On the 21st day the mother's behavior changed dramatically. She would sit on this branch near the chicks and "yell" at them constantly, and she would show them her feathers in this "field marks" display. She would also land on the nest and before feeding them would poke at the chicks quite briskly trying to literally push them out of the nest, alternating with pulling feathers out of the chicks (ouch!).
Anna's Hummingbirds, Copyright 2010 Gary Yost
From Anna's Hummingbirds, Folio Set of 20