Select all the correct answers. Red squirrels and gray squirrels have been the native species on an island for many years. A few years ago, black squirrels entered this island. The black squirrel is an invasive species. Invasive species aren’t native to the ecosystem. They move into an ecosystem because of natural changes or human intervention. Red squirrels and black squirrels have identical food requirements, but gray squirrels have a different diet. What three effects will these events have on the island’s squirrel population?
A The food availability of red squirrels may increase.
B The red and black squirrels will have to compete for nutrition.
C The food availability for gray squirrels will not be affected.
D The food availability for red squirrels may decrease.
E The food availability for gray squirrels will be affected.