This is probably way more efficient than just going out stalking but with something like 3 million feral pigs in the USA it is going to take a lot of effort to

This is probably way more efficient than just going out stalking but with something like 3 million feral pigs in the USA it is going to take a lot of effort to bring the problem under control. Perhaps something like the Judas Goat, http://en.wikipedia.org/wiki/Judas_goat http://en.wikipedia.org/wiki/Judas_goat with an infra-red strobe (so you don't end up shooting it) might be more (cost) effective.