I stalked the Mama and Baby to the backyard. She seemed to be teaching him how to sing. I think it is interesting to hear the baby's cries (which draws my attention). Once the Mama spots me, she will signal her mate and I assume she signals the baby to be quiet because he will stop squawking. In this instance, the Mama was at the end of the branch singing and he was behind her, mimicking her. Until they saw me and the Mama flew off.