I've found that Whitetails often hang out near Grouse (Ditch Chickens) in Maine. As MC said, the forest has it's tells and a flushing bird is a strong warning for a nearby deer. Perhaps you can spot them (the birds obviously) in softwood trees I sure as he!! can't!
Ducks? a little different and not much experience to offer there other than if seasons correspond I would back off that area but the deer are probably used to the shotguns that time of year anyway.
REM7600