BLUEBIRDS 
331 
Field Marks. A blue-backed bird with solid reddish throat, breast, and flanks. In 
young birds distinguished from the Mountain Bluebird by the deeper tone of the blue, 
most strongly suggested on wings and tail. 
Nesting. In hollow trees, posts, or stubs or in artificial nest boxes; nest of grasses. 
Distribution. Temperate eastern North America. In Canada, across the southern 
part of the Dominion commonly to Manitoba, more rarely in Saskatchewan. 
SUBSPECIES. The bluebird of eastern North America is the type form the Eastern 
Bluebird (l’Oiseau-bleu de l’Est) Sialia sialis sialis. 
With the Robin and the Meadowlark in the spring comes the Blue- 
bird, its brilliant coat shining like a jewel against the dead grass landscape, 
and its low, flowing warble giving promise of pleasant days. In the summer 
it nests freely in the bird-boxes in the garden, the fence-post out in the 
fields, or the old deserted flicker-hole in the telegraph pole by the wayside. 
In autumn its musical little warble is forgotten and it confines itself to a 
low voiced “ Purity-purity " usually heard coming mournfully down from 
birds passing high overhead and telling of the passing of summer. 
Economic Status. The Bluebird feeds mainly upon insects and is, 
therefore, highly beneficial. Weed seeds form an important part of its 
food and it eats some soft fruit, but practically no cultivated kind is taken. 
Hence the bluebird may be regarded as a consistently useful bird. 
767. Chestnut- backed Bluebird, l’oiseau-bleu a dos marron. Sialia mexicana. 
L, 7. Plate LIX A. Spring male: above from crown to tail, including face and throat, 
intense, deep purplish blue; more or less complete bar of chestnut across back and shoulders. 
Breast and flanks rich chestnut-red. Abdomen dull blue lightening to white under tail. 
Female: similar but duller and blue of throat replaced with slate-grey. Juveniles have 
back largely dark brown with many white flecks. Underparts spotted with rich brown and 
white. Throat slightly greying in general tone. Blue showing strongly only on wings 
and tail. 
Distinctions. A solidly blue-backed bird with more or less chestnut bar across 
shoulders and back, a blue throat, and red breast. Most like the Eastern Bluebird, but 
with blue throat instead of red, and the blue deeper and more purplish. The Mountain 
Bluebird is much paler blue and is solidly and completely blue. Adult Western Bluebirds 
are, therefore, easily recognized. Females with more or less red on breast are to be con- 
fused only with the Eastern Bluebird, but have a slate-grey throat. Juveniles lately from 
the nest are easily known from those of the Mountain Bluebird by the deeper blue on wings 
and tail, but probably with difficulty separated from the young Eastern Bluebird as the 
colouring at this age is practically the same; the Western bird, however, has usually a 
suggestion of grey tone on the throat. In practice, it is not likely that the Western will 
ever be confused with the Eastern as their ranges are not known to overlap. 
Field Marks. A bluebird with a red breast and blue throat. Young birds recognized 
from the Mountain Bluebird by the deeper tone of the blue suggested on wings and tail. 
Nestmg. In woodpecker-holes or natural hollows in stubs. It takes kindly to nesting 
boxes. 
Distribution. Western North America. In Canada, southern British Columbia. 
The common bluebird of the southwest coast. 
SUBSPECIES. The Western Bluebird (I’Oiseau-bleu de 1’Ouest), Sialia mexicana 
occidentalism is the Canadian form of the species. 
In general habit and appearance so like the Eastern Bluebird as to 
require no special discussion. 
768. Mountain Bluebird, arctic bluebird, l'oiseau-bleu des montagnes. 
Sialia currucoides. L, 7. Plate LIX B. Spring male: all solid, metallic, light sky-blue, 
paling on head and breast. Lower abdomen white. Female: with blue very much reduced ; 
head and back with blue veiled with ashy grey; underparts pale brownish ash, strongest 
on face and throat; blue showing clearly only on wings and tail. Juveniles lately from 
nest almost identical with parallel plumage of Eastern and Western Bluebirds. 
