Well that explains Beatrix's shift in perch to the camera box. She did the same last year when the chicks started moving to the nest box edge and doing a lot of flapping.
Yesterday, about 5:45 pm, Beatrix was on her new perch when she took off like a shot with a lot of yelling. She meets up with Ty and does a food exchange with him, then rushes back to deliver the food to her chicks. Ty circled once and landed on the other corner. She didn't stay with the chicks very long and was back on her perch.