In the Southern Drift Plains of North Dakota, land put into crop production has increased greatly over the last century. Of the approximately 70,000 square miles of land area in North Dakota, about 32,000 square miles are used for harvested cropland. Because of changes in the landscape, the diversity of habitat available for migrant birds has diminished, and migrants are now limited to choosing habitats for stopover sites that are uncharacteristic of those used at other times of the year. With reduced diversity of habitat a birds choice of feeding and resting areas greatly affects success at migration. Choice may depend on many factors including the tillage practices that occurred the preceding fall, the amount of food available within a field, the energy value provided by that food, habitat surrounding the field, and climatic conditions. These factors as well as type of crop will be analyzed to determine what migrants are using at a time when energy demands are high, surroundings are unfamiliar, and weather is unpredictable.
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