The breeding population index for this unit showed a 
decrease of 6 percent in 1965 (table 1). That of hunting 
States declined 9 percent and of the nonhunting States, 2 
percent (figure 3). 
The 1965 index for the Central Unit is 11 percent less 
than the 10-year average (1955-1964) and 24.6 percent below 
the peak index of 1960 (figure,- 2) . 
Western Management Unit 
The index for the Western Management Unit decreased 14 
percent from 1964 which nearly nullified last year's gain of 
19 percent (table 1). The 1965 index is 2.5 percent below the 
10-year average (1955-1964) and 14.8 percent below the peak 
index obtained in 1959. 
Discussion of population index trends 
Breeding mourning dove population indexes for all manage¬ 
ment units decreased this year from the 1964 levels. Those of 
hunting States in the Eastern Unit virtually remained the same, 
but nonhunting States recorded a large population index decrease. 
The index for the entire unit is slightly below the 10-year aver¬ 
age (1.4 percent). The population index for the Eastern Unit 
has steadily decreased since 1960 except for a slight increase 
in 1964. The general decrease does not seem to be of a magni¬ 
tude to cause alarm. 
The indexes of both the hunting and nonhunting States of 
the Central Management Unit decreased, but index decreases 
from the hunting States were particularly noticeable. Since 
1957, there has been a general decline except for 1960. In 
contrast, nonhunting States of the Central Unit have generally 
shown increases over the same period. 
The Western Management Unit decrease was large (-14 percent) 
but the index remained close to the 10-year average (-2.5 percent). 
Among the Canadian provinces, Ontario and British Columbia 
have provided comparable dove population data to date. The aver¬ 
age numbers of doves heard calling on comparable routes increased 
in both provinces (24.6 percent and 3.8 percent, respectively) 
from the 1964 level (table 2). 
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