Small, maybe 5 inches from tip of beak to tip of tail.
Too fast to see colors of this bird, but, the tail looks like a two pronged fork. Has built two nests in the supports of my metal awning above my door. Nests have a base that looks like a mud boar bee nest. They seem to be a friendly pair, nesting together, flying together etc. They are in the nests at night, highly visible to us.
Comment Could you send us a photo of the nest? That would help identify bird. Susan