During May and June of 1951 the activity of calling doves closely 
paralleled that of June, July, and August of 1950. Table 8 shows the 
same gradual increase in activity with advancing daylight, but a drop 
during the second hour after. sunrise. Doves were found to call. less 
frequently with advancing daylight in 1951, as Table 9 indicates. The 
average calls per dove was greater in 1951 than in 1950; possibly the 
larger sample in 1951 gives a truer picture, for there is a definite 
correlation between dove populations and the rate of calling. 
More doves were observed while driving than while at stations in 
both 1950 and 1951. Table 10 summarizes the data demonstrating this 
for 1951 and also shows that most of the doves were seen during the 
first hour after sunrise. 
Comparison of 1950 with 1951 
Table 11 compares the average number of doves heard on repeated 
counts of 8 Ohio routes in 1950 with those heard on the same routes in 
1951. In 1950 there were 29 counts of these 8 routes which averaged 
18.2 doves per count, while in 1951 the 8 routes were counted 39 times 
and averaged 18.9 doves per count. Because counts were made in different 
months in the two years, single counts over each route in June of both 
years are also compared. The totals of these June counts show a slight~ 
ly greater population in 1951 although some individual counts give op- 
posite results. This indicates the need for conducting a sufficiently 
large number of counts in each area, or each state to obtain statistical- 
ly valid data upon which to base population fluctuations. 
While more doves were heard during 1951 than during 1950 there 
were fewer doves seen during 1951 on the same Ohio routes. Table 12 
gives a comparison of the averages of repeated counts of each route 
for the two years. When the June counts are compared the difference 
is not so pronounced, but they do show a decrease in the numbers of 
doves seen. 
Tables 11 and 12 show, also, that sight records vary more than 
counts of calling doves. The call count index seems to be subject to 
less variation and is therefore more reliable as a census technique. 
Further study of the data show that the production of young doves was 
evidently lower in June 1951 than in 1950, since the numbers of calling 
(breeding?) doves decreased slightly. Other studies in Ohio during the 
two summers indicated a later nesting season in 1951, but that the total 
production of young doves by the end of the summer was about the same 
as in 1950. This illustrates the danger of forecasting the total pro- 
' duction by counts made in May and June, when about half the breeding 
season still remains. 
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