Human birth rates are falling at a rate that has some fearing population collapse, but could this a natural biological repose to threats of overpopulation, rather than any cause for alarm?
This raises the question as to what controls population in other species and, why is overpopulation rare? Would all species not population controlled by predators just multiply like bacteria in petri until dish resources are all consumed, or does nature, and even potentially humans, have other mechanisms to constrain population at a more optimum level? In practice, resource constraint and predation alone as population control would for many species would result in repeated huge population swings, so logically, there must be more.
Analysing population mechanisms in other species may provide some interesting insights and possible answers to at least a large part of what is happing with birth-rates that will determine whether our future is population is one of: continued growth, collapse, or stability, on a planet where population of all life is not growing.