RE: Trail cameras to catch poachers?
Infrared cameras would work but I would put them where they aren't going to be hanging around or walking around (like just somewhere on the road entering the property). Sure you might not catch them in the ACT of shooting but a call from a warden would keep them off of there in the future.
Also, a good board full of nails buried in the dirt where they drive will get them (make sure landlord, other people who frequent the property know this). Also, a simple "traps" sign might keep them out.