Lots of times,birdhunting,there are a lot of folks afield.Some in camo.
In PA, a good part of Upland season runs concurrently with deer/archery season. You are exactly correct about hunters in camo being in the woods or at the field edges. Every year, at least once, my dog finds an archer while quartering for birds. They are both surprised; though, I suppose they can hear her coming with her collar beeping.