There are several "moods" of this story, among them suspense (in wondering if Sylvia will tell the hunter when she sees the white heron) and urgency (because of the hunter's desire to add the heron to his "collection"). The moods are conveyed through the use of the third-person omniscient narrator, who at times, seems detached but at other times seems very close to what is happening. There is a sense of immediacy there. Enotes states:
The narrator tells most of the story in the past tense, but three times shifts to present tense: when Sylvia first hears the hunter approaching (‘‘this little woods-girl is horror-stricken’’), when she has spotted the heron’s nest (‘‘she knows his secret now’’), and when she finds that she cannot reveal the secret (‘‘Sylvia does not speak after all’’). These moments give an immediacy that is sharp but that does not last. Each time, the narrator backs up again and stands at a distance.