We've been educating and cracking down for decades. I'm not suggesting an alternative, rather an additional tool. I think a bomb might be quite educational. I would be happy with peaceful monitor drones, thermal imaging cctv, a DARPA challenge for autonomous vehicles to fly over reserves and locate poachers, maybe tag them, or dart them, then alert authorities, but that has far less chance of happening than military training exercises with an added benefit.

Edit: I have more to say.

AI monitoring is needed because the areas are too large for people to watch. Is a geostationary satellite able to scan a large reserve for people, or are numerous cameras closer to ground level needed? Securing the reserve boundaries - how far away are we from forcefields? Towers with some sort of array of detectors monitoring the boundaries, broken beams? Radar? Lidar? Seismometers? Pressure sensors? Money often talks louder than education, as does short-term mindedness over long-term. Education hasn't stopped murder, burglary, mugging, rape, ... if it does stop poaching, it won't be any time soon. This sounds like the opportunity for challenges which techies like to solve. My knowledge of technology is unfortunately too broad and superficial, as you've probably gathered, but someone's surely got to be tempted.