Sorry, these are considered a significant pest in New Zealand, they have no natural predators. Same for rabbits, feral goats, possums, and deer (yes deer are listed as a pest. Heck even Chamois and the endangered Himalayan Thar are pests here (non native, no natural predators).
The farmer is happy for me to get as many as I can, they NEVER go away, there's too many. If they get out of control poisons like 1080 are used (look up the effects of 1080 on mammals, it's not nice), so my method is far more humane.
And usually I do take them for meat, but I have plenty at the moment.