Mr Short's wife, Leanne, said she knew where her husband had gone on Sunday when he did not return after going to buy milk.
Police in the Taupo district have been informed of Mr Short's vigil, but have been told by the district's mayor, Rick Cooper, not to take any action.
Mr Cooper said: "He's very frustrated, he's making a stand ... There's no issue for the police, there are no laws being broken, he's not reported missing.
"Chris is a decent, upstanding person, he's just very passionately against 1080. He's been in the bush all his life."
An experienced bushman and hunter, Mr Short is understood to have only a few items and a few days' food with him but is refusing a tent, sleeping bag and any other supplies.
Friend and hunting partner Martin Ellis went up to check on Mr Short on Monday and said his friend was wearing a protective helicopter suit.
He said Mr Short was in good spirits.
Mrs Short said last night that she and the couple's 20-year-old daughter would go to the mountain today to be with him.
She said it was unfair to criticise her husband's protest as being selfish.
"When he's lying awake hearing animals screaming - dying - outside, it rips him apart. This is something that Chris has always been passionate about and this is his way of making a difference."
Mrs Short said her husband was in good spirits being on the mountain and that his protest was also a personal healing experience.
"You think to yourself, if you had two weeks to live - you'd have a bucket list of things to do. For Chris, this has been something he has been doing for years. And if dies trying to make a difference, he'll be happy."