Which predator do whitetail deer fear the most?

I suspect this reaction depends a lot on the area and the past hunting pressure. Yes, man is the most lethal predator on the planet, but different experiences can mean different reactions in prey species.
When Dad & I were living in Kentucky, we had a literal herd – often up to 21 deer – that moved back and forth across the properties, inside the city limits, and often stayed and grazed right outside the back door. Dad could sit on the back porch and the newer fawns would often play around within feet of him, only being warned by their does if they got to close for their liking, and Dad quite often talked to them, giving them ‘lectures’ about the coyotes we had pass by from time to time. Sometimes they actually seemed to pay attention to him.