In pig country, there is no way to be rid of them. The best you can do is trying to control them to some degree.
Trapping in pens or traps is marginally efficient. Takes up a lot of time for scant results.
Gunning from a helicopter is a lot of fun, but very expensive unless you own one. Poison kills pigs pretty well, but leaves a trail of death behind it. It's also illegal most places without a permit.
I've found constant shooting, year-round, can be beneficial.
On the ranches I had leased we killed 500 to 1,000 + a year on 60,000 acres. 20% on average from helicopter, the rest were shot by myself, ranch hands, my guides and hunters.
Lots were shot just driving around. We had one rule, shoot all boars & sows in the paunch. That way, they died in thick cover, never to be seen again.
There was a trick to the numbers we killed yearly. We had near 100 five gallon buckets filled with soured corn or wheat. We would put a couple of small nail holes in the bottom of each bucket and hang them in trees, all over the ranch, in places where we could shoot from the truck. They dripped enough on to the ground that hogs couldn't resist the smell. Each week, the buckets were refilled with water and a pound of corn was scattered around. Worked like a charm!
One day I pulled up to a bucket and paunched a huge old sow. Piglets scattered in the brush in every direction.
A couple of hours later, I pulled up to a water trap that was well fenced, but one gate was open. I proceeded to melt the barrel on my 22-250 about 50 yards from the open gate. The piglets of the dead sow were all in the water trap. I got 19 of 20, all head shots, of the 15 pound piglets.
I gutted all the pigs and hung them them up on fence posts to drain. Just as I got back to my truck, the 20th piglet came back in the trap and ended up on a fence post with his kin. We threw a big party the next day and dined on those sweet babies.
