THE OOLOGIST 69 
History of a Double Nest 
of the Yellow Warbler. 
While climbing over a fence, one 
day in May 1899, I noticed in a Wild 
Rose bush at my feet a nest of the 
Yellow Warbler. It was placed about 
three feet from the ground and some 
ten cr twelve feet from the shore of a 
small pond and appeared to be com- 
pleted, but held no eggs. 
Passing by the spot again at noon 
on the 17th I glanced into the nest 
and saw one egg of the Cowbird, but 
none of the rightful owners. Curious 
to see how the Warblers would treat 
this intrusion into their home I return- 
ed at 1:30, but the egg was nowhere 
in sight. Closer examination showed 
that a thin layer of plant fibres had 
been laid over the egg; in fact the be- 
ginning of a second nest. The birds 
must have worked very rapidly to 
have secured enough material to en- 
tirely conceal the egg in so short a 
time, but during the rest of the after- 
noon I watched them at their nest 
building and found they worked con- 
tinuously without resting. 
Procuring some soft cotton, I fas- 
tened it to the twigs of a nearby bush 
and retired to a tangle of Wild Grape- 
vine to watch. Hardly had I conceal- 
ed myself when the male appeared and 
sang from a sappling just over the 
nest. The female appeared a moment 
later and flew directly to the cotton, 
fluttering before it and tearing off lit- 
tle tufts which were woven, or rather 
matted into the nest. At no time did 
the female alight to tear off the cot- 
ton, but on each trip poised in the air 
before it, much as a Hummingbird 
does in front of a flower. Generally 
three or four strips were carried to the 
nest each visit. 
Arriving at the nest with a beakful 
of cotton the female settled down into 
the nest, turning around and tucking 
in little bits here and there, shaping 
the sides and rim with her breast and 
bill, and matting the whole into a 
solid feltlike substance. No time was 
wasted at the nest however, and in a 
few minutes she was back after more 
material. 
While the female was thus busily 
employed, the male flitted from bush 
to bush, caught an insect here and 
there, sang, now in the trees overhead, 
now from the bushes near the nest, 
but only once or twice did he visit 
the nest. On these visits he did not 
appear to be carrying any material 
for the nest. It was probably simply 
a tour of inspection and as if satisfied 
with the way the work was progress- 
ing he finally disappeared and it was 
nearly an hour before he came back, 
announcing his return by singing in 
the trees overhead before descending 
to his mate in the bushes below. 
By sunset the second nest was to all 
appearances completed, but when I 
visited it again next morning I found 
that the birds had worked in a quan- 
tity of buff colored vegetable fibres, 
not materially increasing the bulk of 
the nest, but toning down the white- 
ness cf the cctton and rendering the 
structure much less conspicuous than 
it had been the night before. The nest 
was now complete and a vacation of 
several days followed before the eggs 
were laid. Had the birds been com- 
pelled to procure their nesting ma- 
terial in the regular way instead of 
having a supply so conveniently fur- 
nished them, the building of this sec- 
ond nest would doubtless have taken 
much longer. 
The first egg was laid May 23d and 
one was deposited each succeeding 
day until four had been laid. Incu- 
bation began at once and lasted ten 
days, the young appearing on the 5th 
of June. For the first few days their 
growth was rather slow, but both 
parents fed them constantly, the fath- 
