If you want an enhanced bird experience, consider placing a Blink camera in your birdhouse(s). The Blink camera is an outdoor security camera,  available from Amazon, which works perfectly with the docking system included in each birdhouse. The camera system comes with a sync module which is placed inside your home and connects to your Wi-Fi. It then bluetooths out to the camera which is powered by the 2 included lithium batteries.

If you know you will be putting cameras in multiple birdhouses, you can order the sync module with several cameras or you can add additional cameras at a later date. There is a subscription available which provides instant viewability of the video clips for $30/year per camera through Amazon.