sides.
The birds are on the wing during the greater part of the day, generally
not frequenting the vicinity of their nesting site, but returning toward
dusk, when they may

[Illustration 271: Chimney Swift.]
[Illustration: E. R. Forrest. NEST AND EGGS OF CHIMNEY SWIFT.]
[Illustration: right hand margin.]

Page 270

be seen to, one at a time, dive headforemost into the tops of chimneys.
The nest is made of small twigs firmly glued to the sides of the
chimney, or tree, and to each other, with the glutinous saliva of the
bird, making a narrow semi-circle platform for the reception of their
three to five white eggs which are deposited in May or June; size .75 x
.50.

424. VAUX'S SWIFT. _Chaetura vauxi._

Range.--Western United States, chiefly west of the Rockies; breeding
north to British Columbia, and wintering south of the United States.

Similar to the last but smaller (length 4.5 inches), and paler in color,
fading to white on the throat. The habits of this species are like those
of the eastern Chimney Swift, except that the majority of these species
still continue to use hollow trees as nesting places. The eggs are just
like those of the last bird.

425. WHITE-THROATED SWIFT. _AEronautes melanoleucus._

Range.--Western United States south of Canada, and chiefly in the Rocky
Mountains, and in California ranges, north to Lat. 38 deg..

A handsome species, 6.5 inches in length, with blackish upper parts and
sides, and white throat, breast and central line of under parts, flank
patches and ends of secondaries; tail feathers not spined or stiffened.
These birds are fairly common in some localities within their range, but
appear to be found only on high ranges or in their immediate vicinity.
They nest in crevices and caves in the face of cliffs, making a nest
similar in construction to that of the Chimney Swift but of weed stalks
instead of twigs, and lined with feathers. They lay four or five dull
white eggs, during June or July; size .85 x .50.

[Illustration 272: White.]
[Illustration: White.]
[Illustration: 425--426.]
[Illustration: White.]
[Illustration: deco.]
[Illustration: left hand margin.]

Page 271

HUMMINGBIRDS. Family TROCHILIDAE

Hummingbirds have been truly called "Winged Gems." They are the smallest
of birds, the usual plumage being a metallic green with throat or crown
patches of the brightest of iridescent shining red, orange, blue or
violet. Their nests are marvels of architecture