We mounted the webcam just over a nest and filmed by motion sensing or timelapse nearly every day. The last baby flew out of the nest yesterday. Here's an almost-daily view for three weeks (click to enlarge):
Time-lapse: warming eggs, leaving for food, warming eggs, leaving for food, all day:
A kymograph below reveals the on/off the nest pattern throughout the day. We found info online stating that the mother rarely leaves for more than 5-10 minutes, but we plainly caught her taking a 20-minute lunch at 11:40-12:00 in the kymograph...