More Bluebirds!!!!

Another set of bluebirds has moved in! I did not clean out the bluebird house and have not seen these new birds clean it out, but they are definitely bringing in new straw for their nest. They are just so cute to watch! Both the mama and papa have been busy. They begin at daybreak and work all day. I was sitting on the porch yesterday watching them for quite a while. One time the papa and mama flew in together to the house, chattering noisily to each other. Mama went into the house and stayed a few minutes while papa sat in a  nearby pine tree and watched. Then after she left, he flew down, poked his head in and then flew off. Maybe he was checking out the nest to see if she did it correctly. :) He did that twice. I need to find the time to read up on bluebirds. They are just the cutest birds to watch! Maybe this time I'll get to see the babies fly. I wonder how long it takes them to get the nest ready? Does anyone know?