274 
MICRO PODIIFORMES 
Nesting. In a beautiful structure, covered with bits of lichen cemented together with 
cobweb, saddled on the top of a branch. 
Distribution. Eastern North America. In Canada, west to Alberta, probably to 
the foothills. The hummingbirds of Alberta have not been carefully identified. 
Hummingbirds fly forwards, backwards, sideways, or remain perfectly 
stationary in the air with equal ease — another instance of parallel develop- 
ment — a bird flying like an insect yet in structure strictly bird-like. The 
wings vibrate with a rapidity that can be measured only by the tuning- 
fork method used with insects. This system of flight is fundamentally 
different in method from that of other birds and consequently the wings 
differ from the usual type. They are long, narrow, and non-flexible, and the 
keel of the sternum is immensely deepened to give support to the great 
muscles that move them. In proportion to its wing-spread a humming- 
bird has a breast keel nearly three times larger than that of a pigeon, a bird 
of average flight, or forty times larger than that of an albatross. 
Economic Status. When it is remembered that some of the smallest 
insect pests are the most destructive, we can realize that possibly the 
economic importance of the hummingbird may be greater than suspected. 
Besides nectar, its food seems to be composed of small flies, gnats, minute 
bees, wasps, and other flower-haunting and pollen-eating forms. Appar- 
ently no harm can be charged against the species and it may do good out 
of all proportion to its size. 
429. Black-chinned Hummingbird, l’oiseau-mouche a menton noir. Archilo- 
chus alexandri. L, 3*50. A small hummer. Male: metallic bronzy green above, dull 
whitish below. Throat and gorget black with purple-violet reflections on its lower edge. 
Female: similar, but with dull white throat. 
Distinctions. The male, with its black throat and gorget not elongated or projecting 
at the sides, is very distinctive; but the female and young birds are quite like similar 
plumages of the other Canadian hummers. There is little geographical likelihood of con- 
fusion with the Ruby- throated. From the Rufous it may be easily separated by its lack 
of any rufous suffusion. From the Calliope by its larger size, solid dark throat in the male, 
and entire absence of rufous in the female. 
Field Marks. The black throat and gorget are a certain recognizable field mark for the 
male, but it must be remembered that these jewel-like gorget colours in other species only 
flash out when viewed from particular angles, and from many directions they show as 
black. Females do not show ruddy on flanks and undertail as do the Rufous and Calliope 
Hummers. 
Nesting. Nest a beautiful structure of vegetable down and cobwebs saddled on a 
branch. 
Distribution. Western North America, from British Columbia to northern Mexico, 
east to Montana. In Canada, only on the coast and in the interior of southern British 
Columbia. Not so far noted on Vancouver Island. Most common in the interior valleys. 
A rare and rather local little hummer. 
433. Rufous Hummingbird, l'oiseatt-mouohe roux. Selasphorus rufus. L, 
3-50. Plate XXXVI B. Male: all above bright, brick-red, not iridescent except for 
slight green reflections on crown. Red suffuses over underparts leaving band below gorget 
white. Throat and gorget fiery red. Female and juveniles: bronzy, iridescent green 
above, with base of tail rufous at sides; below, dull white washed with rufous on flanks 
and undertail-coverts. Usually irregular spots of flaming iridescence on throat. 
Distinctions. The male with its red back and flaming gorget, elongated and projecting 
at the sides like a shield, is unmistakable. The large amount of rufous wash on the body 
will identify the female and young birds from the Black-chinned, but they may be difficult 
to separate from similar Calliope Hummingbirds even when in hand. 
Field Marks. As above distinctions. 
Nesting. Nest a beautiful structure of lichens and cobwebs saddled on a branch. 
