Agricultural Extension Program Plan of Assesment 1979. W.F Cowan
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TextPublication details: MB : 1979Abstract: The most productive duck breeding habitat in North America occurs coincidentally with privately owned farmland in the fertile soil zones of Western Canada's prairies and parklands (Canada Land Inventory 1979).Although this region comprises only 10% of the breeding range of North American ducks, it harbours nearly one-half of the breeding population,with an average duck density three times that of the remaining breeding ranges (Pospahala 1974). Changes in production of young here influence major changes in the continental population. Duck populations are historically strongly correlated with climate, declining during drought and recovering during wet periods. During the drought of the early 1960's, the continental population was reduced by about 50%, with greatest reduction in southwestern Manitoba and south-eastern Saskatchewan (Pospahala 1975). A ten year period of abundant moisture followed, a relatively lengthy one, but the population recovered by only 25% in this time (Brace and
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The most productive duck breeding habitat in North America occurs coincidentally with privately owned farmland in the fertile soil zones of Western Canada's prairies and parklands (Canada Land Inventory 1979).Although this region comprises only 10% of the breeding range of North American ducks, it harbours nearly one-half of the breeding population,with an average duck density three times that of the remaining breeding ranges (Pospahala 1974). Changes in production of young here influence major changes in the continental population. Duck populations are historically strongly correlated with climate, declining during drought and recovering during wet periods. During the drought of the early 1960's, the continental population was reduced by about 50%, with greatest reduction in southwestern Manitoba and south-eastern Saskatchewan (Pospahala 1975). A ten year period of abundant moisture followed, a relatively lengthy one, but the population recovered by only 25% in this time (Brace and