wrote

Not a bad guess. We have at least a dozen snakes that can climb trees
and will take a baby squirrel.
The snake was probably sitting in the nest digesting the one that
didn't get out.

I'd say there was something up there that made them either jump or stay, and
as so many of them jumped, it must have been some sort of predator. Small
owl. Snake. Do skunks climb that high?

Steve