Well, considering if the deer and the hawk have a direct predator prey relationship, where the deer are the prey, then the hawk population will also drop quite a lot, unless they have some other major food sources, but chances are they'll still drop.
If it's NOT a direct predator prey situation, for example: The deer happen to eat something that the hawks also eat, or the deer are prey for something the hawks eat: If the deer eat something the hawks eat, by them dropping it means there will be more food supply for the hawks, meaning as the deer population drops, the hawk population will go up.
If the deer are PREY to something the hawk eats, then by there being less deer, then whatever the primary consumer of the deer is will also drop. If the hawk eats that predator, then there will be less of those predators, and less prey, meaning the hawk population will still drop
You were most likely given a food web to look at. Seeing how you didn't post that, I just gave you the only 3 situations that could happen.
Genetic drift is an evolutionary force that requires the presence of a small population. It is a random process that fixes one or other alleles randomly in the gene pool of a population. Genetic drift does not take account of survival fitness imparted by alleles to the individuals. Since random and chance events such as the death of all the individuals having a certain allele in a population affect the small population more intensely, genetic drift works on small populations only.
