Answer:
I am explain you in image
The replacement rate is the level at which a population remains stable.
<span>Replacement rate (level) is the fertility rate and represents the average number of children born per woman at which a population<span> exactly replaces itself from one generation to the next (without migration). More precisely, </span>it is the amount of fertility needed to keep the population the same, from generation to generation. As a result of the total <span>fertility rate,</span><span> there will be no increasing or decreasing of the population, it will be stable. </span></span>
The Circuit-Level involves the spinal cord.
Herons are very large birds, and due to their intimidating size, they have very little predators. They have a varied diet and consume many different prey (fish, snakes, amphibians, and probably many other small animals). If the population of herons would decrease, the population of the other organisms living in the same environment would increase since they would have a greater chance at survival (since they are not being eaten by the herons)