The Grants witnessed strong selection during droughts in 1977 and 1985. Compare the two droughts. Select all that apply. Select all that apply. In both droughts, large-beaked medium ground finches had the highest survival rates. In both droughts, small-beaked medium ground finches had the highest survival rates. Both droughts resulted in changes to food sources that favored the survival of some medium ground finches over others. Both droughts events provided strong natural selection on medium ground finch populations.