The poem
Still dark. The unknown bird sits on his usual branch. The little dog next door barks in his sleep inquiringly, just once. Perhaps in his sleep, too, the bird inquires once or twice, quavering. Questions--if that is what they are-- answered directly, simply, by day itself.
Enormous morning, ponderous, meticulous; gray light streaking each bare branch, each single twig, along one side, making another tree, of glassy veins... The bird still sits there. Now he seems to yawn.
The little black dog runs in his yard. His owner's voice arises, stern, "You ought to be ashamed!" What has he done? He bounces cheerfully up and down; he rushes in circles in the fallen leaves.
Obviously, he has no sense of shame. He and the bird know everything is answered, all taken care of, no need to ask again. --Yesterday brought to today so lightly! (A yesterday I find almost impossible to lift.)

This poem is reflecting our blindness to the world. I believe that it shows how if we stopped to just take things in, like the bird or the dog, we could have a much greater outlook on life than we do.
I think this poem is about a bird and a dog.
I Agree
Amanda, I believe you are right. I just annotated this poem for my AP Literature class and that is the feeling I got.
Personification is used in the animals to give the reader a Naturalist perspective of perfection and how humans are both arrogant and ignorant in this world.
Difference In Opinion
I feel as though the poem is actually about innocence, as well as, ignorance and not about blindness in the world. The reason the dog is not ashamed of what he has done is that he is not conscience of the fact that he has done something wrong. Both the bird and dog inquire about something so simplistic that their questions can be answered through day itself. In the last stanza the bird and dog, like ignorant children, innocently accept their condition and are secure in feeling that everything will be taken care of.