The rising action of the story begins when the hunter, a representative of the story's antagonist -- society -- happens upon Sylvia in the woods. Tension begins to build at this point because she fears him; she is "horror-stricken to hear" his whistle and she thinks of him as somewhat "aggressive," not like her animal friends, but an "enemy." The hunter begins to win her over, presenting her with gifts and promising riches, and when she climbs the great pine tree in part II, she does so with the intention of spotting the heron so that she can direct the hunter to its nest.
However, in the climax -- the moment when the hunter is expecting her to tell -- she cannot "tell the heron's secret and give its life away." This the moment of greatest tension in the story: "No, she must keep silence! What is it that suddenly forbids her and makes her dumb? Has she been nine years growing, and now, when the great world for the first time puts out a hand to her, must she thrust it aside for a bird's sake?" She remembers the beautiful tree, the lovely bird and the golden air, and she will not speak.
The falling action consists of Sylvie's disappointment after the hunter leaves, later hearing his gun farther off in the forest, and Sylvie's memory of the dead birds, covered in blood, birds that he claimed to love.