Density-Dependent Limiting Factor Limiting Factor that Depends on Population Size

Competition Organisms compete with one another for available food, water, space, sunlight etc… Example: Puffins compete for limited nesting sites

Predation Predator-Prey Relationships Regulation of a population by predation. Ex: Sea otters and killer whales regulate each others growth.

Parasitism Organisms that take nourishment at the expense of their host, weakening or killing them

Density-Independent Factor Affect all populations in similar ways, regardless of population size. Usually are: Weather Natural Disasters Seasonal Cycles Human Activities