Here is what I can find. I can find all sorts of laws around not being able to use drones to harass a hunter. Not much on scouting. Here is what I have found:
WI State DNR – Hunting & Fishing Restrictions
Use of Devices
It is illegal to:
Hunt any animal with the aid of any aircraft, including unmanned aircraft and drones;
So a DNR guy could say scouting is aiding a hunter. I can see this argument during hunting season holding up but if not during hunting season I don't think it would. The operator could just say he was photographing ducks which is legal. Or just say e was flying fr fun and nothing duck related.
Also found this.
SECTION 1. 114.04 of the statutes is amended to read:
114.04 Flying and landing, limitations. Subject to s. 175.55, and except as provided in s. ss. 114.045 and 942.10, flight of or in aircraft or spacecraft over the lands and waters of this state is lawful, unless at such a low altitude as to interfere with the then existing use to which the land or water, or the space over the land or water, is put by the owner, or unless so conducted as to be imminently dangerous or damaging to persons or property lawfully on the land or water beneath. The landing of an aircraft or spacecraft on the lands or waters of another, without the person’s consent, is unlawful, except in the case of a forced landing. For damages caused by a forced landing, however, the owner or lessee of the aircraft or spacecraft or the aeronaut or astronaut shall be liable, as provided in s. 114.05.
So it appears you can legally fly over private property if I read this correctly.
As all things, vagueness tends to rule here.
Mark