. Bulletin. Natural history; Natural history. August, 1961 Bellrose et al: Sex Ratios and Age Ratios 461 in the bags of Illinois hunters revealed a spectacular rise in production by the mal- lard; the rise occurred even though spring temperatures were below^ normal. The spectacular increase in production con- tinued in 1948, as vrater conditions in Canada improved. In 1949, vt^ater condi- tions in Saskatchew^an w^ere poor, and mallard production dropped drastically. In 1950, water conditions were excel- lent in both Manitoba and Saskatchewan. May of 1950, however, was unusually cold and wet. M
. Bulletin. Natural history; Natural history. August, 1961 Bellrose et al: Sex Ratios and Age Ratios 461 in the bags of Illinois hunters revealed a spectacular rise in production by the mal- lard; the rise occurred even though spring temperatures were below^ normal. The spectacular increase in production con- tinued in 1948, as vrater conditions in Canada improved. In 1949, vt^ater condi- tions in Saskatchew^an w^ere poor, and mallard production dropped drastically. In 1950, water conditions were excel- lent in both Manitoba and Saskatchewan. May of 1950, however, was unusually cold and wet. Mallard production, as in- dicated by age ratios of ducks bagged in the Mississippi Flyway, declined. In 1951, water conditions were good through the breeding season in Saskatchewan and fair in Manitoba; a major water loss oc- curred in Manitoba. In that year, mallard production increased considerably. The two provinces differed materially in water conditions in 1952. In Manitoba, rapid disappearance of water areas began in April and continued through the summer; by August waterfowl conditions were the worst known since breeding grounds ob- servations were started. In Saskatchewan, water conditions were favorable through- out the breeding season. Mallard produc- tion in 1952 declined very little, if at all, age ratios of bagged ducks indicated. In 1953, water conditions were excellent in Saskatchewan and fair to good in Mani- toba. There was no water loss during the season in Manitoba and only a slight loss in Saskatchewan. Despite these favorable water conditions, age ratios of bagged ducks revealed a decline in the production of mallards in 1953. Although small water areas in Sas- katchewan and Manitoba were almost at maximum numbers in 1954, age ratios indicated only a slight increase in mallard production, fig. 22. In 1955, with a further increase in number of ponds in Saskatchewan, but with a sizable decrease in the number in Manitoba, mallard pro- duction increased materia
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