In the afternoon or evening the best time for calling seemed to be 
the two hours preceding official sunset. In the York-Lancaster region 
and in Erie County, Pa., both areas (1950) averaged 20 calling birds 
per 100 stops (based on 80 samples) in the last two hours before sunset. 
On the other hand, counts made during the first two hours after sunrise 
in these same areas yielded 65 birds and 60 birds per 100 stops, respective- 
ly (based on 177 samples). It can be seen that, in these areas, morning 
counts were at least three times more productive of calling birds than 
evening courts. 
In the 195] counts in Maryland and Virginia we were indeed fortunate 
that no censuses were postponed because of such adverse weather factors 
as wind and rain, although on May 8 wind could have been responsible for 
the low counts. Starting temperatures ranged from 32 degrees on April 5 
and 22, to the mid-seventies on July 2h and August 21. Cold weather, as 
such, had no apparent effect on calling activities since several of the 
highest weekly counts were recorded during the coldest mornings. The 
warmest weather, of course, was during July and August, but the decline 
in calling activities during these months is probably not associated with 
the seasonal temperature increase, but rather with the decline in breeding 
activity. 
Calling activities during the 1951 nesting season showed relatively 
high peaks and low depressions during April and May, and a plateau in the 
month of June (Figure 3). The average number of calling doves for May was 
smaller than either April or June as shown in Table 10, and with little 
difference between these latter months. A drop is noticed after the Jwly 3 
-eensus and the noticeable decrease in calling activities continued until 
September 11 when no doves were recorded calling. Data showing the actual 
number of doves calling on each weekly trip are given in Table ll. 
Table 10.--Calling Doves by Months and Routes 
{Trips Average 
Months Route 1 Route 2 Route 3 Total per month per trip 
april 63 47 1)0 11 (12.7) 
May 68 43 149 15 ( 9.9) 
June. 59 50 Wy 11 (12.8) 
July 82 35 120 10 (12.0) 
Sept. Oo. 3 3 h ( 0.75) 

29 
