What primary food source dictates the timing and severity of the hawk's seasonal migratory behavior?

Answer

Small rodents, particularly voles and lemmings

The movement is strongly linked to the availability of their primary prey—small rodents like voles and lemmings—which fluctuate drastically based on the Arctic season.

What primary food source dictates the timing and severity of the hawk's seasonal migratory behavior?
locationbirddistributionhawk