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IOWA ACADEMY OF SCIENCE Vol. XXVIII, 1921 
When this report was investigated it appeared entirely logical 
that these orioles had built in the soft maples, even though their 
natural preference might still have been for the elm, for in some 
parts of the town no elms are found for a few blocks. It was 
also interesting to note that although the number of hard maples 
practically equalled the number of elms, there were but two nests 
found in hard maples. The orioles evidently chose the wide- 
spreading trees, and in almost every case they hung the nests 
at the very end of a flexible outer branch. 
As it was thought possible that the nests might have been hang- 
ing for several seasons, each student concerned in the census tak- 
ing was asked to use his own judgment in determining whether 
or not the nests were more than one year old. It was the general 
opinion that about one-half of the nests counted had been built 
during the preceding summer as they seemed to be in quite good 
condition, and the conclusion was drawn that between fifty and 
sixty pairs of Baltimore orioles nest yearly in Mount Pleasant. 
The other half of the nests appeared to be of two or three years’ 
standing. Most of the third year’s nests had probably disappeared 
entirely but several cases were reported where in one tree three 
nests were found ; one very old and almost weathered away, one 
less battered but still showing wear, and one in good condition. 
They evidently represented three years’ residence, and demonstrat- 
ed the fact that orioles come again year after year to any favorite 
locality. 
Later in the season, after the returned orioles had nested and 
the young broods had been reared the search for nests was re- 
newed with the hope that perhaps four seasons’ nests might be 
found together. However, though considerable time was spent 
in this search, it served chiefly to demonstrate the advisability of 
hunting orioles’ nests -during the winter months. The birds show 
admirable skill in concealing their nests from the casual ob- 
server. One new nest was obtained which hung from the lowest 
branch of a hackberry tree thirty feet directly above the side 
walk. It was cut down, and its structure and materials were 
examined. Its outer walls were made chiefly of silklike plant 
fibers in/terwoven with a few black horse hairs, and it was hung 
by loops of the same material from two small branches at the 
end of the limb. Its interior measured five inches in depth and 
about three inches in width. Its upper walls were thin, soft, and 
pliable, but the bottom was an inch and a half thick and very 
firm and solid. This substantial flooring was found to consist 
