What is the main plot in the story "A White Heron"?

Sylvia is a nine-year-old girl who spends most of her life
wandering the woods near her grandmother's home near the Maine coast. Her only friend is
her grandmother's cow, Mistress Mooly, with whom she plays a game of hide-and-seek each
night. One day, she encounters a man in the woods, who is lost after a day's hunting. He
follows her home, and he spends the night. The man reveals that he is an ornithologist,
collecting specimens for his collection; he is specifically looking for a rare white
heron, one which Sylvia has seen in the woods. Together they go hunting for the heron
the next day, but they do not spot the bird. Sylvia develops a crush on the young
hunter, and she heads out early the next morning in hopes of spotting the heron. She
climbs a tree and, sure enough, she discovers its nest. But when she returns home to
join her new friend on another hunt, she fails to reveal the location of the nest and
the bird about which she has dreamed.