the change in squirrels' population over time needs to be shown in a graph
neotropical_pygmy_squirrel is squirrel. red_bellied_squirrel is squirrel. african_pygmy_squirrel is squirrel. squirrels is mammals. tree_squirrel is squirrel. squirrels is animals. red_bellied_squirrel is mammal. tree_squirrels has adapted_to_urban_areas in_north_america_deer_populations has ballooned