Monitoring Nest Boxes

Being a conscientious Bluebird landlord involves more than simply buying or making a nestbox and mounting in a good location. Monitoring your nestbox means that you open the nestbox on a regular basis to inspect the box and its contents.  In doing so, you can determine the type of bird occupying the nestbox based on nesting materials (See Nest Identification under the Resources Tab).  You can take note of the number of eggs and/or young that have hatched.  You can also identify the relative age of the young by knowing when the eggs were laid and hatched. (See Eastern Bluebird Nestling Growth Chart under the Resources Tab).

Photo by Mike DeBruhl

Nestboxes should be monitored at least once a week for pests and predators. (See Pests and Predators under the Bluebird Facts Tab) Bluebirds readily tolerate humans monitoring their nestboxes. They will not abandon their young because humans have looked at or touched them. Bluebirds do not have a good sense of smell, so your scent on their nest will not disturb them.

Care should always be taken when opening a nestbox, especially once the hatchlings are 12 days old, as this could cause them to fledge too early. The nestbox should be cleaned out after each brood of babies has fledged. Bluebirds will not reuse a nest. If the old nest is not cleaned out, they will build a new nest on top of the old one which places the new nestlings dangerously close to the entrance hole.

Bluebirds will typically produce two or three broods from March to August in South Carolina. A typical brood is 3-5 eggs.

If you want to formally monitor your box, which is STRICTLY OPTIONAL, download the Trail Monitoring Form (under Resources Tab) and record your observations weekly starting with the nest building activity.  When fledging occurs, you can go to Resources/Trail Reporting Form found under the Resources Tab.  Follow the instructions, fill in the required data, and press the Submit button. The data is collated by SCBS and posted on this web site under Resources/Trail Statistics.

The data gathered from trail monitoring is also sent to Cornell Lab of Ornithology.  This data allows organizations such as NABS to identify problems within the Bluebird population and to react in a timely fashion.