It can be seen from the description of the call count procedure 
that this technique combines features of several methods. The spotting 
of singing birds is one of the most widely accepted methods used in 
making area population studies; and the numbers of birds seen driving 
between the call-counting stations is nothing more than a "roadside 
count" made in conjunction with the "call run." Birds flushed by the 
car when a call count stop was made, or birds seen during a stop to 
count calling doves, were birds which would not have been observed 
during a pure roadside count. Thus all of the methods tested supplied 
information of value in testing the practicality of the various steps 
developed in the call count method. 
Observations 
Roadside Counts.--In 1950 counts were divided into three categories 
(Table 1) because of the marked difference in the type of routes traveled, 
and because of the particular time of day. In some instances well- 
traveled highways were covered; while in others county roads and routes 
with no appreciable traffic were traversed. Category (c) contains birds 
recorded the first four hours after sunrise over roads equivalent to 
category (b). The data for category (c) were obtained in connection 
with calling counts which will be discussed later. 
From Table 1, it can be seen that observations made on roads away 
from heavily used highways give counts 54 times as high as those along 
heavily traveled routes. Likewise roadside counts made during the first 
four hours after sunrise produced 24 times as many birds as counts made 
later in the day. 
In 1951 a comparison of doves heard with doves seen during the weekly 
calling counts (Figure 1) indicates that doves were relatively incon- 
spicuous during that part of the nesting season up to about the 10th of 
July. After that date doves became increasingly more in evidence and 
eventually many more were seen than were heard. . 
During the weekly calling counts, doves which were seen at stops 
were separated into those which would have been observed even if the 
car had not stopped (Table 2) and into those which would not have been 
observed (included in trip totals in Table 3). Relatively little dif- 
ference was noted between these categories until about mid-June (Figure 2) 
which preceded the period when more doves were seen than were heard 
(Figure 1). An illustration of the difference in the categories mention- 
ed above is shown by the fact that on September 11, 1 doves were actually 
seen by one observer, while only 4 of this number would have been recorded 
if he had not stopped. Again on August 7, only 12 of 37 doves seen would 
have been recorded on a non-stop roadside count. 
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