Final answer:
The raven did not fly off according to the provided text, which describes it as speaking only a single word, 'Nevermore,' and remaining on the bust without fluttering a feather.
Step-by-step explanation:
The question refers to a narrative context, most likely pertaining to a story, poem or a fable. In the excerpt provided, the raven is mentioned to speak only one word, "Nevermore," and does not leave, hence it does not fly off. The dove, on the other hand, is mentioned in a different context where it takes possession but is not specifically stated to have flown off and not returned. Therefore, by analyzing the provided excerpts, the answer can be inferred as the raven. This is based on the passage which says that the raven "spoke only, That one word, as if his soul in that one word he did outpour. Nothing further then he uttered - not a feather then he fluttered." It lacks any mention of the raven flying away, in contrast to the typical behavior displayed by other birds in the passages. However, since the swallow was not mentioned in the given text, it may be part of a broader context not provided here.