Okay, I gotta say here that "bats wake up" is a bit of a mystery to me. I have been in hundreds of tropical bat caves and at any point, with lights out and even before they know I'm nearby, they always seem to be awake. Cave bat colonies are never quiet and sometime really quite loud. You can turn your light off and sneak up on them from a long ways off with a dim red light and still hear them making a racket three turns of the cave passage before you get there. Makes me wonder if the bats ever actually sleep.
Okay, back to the cave. Earlier, we had seen a black hawk sitting on a downed tree with bats flying by trying to score a late evening snack. I never got a photo of it going after a bat but it clearly wanted one.