After observing this bluebird family for the past month, I was determined to at least try to see these nestlings off on their fledging day. If you've ever tried to do this you know that even with dedicated vigilance, this takes a good measure of luck.
Besides being home at the right time and counting the days from hatching (14-18 days to fledging), there are some behaviors that you can watch for that indicate fledging is near. Bluebird family members use a one note contact call to help locate each other. Several days before fledging, the nestlings and family members begin to sound these calls with greater frequency. It becomes very apparent when these calls come from the nestlings in the nestbox. Additionally, as fledging time approaches family members wait for longer intervals between feedings, the juveniles taking their cue from the parents. In this case, the male parent and juveniles visibly perched for longer periods and guarded the nest area and near by trees with greater vigilance and aggression.
It was not uncommon to see the whole family advance to drive away a poor woodpecker who happened to land on their oak tree. This tree is the preferred guard perch and preening area for family members with direct view of the nest and feeding area. It is also the tree that stands the right distance away and in front of the nest box with branches easy to reach and safe for a fledgling's first landing.
The two videos below represent day one and day two of fledging. In the first video, a male is the first nestling to venture out of the nestbox. The video was taken at 7:30 pm and an hour later, near dusk, I witnessed two male nestlings fledge and land in the limbs of the oak.
In the second video you will see the last nestling leave the box the next morning, a pretty female. She is sounding the contact call as she looks at her new surroundings. If you listen carefully, you can also hear the male chipping in the background.
Next post: More fun juvenile behavior as family members feed nestlings a day before fledging.
To see a determined juvenile trying to feed the nestlings for the first time, visit: Bluebirds Adapt to Single Parenting. And to see last season's juveniles bathing and feeding siblings visit: Juvenile Bluebirds Enjoy the Water and Juveniles Helping Parents. To see all my bluebird posts visit: Bluebird Family.