What is meant by competitive exclusion is that when individuals of two species' populations share a common resource, they won't be able to use it indefinitely because one of those species' populations will develop an advantage with respect to the other, for example, they will increase their population size, causing the resource to be less accessible to other species' population. This usually leads too to both species developing different strategies to have access to that resource by means of natural selection, as we can see in the picture. Among them, we can see that different species' populations can develop a temporal, spatial, or morphological partitioning, which means that to avoid competition between them, species change their behavior. For example, they can find better to survey for food, or other resources, at different times of the day (one species during daylight, and the other one at night) (temporal partitioning), and they can survey for the same food resource in different places of the same ecosystem and spatial distribution (spatial partitioning), or they can survey for food being developed differently feeding strategies, for example, each species consuming the nectar or consuming the pollen of a flower (morphological partitioning).