Cyn, they typically fledge between 17-19 days old. During fledgling, the parents will be singing and calling them to encourage them to exit. They may also have food and briefly land at the hole and fly off with the food.

You will know they fledged if you watch the box for some amount of time and don't see the parents visit. In my case, they were chit chattering to get me away from nearby trees. It was loud and they'd perch close to me. This gave me the signal that they likely went. I peeked into the box. If they're there, they will sense you and you will hear them hunker down inside the box. If they've fledged, you'll likely not hear anything, and the bluebirds won't land nearby and chatter at you or dive at you. I was only dived at once after fledging while at the box.

For me here in N.E. Ohio, my blues typically fledge on day 19. Rarely have they fledged earlier than this. This year was the 2nd year I could recall having bluebirds fledge in July on day 19. My first successful nest ever fledged in June on day 17. Don't think I've had them fledge sooner than this, and that was my 2nd season. This is my 6th year with the bluebirds.

~Tim~

Like Tim, I go over to the box and wait for a reaction. I walk up to the box, and if the timing is right (past the day when they should have fledged) and nobody scolds me for being near the box, then they have probably fledged.

Thanx for the info! They all looked great today. I've got day #17 marked on my calendar but unfortunately I'll be gone most of that day. Do they normally fledge at a certain time of day?

Mine have fledged in the morning and in the evening. I guess they go when they're ready.