Animal welfare groups voiced outrage today after the restaurant critic AA Gill said he shot a baboon on safari "to get a sense of what it might be like to kill someone".

In a Sunday Times column, Gill recounted in detail how he shot the creature from 250 yards while hunting in "a truck full of guns and other blokes" in Tanzania. He said he felt the urge to be "a recreational primate killer" before shooting the animal through the lung.

"This is morally completely indefensible," said Steve Taylor, a spokesman for the League Against Cruel Sports. "If he wants to know what it like to shoot a human, he should take aim at his own leg. When man interacts with animals he owes a duty of care. If you are killing to eat, that is a different matter. This is killing for fun".

Gill wrote: "I took him just below the armpit. He slumped and slid sideways. I'm told they can be tricky to shoot: they run up trees, hang on for grim life. They die hard, baboons. But not this one. A soft-nosed .357 blew his lungs out."

Claire Bass, wildlife manager at the World Society for the Protection of Animals: "It's hard to say what's sadder – the unnecessary death of a healthy baboon or that he has so little regard for the life of another creature. The vast majority of visitors to the Serengeti have a fantastic time shooting with cameras, not guns. We condemn the killing and the crude portrayal of it as 'entertainment' in Gill's column."

Guy Norton, who studies the behaviour of baboons in Makumi National Park in Tanzania, said baboons are "sentient and feeling animals" and display similar characteristics to humans with strong parental bonds and sociable group behaviour.

"I can understand the repulsion people are feeling because it is hard to see why he would do this in the first place," said Norton. "I can understand it if there was a purpose, but what Gill is talking about is not responsible hunting."

He added that the animal described by Gill sounded like an olive baboon, which is not endangered.

Gill admitted he had no good reason for killing the animal. "I know perfectly well there is absolutely no excuse for this," he wrote. "There is no mitigation. Baboon isn't good to eat, unless you're a leopard. The feeble argument of culling and control is much the same as for foxes: a veil for naughty fun. I wanted to get a sense of what it might be like to kill someone, a stranger. You see it in all those films: guns and bodies, barely a close-up of reflection or doubt. What does it really feel like to shoot someone, or someone's close relative?"

Baboons are seen as a threat by some people in Tanzania because they raid crops, and farmers who need to control their populations can apply for licences to kill them in some areas. They have been classed as vermin in the country and often live on the edges of farming areas.