Sylvie's moral dilemma is whether to reveal to the young hunter the location of the heron's nest. This decision is bound up with other feelings that she has about her life in the woods and her distrust of other people. Although her action is to take no action, to say nothing, by withholding the information, she is not only depriving her family of ten dollars, but she is also making a decision about what sort of life she wants to lead. Her loyalty to the heron is a metaphor of her love of family; in allowing the bird to be destroyed, she would also in a sense be destroying herself.
The climax of the plot comes when Sylvie climbs the old pine tree to find out where the heron lives. This climb is also a metaphor for Sylvie's own imagination. From the top of the tree, she can see everything, including the sea; the boundaries of her life in the woods fall away, and she experiences a profound sense of oneness, of belonging to the landscape she sees. It is a kind of secret knowledge for her, and when the heron perches in he tree near her, it is as if to acknowledge that Sylvie and the bird are bound by this same secret. It is this realization of her place that causes her to remain silent about the nest.