48 THE One Ou SEMIEANNG Ale.) 
NESTING OF THE TREE SWALLOW. 
Tachycineta Bicolor. 
BY FRANK L. BURNS, BERWYN, PA. 
The Tree or White-bellied Swallow arrives early in April and 
departs in September. It has long been classed as a migrant in 
Chester County. Although it breeds in the adjoining county of 
Lancaster, it has but lately been classed as a rare summer resi- 
dent in this county. C. B. Ressel in his‘‘Birds of Chester County, 
Pa.,”’ published in the O:& O., Vol. XIV.,Nos. 7, 8 and 9, gives it 
as such; and B. H. Warren has observed them along the Brandy- 
wine several times, during the summer of ’89. All previous lists 
give it as a migrant. 3 
May 18,’S9, a friend and myself had the good fortune to dis- 
cover the completed nest of this bird in a railroad culvert at Val- 
ley Forge. The culvert is directly over a creek, which is the di- 
viding line between Chester and Montgomery Counties. At least 
three more pairs were skimming over the water, or resting on the 
telegraph wires. At this date the nest contained no eges; but re- 
turning twelve days later, it contained a handsome set of six pure 
white eggs, varying greatly in length, the first egg being almost 
SS* 
ad 
one tenth of an inch longer than the last one. The measurer 
a 
are as follows: .82x.59 3 77.505) s74x.50 59.72 5) cg 2 
f3X-53- B | 
The nest was placed in a crevice of the wall, the mortar having 
either fallen out or was dug out by the swallows, and was 
seven feet above the water and fifteen feet from the mouth 
of the culvert. The nest was composed entirely of dead 
grass and leaves. 
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