The little maw peeping from behind the older bird seems very insistent indeed!
I have heard that when the baby birds present their open mouths to the parents, the adults have no choice but to feed them. It's an involuntary response. I've also seen video of adults with fledglings on together on the ground. The parents kept turning away from the young birds, trying to hang onto their own lunches. The whole paradigm strikes me as very telling about the challenges of parenthood. ;^D
