If the hawk population decreases due to overwhelming, what would be the effect on the food chain

Overpopulation in the area's main source of prey, such as rabbits, mice, etc.

Explanation:

A hawk is a predatory creature. That means that it feeds off of prey, such as mice or rabbits. In the case that the population saw a sudden decrease, the population sizes of the hawk's main source of prey would increase due to hving less of a threat towards their own survival.