The first-person narrator of the poem acts as an empathetic observer. Rather than experiencing physical imprisonment, the speaker understands the emotional and psychological toll of confinement. The narrator connects their own painful experiences of restriction with the captive animal's desperate struggle, using lyrical language to voice a shared yearning for liberty.

The central figure of the poem's extended metaphor is an animal trapped inside a metal enclosure. It watches the natural world outside and batters its wings against the metal until they bleed. When physical resistance fails, it resorts to singing, though this song functions as a desperate prayer for deliverance rather than a joyous melody.

An unnamed, off-page figure responsible for building the cage and maintaining the bird's captivity. By replacing the natural bough with a static perch, this entity enforces an artificial constraint on a living creature.

A free-flying creature existing outside the confines of the cage. It interacts with the blooming buds and the flowing river. This creature represents the natural state of liberty and serves as a direct contrast to the unnatural confinement of the cage.