Those damn hogs destroyed couple of my seedlings last year. And you can recognize it was them because of the mess they leave behind.
I was thinking to put pots inside some spiky bushes because then they will be out of reach. Pots should be worked inside the bush. Or maybe put them in some hardly accessible rocks or something. Another option is chicken wire around plants... I believe each of us has his own problems due to unique situations.
I want to add some site details:
Access point are crucial so you should be careful not to leave a path that leads to your site. That is common reason why people get busted or ripped along with the inability to keep their mouth shut.
I walk over rocks (they dont leave any trail and my terrain allows me that) and when I am far enough I walk freely. Some people carry a plank and then find a bush as access point, put plank over the bush, walk over, and then remove the plank and bring the bush in its original state.
You can take many acces points, even slightly fertilize the path you create so it regrows back again. Best time for visiting your site is early in the morning or at night if conditions allow (help of the moonlight). Monday to friday is always better option than weekends.
You could opt for getaway route from the site in case of emergency. One more thing: good logic for sites is that they are the places that are counter intuitive for people to go to. Meaning that maybe your site is just behind that nasty looking bramble or rocks.
Be sure to get in shape so you dont end up tired in the half of operation. Always drink water and wear clothes that are comfortable and light but also colored properly so you 'blend' in the surrounding. It is a good thing if you can invest in good boots that will ensure optimal walking and protection from snake bites although if you dont mess with snakes they will mind their own bussiness.