The number of black hawks has ________ because the encroachments of humans on their territory have caused them to shun their customary breeding places.
句意： 黑鹰的数量已经在减少， 因为人类侵占了他们的栖息地， 使得他们逃离了自己习惯的繁殖地。 dwindle减少。 extrapolate推断。 increase增加。multiply繁殖。 因此， 本题的正确答案是A。