FACTORS AFFECTING NESTING SUCCESS OF THE CANVASBACK IN THE ASPEN PARKLANDS

The Minnedosa study area is located in the southwestern portion of Manitoba just south of the town of Minnedosa. It is 90 square miles in size and roughly square in shape. The Aspen Parkland, in which the study area is located, is characterized by gently rolling terrain and black soils. Mixed farming is the rule with emphasis on small grain production consisting of wheat, barley, and oats. Roughly 50 percent of the water areas in the parkland are ringed with aspen, Populus tremuloides, and large blocks of aspen are interspersed throughout the area. The Minnedosa area differs because of more intensive farming practices which have reduced many of the aspen stands to small islands or bluffs, II or to trees ringing the shorelines. During the canvasback nesting seasons of 1961-65, the number of ponds per square mile averaged about 60, but some sections contained as many as 120 ponds. Average pond size was 1.1 acres. About 15 percent of the water areas had one- third or more of the shoreline covered by aspen and willows with some burr oak, chokecherry, and pin cherry. Whitetop, Scholochloa festucacea, was the most abundant emergent aquatic and usually made up about 40 percent of the emergent cover on the area

FACTORS AFFECTING NESTING SUCCESS OF THE CANVASBACK IN THE ASPEN PARKLANDS

The Minnedosa study area is located in the southwestern portion of Manitoba just south of the town of Minnedosa. It is 90 square miles in size and roughly square in shape. The Aspen Parkland, in which the study area is located, is characterized by gently rolling terrain and black soils. Mixed farming is the rule with emphasis on small grain production consisting of wheat, barley, and oats. Roughly 50 percent of the water areas in the parkland are ringed with aspen, Populus tremuloides, and large blocks of aspen are interspersed throughout the area. The Minnedosa area differs because of more intensive farming practices which have reduced many of the aspen stands to small islands or bluffs, II or to trees ringing the shorelines. During the canvasback nesting seasons of 1961-65, the number of ponds per square mile averaged about 60, but some sections contained as many as 120 ponds. Average pond size was 1.1 acres. About 15 percent of the water areas had one- third or more of the shoreline covered by aspen and willows with some burr oak, chokecherry, and pin cherry. Whitetop, Scholochloa festucacea, was the most abundant emergent aquatic and usually made up about 40 percent of the emergent cover on the area