Several Ecology Students Were Tracking the Population Ranges of Two

Multiple Choice

Several ecology students were tracking the population ranges of two species of squirrels that live in the Cascade Range of Oregon. These students noted that when both species of squirrels were present in a region, species A could be found from sea level to about 900 feet above sea level, and species B could be found from about 900 feet to 1,500 feet above sea level. However, when species B was found alone, it had a range of about 500 feet to 1,500 feet above sea level. This is an example of:

A) competitive exclusion.
B) parasitism.
C) predator avoidance.
D) coevolution.
E) habitat fragmentation.