There's a ton of evidence that plants react to environmental stress, disease and trauma in a broadly similar way that animals do. And plenty of species have been shown to communicate with other plants, including (I think - need to check this) not necessarily even other individuals of the same species.
I took hunting to imply a stressful demise for an animal. So, in that regard, I thought hunting would be worse than 'humanely slaughtered' (which for some reason makes me think of respectable alcohol stupors lol) animals.
I think how humane 'humane slaughter' really is depends a great deal on the species in question - it might be a lot different for a cow and a hen, for instance. I guess a bolt through the head is probably going to be pretty quick in and of itself but mammals aren't stupid, they know what's going on and can hear and smell the distress from the other animals around them. Compare that to a rabbit or pheasant or whatever that gets annihilated by some buckshot coming out of nowhere - I know how I'd rather go.
(And yes, there are certainly un-humane slaughter methods too - including, let's face it, kosher and halal slaughter. That said, I'm very suspicious of people who make a big fuss about these methods but aren't vegetarian or vegan themselves; I mean, if you cared that much about animals, you presumably wouldn't be eating them at all.)
Regarding how animals live while they're actually in the wild versus on a farm, well who can say with any certainty? Wild animals certainly suffer from predation by animals other than humans, as well as disease and parasites, cold, hunger and so on - but all these things would be going on whether humans were also hunting them or not. In fact many animals have far lower rates of predation precisely because humans have killed their natural predators, and in some cases it's necessary to keep their numbers down artificially to stop the local ecosystem getting (further) out of balance. In cases like that, it almost seems obscene
not to eat them.