Many of Shakespeare's images recur throughout the play, Macbeth. Imagery helps the play maintain its dark and threatening tone. One of these images is the use of birds to mirror what is happening in the play and also to deepen understanding of the strangeness that has set upon the scene. .
When Lady Macbeth finds that Duncan will be staying overnight at their castle, she states, "The raven himself is hoarse that croaks the fatal entrance of Duncan under my battlements." The quote reveals the Lady Macbeth and Macbeth's plan to kill Duncan. The quotation is also important to the play in terms of tone. Ravens are generally recognized as evil, or as warnings of ill omen. A main theme of the play is addressing the dark side of human character, as expressed by what Macbeth does, and here the raven is described as being hoarse from declaring Duncan's doom. .
After Macbeth leaves the scene to murder Duncan, Lady Macbeth is waiting and listening. She hears an owl screech and says, "Hark! --- Peace. It was the owl that shrieked, the fatal bellman, which gives the stern'st good-night. He is about it." Once again, the quote illustrates the sense of foreboding that is thick in the air in the image of an owl's screech, said to proclaim death. Additionally, the reference to the "fatal bellman" refers to someone who tolls the bell the night before an execution is to take place. .
Shakespeare's usage of imagery enhances the mood at crucial points in the play, allowing readers to better understand the tensions arising in the situations the characters are in. Without quotes like the one about the owl's shriek, Lady Macbeth's apprehension would not have been as clear. .