the end of November, or even the 
beginning of December. 
Habits. —The Mountain-Bluebird comes north in flocks 
of considerable size, so that it can be easily recognized 
when migrating. It is found chiefly in open country, 
‘and likes to perch on rail fences alongside fields and 
pastures. It feeds on insects and wild berries in the 
season. Its note is rather mournful and plaintive, more 
so than that of the eastern bird. 
It builds its nest naturally in old Woodpeckers’ holes 
or the stubs of dead trees, sometimes, according to Gale, 
excavating a cavity for itself. The height of the nest- 
hole varies from about four to twenty feet, but is usually 
about twelve. The nest is constructed of dried grass, 
and is a bulky affair; it is sometimes lined with 
a few feathers, but is more often without a special 
lining. 
The eggs, usually six in number, are pale greenish- 
blue, and measure about °85 x ‘65. Dennis Gale found 
fresh eggs chiefly between May 25th and June 25th, 
but on one occasion he took a nest with five fresh eggs 
on April 28th, while a pair observed by Dille (94) had 
laid a full complement of seven in a nesting-box by May 
5th in Denver. 
