Seasoned adventurer Bear Grylls says his years surviving some of Mother Nature's toughest challenges has taught him of the world's unpredictability and experiencing the Christchurch earthquake just reinforces this.

Grylls, who's Man Vs Wild TV show sees him dumped in some of the most remote parts of the world with only his survival skills to rely on, was filming an episode of the show about 250km outside of Christchurch when Tuesday's quake hit, but didn't initially realise its extent.

"I was on a traverse - a big river with a wire across it - and the whole thing was wobbling. I got to the other side and the crew said the whole ground was shaking."

It wasn't until they finished filming the next day that they heard what had happened.

"If I have learnt anything over these years is you can't take the wild for granted and it's that unpredictability that's the magic. But sometimes it turns nasty and things happen. Our job is to look after each other and take care of each other."

He says he has no doubt New Zealanders can come through the tragedy stronger than before.

"If any nation on earth can cope with it, you guys have the spirit.

"You're renowned around the world for your tough resilience - it's what makes you so darn good at rugby - but it's that same spirit that will get you through this."

Grylls has spent a few weeks in New Zealand filming two episodes for the latest season of the show.

He says he was shocked at how wild some parts of the country were.

"One of the privileges is showing people just what a wilderness New Zealand is.

"I always considered New Zealand as the playground of the world and it would have been crazy to finish a whole Man vs. Wild and never visit."

He says one of the last things he filmed was one the craziest he did while he was here. He jumped off a 37m high waterfall, with only vines and flax leaves tied to a tree to help lower him down.

Grylls, who is known to eat some daring things during his travels, also says he tasted one of the worst things he has ever eaten while in New Zealand - the tree weta.

"I thought it should be fine - I've eaten a lot of things like this. But it took me completely left field. I've never tasted something that tastes like you would imagine poo would taste."

Grylls is speaking in Auckland tonight about being the youngest ever British climber to conquer Mt Everest at just 23 years old. The money raised will go to both the families of the Pike River miners and the Christchurch earthquake relief.

He is in Wellington on Thursday night.