Plate XXV. 
Fig. 2. POLIOPTILA G/ERU LEA— Blue-gray Gnaicakher. 
This species is next in size to the Ruby-throated Hummingbird. It arrives, according to Dr. Langdon, 
April 10th, and departs September loth. The nest is constructed between the first and the last of May. 
When two broods are reared, as is frequently the case, a second nest is built in July. 
LOCALITY: 
Tall trees along the banks of streams, sides of ravines, and in woods without much underbrush, are 
the usual nesting places. Sometimes trees along country-roads are selected. I have never known the 
nest to be built in towns, though it is probable that it is at times, as the birds are apparently very 
tame and unsuspicious. Dr. J. M. Wheaton, in his forthcoming report on the birds of Ohio, says of P. 
cserulea : “For their summer home they choose a side of a ravine, or a glen, or glade in mixed woodland.” 
POSITION : 
The nest is saddled upon a small branch, which is horizontal or nearly so, at such a point that it 
receives the support of one or more small twigs at the base or side. Its distance from the ground varies 
from ten to fifty or sixty feet. Its distance from the trunk varies with the kind and shape of the tree 
upon which it rests, and also with its distance from the ground. Usually, however, it is nearer the ex- 
tremity of the limb than the trunk of the tree. 
MATERIALS : 
The foundation and superstructure are composed of very fine vegetable fibres and slender pieces of 
roller-grass, intermixed with plant-down and various soft vegetable materials rolled into irregular pellets 
or felted in with the fibres. The lining is sometimes made of the same substances as the superstructure, 
but usually it consists of a thin but compact layer of soft plant-down, white, dun-colored, or reddish-brown. 
The down from willow-blossoms, and cotton-trees is frequently employed. Occasionally a nest is lined 
with more or less horse-hair or small feathers. Externally the structure is covered with scaly lichens, 
grayish-colored ones are ordinarily used. These lichens are fastened by web in the same manner as those 
on the Hummingbird’s nest. Some nests are uniformly and beautifully covered, in others less care is 
taken. One specimen before me is not more than half covered, and that is slovenly done; while the 
nest illustrated rivals in workmanship and beauty its smaller companion. The thickness of the walls 
differs considerably in different nests; the external dimensions, therefore, are subject to greater varia- 
tions than the cavity. The average external diameter, mid-way between the rim and base, is about two 
and one-half inches. At the rim it is a little less, and at the base a little more. Sometimes the aver- 
age central diameter is as great as three and one-half inches. The external depth varies from two to 
three and one-half inches, usually it is about the same as the diameter. The cavity at the rim aver- 
ages about one and one-fourth inches; an inch below the rim it increases to about one and three-fourths 
inches; from this measurement it varies but little. The depth varies from one to two inches; average 
about one and one-half inches. 
101 
