Several types of birds appear repeatedly in The Awakening. We’ll break it down for you.
At the start of the book, the parrot shrieks and swears at Mr. Pontellier. Now, we’ll take a wild guess and say that the parrot represents Edna – or, more specifically, that it gives voice to Edna’s unspoken feelings. Also, it’s in a cage, which is a form of literal imprisonment that highlights Edna’s figurative imprisonment.
The mockingbird, also caged, likely represents Mademoiselle Reisz with its odd markings and the whistling notes it produces. Moreover, we learn at the start of the novel that the mockingbird is perhaps the only one who’s capable of understanding the parrot’s Spanish. It’s a stretch, but by the end of the novel, Mademoiselle Reisz is the only one capable of understanding Edna.
Caged birds in general are representative of women during the Victorian Era, who expected by society to have no other role besides that of wife and mother. It’s reasonable to think of the women as living out their lives in gilded cages – present for decoration, given every comfort, and banned from any real freedom.
She says to Edna that "the bird that would soar above the level plain of tradition and prejudice must have strong wings." In other words, you need courage to defy society.
As Edna is about to walk into the ocean, she sees "a bird with a broken wing . . . beating the air above, reeling, fluttering, circling, disabled, down, down to the water." This bird could represent Edna’s failure to find freedom – her failure to "soar above the plain of tradition." The bird has a broken wing, yet Mademoiselle Reisz said it would need to have strong wings. Similarly, Edna clearly lacks those strong wings as she drowns in the sea.
Another interpretation is that Edna’s plunge into the water is a defiant rejection of Victorian womanhood and that the bird represents the destruction of that irksome ideal.