**Density-dependent limiting factors** are population regulating factors that affect the size of the population of the organisms **in response to their density**

There are several density-dependent limiting factors that affect the size of the population, these include *competition, predation, herbivory, symbiotic relationships such as parasitism, disease*, and *stress from overcrowding* in the area.

**Population size** is the term to describe the number of organisms present in a population. It is directly connected and associated with the amount of genetic drift and other population bottleneck factors.

**Competition** is an ecological interaction between species in which they compete or strive for similar resources in an ecosystem. One or both species can be harmed.

Hence, if there is an increase in the population size there is a possibility that there will also be an increase in the competition within the species.

For this scenario, the lynx population and the hare population share a predator-prey relationship. Therefore, the growth of the population of hares is kept in check by the lynx population.

Therefore, if the lynx population suddenly disappears, there would be less pressure on the hare population. Thus, the hare population would most likely **increase** at a more rapid rate.

The rapid growth of the hare population can affect the food chain of the ecosystem. For instance, a large hare population would be likely to reduce the population of plants on which it eats.

When there are limited resources, logistic growth will occur. This means that the growth rate decreases once the population reaches its maximum capacity. For an instance, a small grass field is limited only for feeding ten cows. If the population of the cow grows higher than what the field can accommodate, there will be a competition for food. Only the cows which are properly fed will survive, and those cows which are not fed with grass will eventually get sick and die. As a result, the growth rate of the cows will decrease.

A density-independent limiting factor includes natural disaster such as earthquakes. The effect of an earthquake has changed the human population in the affected area. For example, the earthquake which happened in San Francisco during 1906 was considered as one of the deadliest earthquakes in the US history. According to the records, an estimated 3,000 people died during this event. As a result, the mortality rate during that year in San Francisco has increased due to the deaths of these people. Also, due to the damaged houses and structures during the earthquake, some people were forced to relocate into different states which affected the migration rate of the affected area.