A squirrel population in a forest will only be as big as the available food source allows, and probably a little smaller after you account for predators, disease, etc. What is the name of the tendency of a species to multiply until it reaches terminal population?
Sort of like how when you drop a tennis ball from a building, gravity will only accelerate its fall so much until wind resistance counteracts it. This results in the ball reaching a constant velocity, known as “terminal velocity” in physics.
Similar to the phrase “evolutionary niche”, but not really involved with evolution.