In hunting States of the Central Unit, the breeding index 
decreased 4 percent compared to 1961. ‘The State of Texas had 
two routes that were not considered in the 1962 data because 
they so heavily weighted the data for Texas that the State 
index was altered -22.6 percent (from +4.3 to -18.3 percent 
change). This in turn altered the entire Central Management 
Unit data (from -11.5 to -15.8 percent change). 
In nonhunting States, the index declined 20 percent between 
1961 and 1962 (table 1). Adverse weather was reported as occur- 
ing during the census period in the north central area of this 
management unit in 1962. To test the influence that unseasonable 
weather had on these counts, the records of weather conditions 
taken at the time of beginning of the routes was compared for 
the years 1961 and 1962 in the States of Iowa, Minnesota, 
Nebraska, South Dakota, and North Dakota. Average temperature, 
percent cloudiness, and the Beaufort wind scale were measure- 
ments used. No clear-cut weather differences were noted 
between years except greater cloudiness occurred in 1962 
reflecting the reported stormy conditions. Cloudiness, by 
itself has not proven to be a cause of decreased calling 
intensity. 
Western Management Unit 
The breeding population index for the Western Unit showed 
a 12 percent decrease from the 1961 level (table 1). Figure 
2 shows that the breeding index of the Western Unit has fluc- 
tuated moderately over the 10-year period at generally stable 
levels. 
Discussion of Population-index Trends 
Indexes to mourning dove breeding populations in the three 
management units showed declines from the 1961 level. For the 
United States as a whole, the 1962 breeding population index 
was 10 percent below the 1961 level. The long-term trend has 
been generally upward since 1953 to 1960 and has decreased in 
1961 and 1962. The breeding population index level in the 
Kastern and Central Units remain above the 1953 levels and in 
the Western Unit the index fluctuated above and below its 
present level since 1953. 
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