There is a population of deer in a forest. They eat shrubs and low tree leaves. At first, while the population of deer is at its minimum, there is no problem finding enough vegetation to sustain them. But as the population rapidly increases, food, shelter, water, and other resources are hard to find. This creates density-dependent, competition, and the deer population levels off because of carrying capacity which is the maximum number of deer that an environment can support. If the environment cannot support anymore deer, they start to die off and that's why the graph levels off.
As you can see, this is an example of density-dependence because it is predation.The coyote is the predator and the deer is the prey. This is what could factor into why they start to level off and not increase anymore in population because they are being hunted. The death of the deer also affects the population and its carrying capacity.
As you can see from the photo above, the forest is in a drought which is an example of density-independence. Without leaves and shrubs and grass to feed on, the population of deer will start to level off or even decrease. But in a logistic graph, the deer population will level off.
- Immigration affects the population immensely because when more deer come into an environment, it raises the supply and demand for food, shelter, and water. If you look at the graph above, the rapid rise in population can be due to immigration.
-Emigration also affects a population immensely. When deer leave an environment, it can decrease the number of deer in the population. If you look at the graph above, the leveling off in the line of the graph shows how carrying capacity can affect a community. Emigration can be one of those factors.
Births affects the population tremendously. Just like the baby boom, when deer have a lot of offspring, it can raise the population. If you look at the graph above, the rapid rising in the graph could be because of the birth rate of deer
Death also affects the population. If you have a lot of deer dying, your population rate will level off or decrease. The graph above shows also how death can be a factor of the leveling off with carrying capacity.
Limited resources can cause the population to rise along the S-shaped curve of logistic growth. If there isn't enough resources like food, water, and shelter, for everyone, then density dependence of competition will start. For example, if two deer are starving and there is a piece of food in front of both of them, they will fight until one gives up or dies. This is called competition and what can happen when there are limited resources.