RE: Follow the crows???
1st - just because you have a feeder does not mean your gonna see deer.Depending on where you set it up the deer might go totally nocternal.
As far as crows giving away a deer.I always pay close attention to crows early in the morning when deer will pass thru where crows come off roosting areas.I have spotted deer in woods where crows have been squaking.
Same holds true for barking tree rats,dove or Quail.Watch,listen and pay attention to nature will often give up other game animals.