In Charlotte Brontë's novel, Jane Eyre, the difference uses of bird imagery can reflect both power and crime.
In the beginning of the novel, after Jane has arrived to work as a governess at Thornfield, she is shy, retiring, and gently spoken. Rochester, the owner of the estate, is a dark, brooding and somewhat frightening figure to Jane who has spent many years of her life being repressed and controlled by the headmaster at Lowood Institution. Jane is still afraid and stays hidden like a frightened bird.
Rochester is not cruel, but he is powerful, and seems to entertain himself at Jane's expense, ofter referring to Jane as a frightened bird, who keeps her real feelings hidden, who might fly under the right circumstances. He notes:
I see at intervals the glance of a curious sort of bird through the close-set bars of a cage; a vivid, restless, resolute captive is there; were it but free, it would soar cloud-high. (Chapter 14)
Rochester is right in noting that Jane is timid, and that she could soar if given the opportunity, but early in their relationship, he does not provide Jane with the confidence she needs to "soar."
The irony in Rochester's treatment of Jane is that at the beginning he does control her by exerting the sheer power of his personality over her. However, after some time, his tutelage is what will allow her not only to fly, but to be strong enough to leave him.
Jane is imprisoned like a caged bird when Rochester embraces her to kiss her, holding her captive in his arms. However, he has been a fine teacher—perhaps without knowing it—as she announces that she is not a trapped little bird without the ability to free herself.
I am no bird; and no net ensnares me; I am a free human being with independent will, which I now exert to leave you." (Chapter 23)
In these instances we have seen Rochester treat Jane like a helpless bird, exerting his power over her. Finally, she comes into a sense of her own strength, enough that she can leave him when she must. These images support the themes of "independence" and "search for home and family" for Jane.
Bird imagery, however, is also seen in terms of crime, in the person of Bertha, Rochester's insane wife, who he keeps locked in a tower, cared for by Grace Poole. Bertha is like an eagle, a bird of prey. She lives in the tower, the highest spot in the castle where she presides over much of what occurs at Thornfield. In one instance, she breaks free of her overseer, and sets Edward Rochester's bed curtains on fire. It is Jane who saves him.
Later, when Bertha's brother comes to visit, she attacks him, like a predator, an eagle, wounding him seriously. In some ways Edward could be seen as an eagle as well, with his keen insight and careful observance of all that occurs at Thornfield. However, where Edward demonstrates power, it is Bertha who commits crimes through her madness; not as a gentle bird, but as a predatory creature, like an eagle.
And it is Bertha who, eventually sets fire to Thornfield, killing herself in the process, yet another example of the bird imagery of an eagle, a bird of prey, bent on destruction and crime, albeit unknowingly.