What is an example of a density-dependent factor affecting population growth?

The availability of food resources as population density increases is a prime example of a density-dependent factor because it directly relates to how the population's growth is affected by its size. As the population density rises, the competition for limited food resources intensifies. When more individuals are competing for the same amount of food, it can lead to insufficient nutrition for some, ultimately affecting survival and reproduction rates. In contrast, other factors such as natural disasters or seasonal climate changes are considered density-independent factors because they impact populations regardless of their density. These factors can cause widespread effects without being influenced by how crowded a population is. Migration patterns also do not typically depend on density but may be influenced by external factors like environmental changes. Thus, food resource availability is intricately linked to population density, making it a quintessential density-dependent factor.