When one squawks they all do. The broods of Great Egrets are in batches of three. That makes it loud. The main photograph here was grabbed as the group let out a collective wail.
When they weren’t harmonizing the sibling rivalry came out, big time. And once again they yelled, now at each other.
I have visited this group a few times and noticed even though they can flap around the island trees the same branch is always used as home. That may also explain how Mom knows who to feed when she returns. They have to get confused when they come home and find 50 kids that all look alike.