Answer:
... removing fruit in the environment?
Step-by-step explanation:
So, generally when talking about birds with different beaks, you're talking about Darwin's theory of evolution. Now, in his experiment, he observed what happened when different food sources were added or removed, and the result was evolution. The answer of the question would most likely be evolution, because of "survival of the fittest", but the question you are answering is most likely "What is the effect of removing fruit in the environment?"