Area Population Studies.--Population studies based on repeated 
censuses and searches for nests were conducted in seven (7) study 
areas of three different types. Table 7 gives a summary of doves 
found in each study plot and the total man-hours required to obtain 
these data for each area. 
Abandoned apple orchards were first selected but the results 
from the two areas in Maryland and Pennsylvania seemed so poor that 
other habitats were chosen for most of the subsequent studies. Re- 
sults from rural cemeteries gave better data and in much less time. 
Furthermore, the finding of nests was easier in cemeteries because 
of the relatively small number of trees that were suitable for nest- 
ing sites. In an orchard of 125 acres there normally are 1,000 or 
more mature trees which are potential nesting sites. Obviously much 
time would be required to examine each tree for nests. The average 
density in the three cemeteries was 54 pairs of doves per 100 acres 
while it was only a4 pairs per 100 acres in three abandoned apple 
orchards. Not only was the actual density much greater in rural 
cemeteries but, as stated above, nests were much more readily found, 
and census work was completed in much less. time. 
The only sample of a suburban residential study area also was 
much more productive than apple orchards as far as dove populations 
were concerned, but nests were difficult to locate. 
Call Counts.--Tables 8 and 9 present the data on the number of 
calling birds and the number of times each bird called during a 3-minute 
period in 1950. They have been arranged according to localities and 
time of day with respect to official sunrise. They indicate that there 
was a definite regularity in the decrease in the number of calling birds 
as the day progressed and a noticeable irregularity in the number of 
times each bird called in the 3-minute periods. 
The largest number of pre=sunrise samples was obtained in western 
New York under optimum conditions; these data indicate then, that more 
doves were calling in the period (1/2 - 3/4 hour) before sunrise than 
during any other observation period. The relatively high counts in the 
first hour after sunrise in York, Lancaster, and Erie Counties, Pennsylvania, 
are more in line with observations made in 1951 in Maryland and Virginia. 
In the case of Long Island, the small number of samples, together with 
unfavorable habitats visited before sunrise seemed to be the factors 
contributing to a low count in the pre-sunrise period. 
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