Immigration or births-which one takes carrying capacity into consideration?

Question

I'm speaking biology-wise ;) Thanks

Answer 1

Actually, births is the one that accounts for carrying capacity.

Carrying capacity is defined as the maximum population (# of individuals) that a particular environment can support.  In general, animals stop reproducing, or at least slow the rate of reproduction, when the population is near this capacity (termed K).  An example of this would be deer, who slow reproduction when food (tree bark) becomes scarce.  There are, however, tons of examples of this in nature: bears and lions (who can be territorial and need a lot of space to hunt/forage); plants that need a particular mineral in the soil; etc. Humans SHOULD fall in this category, but thanks to medicine, we are already way over K.

Immigration can be indiscriminate.  Organisms don't know that they're entering an area that's already at the limit of K when they come in.

Answer 2

That is tricky to answer without context.

From a pure big picture biology, both are involved in carrying capacity to some degree. However, births will happen in many species without regard to carrying capacity. If  births exceeds carrying capacity, survival will be low.

Immigration into a new area with a unique carrying capacity only occurs if the carrying capacity is not exceeded.

So I would have to say carrying capacity is the answer to your question if my assumptions are correct.