Interesting it has come to this... feral pigs are an ecological problem. Their 'rooting' behaviour damages tree roots. In fact, early settlers in New England knew that the way to clear land for agriculture was to pen their swine in amongst the trees to be removed. They would die off quickly, and the standing timber could simply be pulled down by an ox team. Sure a time-saver if you think about how long it took to fell trees with an axe, especially before the advent of quality steel that would actually hold an edge!
Anyway, there's my ecology lesson for the morning. I'ma get off my stump now!