Female Eastern Bluebird on nest box preparing to feed baby inside

We just put up this nest box in April. I took this photo early in the morning of July 22, 2015, the day the four babies fledged. I did not observe them fledging, but by evening the nest was empty. More information at http://barnswallowfriends.blogspot.com/2015/07/nesting-bluebirds-bugs-for-babies.html