8. Animals will self-regulate their populations in times of shortage
Just as human foragers did - by limiting sexual contact, spontaneous or induced abortion, and infanticide. To this, modern humans will add state regulation of fertility a la China. But all of it is in response to carrying capacity problems, not a preventive measure.
What's interesting is that birth rates are declining so dramatically world-wide, in times of remarkable plenty. My take on this is that the underlying "evolutionary system" (I haven't figured out what to call it yet) doesn't require so many people, since our technology is so much better at maximizing entropy that human beings are. The most important role of human beings has become the production and control of energy-conversion technology, so the evolutionary (?) system doesn't need as many of us it once did.