Sunflower, due to the easy accessibility and high nutritional value of its seed, is particularly vulnerable to damage by birds (Figure 101). Seeds are exposed and the large head serves as a perch during feeding. Sunflower seed is a preferred bird food because the seed contains many proteins and fats essential to their growth, molt, fat storage and weight maintenance processes. Although many species of birds feed in maturing sunflower fields, the greatest losses are caused by migrating flocks of red-winged blackbirds, yellow- headed blackbirds and common grackles (Figure 102). Significant losses can occur in fields near cattail marshes.
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