WHEN Bruce Parry was 13 he took himself off with the family labrador, Polly, for a week, sleeping in hedges in the Lake District. He filled his rucksack with dog food “so it made walking difficult”, but he thoroughly enjoyed himself. He claims that at school he used to shoot and trap small animals such as hedgehogs, squirrels and pigeons, then cook them on a Belling stove and eat them. Hedgehogs taste like smoked chicken or pork, he says, and squirrels are chewy.

Parry has gone on to taste a lot of nasty things, such as cow’s blood “which congeals, and has stringy things going down your throat and it’s warm and frothy and salty”. He has also eaten a cakey thing with, among other ingredients, rats. I’m glad we are having coffee and not lunch — there’s more where this came from.

To prepare himself for a new television series, the explorer trained his gut to cope with polluted water and jungle delicacies such as frogs, beetles and locusts by existing for weeks on mouldy food at his home in Wales. Green toast built up his immune system. Incidentally, some beetles anaesthetise your mouth

and make it go numb for 24 hours, so be warned. “I probably would not have eaten human flesh, but with live beetles and animal flesh, you just put it in your mouth and get on with it,” he says.

Interviewing an intrepid explorer in the heart of London is full of surprises. First he apologises for wearing a dinner suit at 11am: this is because he is staying with a friend, but when he arrived at the house from an all-night party the friend had gone out for breakfast and he could not get in to change. It might have been different if he were still sporting the bone that was hammered into his nose in West Papua. That might have turned heads even in London.

I am suffering something of a day after the night before myself, and his tales are doing my stomach no good. The Kombai tribe, with whom he shared local customs — his mission is to find out how the other half lives — paint their faces with chalk and berries mixed with soot, and the men put things that look like cocktail sticks through their noses. Parry, ever the searcher after the authentic experience, succumbs to having this excruciatingly painful adornment, a thorn from a sago tree, pounded through the bit of the nose, the septum, that cocaine addicts tend to lose. His description of the ringing in his brain as the thorn is knocked in and the fact that the thorn hurts again each time he wipes his nose makes my eyes water.

All that is as nothing, though, to his most painful experience to date: having his penis pushed back inside him. “I’m not sure why they do it, unless it is to get the penis out of the way when they are running through the jungle or because it is more hygienic when they are sitting on the floor and there are thousands of ants about. Although that doesn’t make a lot of sense as their testes are still dangling. Anyway, I fainted when they tried to do it to me. It was a very odd sensation; I had to lie down with my feet in the air, which looked rather odd as I was naked.”

Parry is a light but fastidious traveller. He carries a rucksack in which everything — hammock, tiny wash kit — has its place. It has a hidden pocket for his trusty parang, a machete-like knife he had made.

His scariest experience was in Gabon, where he was initiated into the Bwiti religion with a rebirthing process that involved consuming a large quantity of a hallucinogenic root: “It was an intensely personal experience that makes you face your inner demons.” Before the demons appear, the ritual begins by making the imbiber vomit violently — all nicely captured on film.

Parry has also slept next to a cannibal who admitted killing three men and eating two of them (all witches from another clan, so that’s all right). Parry says that the tribe’s way of dealing with evil people means that everyone behaves themselves because they do not want to be accused of being witches.

According to Parry, this is what they do to witches in the storyteller’s neck of the woods: “They chop off the limbs, place them outside the village, then devour the stomach and brain because that is where the soul is, and devouring the soul is the only way to put an end to evil witchcraft.

“The man who told me this was a wonderful father. That is one of the most important lessons I have learnt from these tribes: they have nothing, but they have plenty of time to look after their children.”

• Tribe, BBC Two, Monday at 9pm