There is a classical set of mathematics equations called The Lotka–Volterra equations, or Predator-Prey, or Wolves and Rabbits equations that describes the population of two species that interact in nature. Example as the population of rabbits increases, the number of wolves increases as well until the wolves start eating all the rabbits and the wolves begin to starve and die off. Then the rabbit population increases again.
Is it possible a predator to Monarchs, a type of bird for example was starved out during the lean years allowing the Monarchs to recover?.
True story. A few years ago I volunteered to hatch Admiral butterflies in a fish tank on my screened-in porch. It was so much fun. The neighbors grand kids would come over to watch the caterpillars grow and form cocoons. Finally the butterflies started to come out. We had about a dozen It was spectacular. The kids had them on their faces and fingers. We took lots of pictures.
I had one of the kids open the porch door and take a butterfly outside to let it go. With a little prodding the butterfly walked onto his finger and they stepped outside. He tentatively waved his hand slowly and eventually the butterfly took off and fluttered into the air just about at eye level. Then, Baam! a bird swooped down and grabbed it. Poof! We were all horrified. The kid was screaming, then crying. His brother started crying in sympathy. His grandmother was upset. Ugh!
I hope he doesn’t turn out to be some mass murderer as a result of that trauma.