Final answer:
Female wood ducks have a behavior called brood parasitism, where they lay eggs in another duck's nest. This behavior is relatively rare but more prevalent when nesting boxes are used. The crowded nesting boxes lead to few eggs hatching.
Step-by-step explanation:
The subject of this question is Biology. It addresses the behavior of female wood ducks, specifically their tendency to lay eggs in another female wood duck's nest. This behavior is known as brood parasitism and it is relatively rare in natural nesting conditions, but can occur more frequently when nesting boxes are provided by humans. The crowded nesting boxes result in few, if any, of the eggs hatching.