AN INTENSIVE ORNITHOLOGICAL SURVEY OF A 
TYPICAL SQUARE MILE OF CULTIVATED PRAIRIE 
ARTHUR R. ABER 
The present paper is a report on an intensive ornithological 
survey of a typical section of prairie farm land in northwestern 
Iowa. In making the survey several objects were in view. Be- 
sides merely making a census, it was hoped that some light might 
be thrown on the relation of birds to various crops, the effect 
of constant tillage on bird life, etc. It was thought that the 
exact data accumulated now would furnish a basis for comparison 
at a future time. With some such means of measuring the 
actual increase or decrease of the bird population, we will be in 
a better position to determine the problems of our bird life. 
Methods . — It was first planned to divide the section into twen- 
ty-four equal strips, extending east and west ; and it was expected 
that one trip through each of these strips would be sufficient to 
gather complete information as to the number of birds within 
its area. 
However, when the work was begun it was found that the 
birds were very unequally distributed, that certain areas were 
without any individuals, while other areas were densely populated. 
Consequently greater attention was given to the latter areas and 
less to the former, which consisted chiefly of corn-fields. It is 
possible that a very few birds may have been missed (not over 
half a dozen) in the corn-fields because of their being less care- 
fully worked. There was another chance for error in the region 
of the swamp; for here the slough grass was so dense and high 
that a few sparrows may have been overlooked. However, for 
the greater part of the section the results are reasonably accurate. 
T opography . — The section selected for the study is about three 
miles southeast of Sioux City, and forms a part of the W. A. 
Hickman farm. For identification its location is given thus: 
section 11, Woodbury township, T. 88 N., R. XLVH W. This 
particular section was chosen because it was believed to be typical 
of the upland prairie, as distinguished from the lowland prairie, 
or river bottom. It was the “rolling prairie” of the earlier days, 
when it was covered with the native prairie grass. The northeast 
