4 March 1948
Mr. James W. Kimball
Dept. of Game, Fish and Parks
Pierre, South Dakota
Dear Jim:
I was very pleased to read your MS and I am very sorry
that Aldo could not reAd it just now. Ae handed it to me
yesterday asking that I read it and comment on it to you. I
have penciled a few remarks directly in your copy which I am
returning.
Briefly here are a very few notes: I think you would
improve your naper by cutting out fractions. You imply lab-
oratory refinement which I'm sure you do not claim. In tables
where the total must equal 100 use them, but I question their
use in the text.
.I think you have very probably underestimated density in
relation to frequency and occurrence of crowing. We have scme
data that shows the rate of crowing going down with increasing
density. You touch on this subject on nages 17 and 21, but I
don't think you clarify the possibility of this factor. In this
connection, why not use a large holding field say 40 acres. Put
a known number of wing-clipped or brailed cooks into the field.
Then in a second field introduce a significantly larger Froup
to sioulate higher density in the field. Kno"7ing the density in
each field it would then be rather simple to test crowing by these
cocks during the time of season and hours of day that you use.
You could also use these fields to measure distance of audibility,
accuracy of your technique, and even determine how possible it is
to work out an actual census.
I sugrest writing out per cent in text and using % in tables
or captions under figures and tables only.
I'm not sure that I can agree with everything you say regarding
obstruction of sound, p. 15. The "acoustic clouds" you mention are
likely ionized clouds, and the degree of ionization will detrrmine
the amount of interference. This is very similar to radar inter-
ference and performance (I was radar officer for Navy on carrier)
which can cut down performance to near zero. These also affect
radio transmissions and the height of such clouds is generally
well established. Aowever, radar has been shown to affect bird
migration and attract certain birds such as homing pigeons which
have been obsorvekc circling a radar tower. I have seen them

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