This Summer,you Are Returning to the Research Station in Costa

Multiple Choice

This summer,you are returning to the research station in Costa Rica to follow up on the population of butterflies you have been studying.You are disappointed to find that there are fewer this year than last.In fact,at dinner your friends studying frogs and birds are complaining about the same thing.What type of influence do you suspect?

A) a density-independent effect like an introduced predator
B) a density-dependent effect like environmental disruption
C) a density-independent effect like environmental disruption
D) a density-dependent effect like an introduced predator