Red squirrels usually eat hazelnuts, but due to a reduction in their food source, they had to share resources with gray squirrels. The number of red squirrels decreased over time, and gray squirrels gradually replaced the red squirrels because they are better adapted to the environment. This is an example of
competitive exclusion. Competitive exclusion occurs when different species compete for the same resources in an ecosystem, leading to one species outcompeting and eventually displacing the other. In this case, the gray squirrels were better able to adapt to the changing food availability and outcompeted the red squirrels for resources, leading to a decrease in the red squirrel population.
