27 Apr 2022

Six new species of wētā facing climate threat

From Afternoons, 1:45 pm on 27 April 2022

Six new species of wētā discovered at the bottom of the South Island could be extinct within a generation due to climate change, an expert is warning.

 Massey University professor Steven Trewick told Afternoons the wētā, which live in extreme alpine conditions, the species are only only found above the tree line.

Pharmacus chapmanae adult male. Mount Edgar Thomson, Aoraki / Mt Cook National Park

Pharmacus chapmanae adult male. Mount Edgar Thomson, Aoraki / Mt Cook National Park Photo: Danilo Hegg www.southernalpsphotography.com

“They're sitting in the alpine zone, they don't exist amongst the forest. So, they're specialised for that habitat that exists only where you go high enough, you get cold enough, dry enough. And those sorts of distinctive conditions that allow people to go skiing in the winter.”

These Alpine newly-discovered species can freeze, he said.

“If you find one when they're frozen and drop them, they'll break, they’re that frozen.”

And when spring comes they reanimate.

“They have the special capacity to freeze very close to zero degrees. So, they don't do what lots of animals in the northern hemisphere do when it gets cold, which is to stop themselves freezing, New Zealand insects go for it, let's just go with the flow, freeze up, stay where you are, and then reanimate when things get better.”

But climate change could render these wētā extinct in a generation, he warned.

“We're describing these species, but now we can, sit back and watch them go extinct within a lifetime. You know, that's the tragic thing about that.”

That’s even with the most optimistic scenarios for warming, he says.

“The realistic scenario for climate change is much more harsh, because as the IPCC told everyone a couple of weeks ago, we actually haven't done the things we promised that we were going to do.”

If Alpine creatures go, it’s a barometer of the impacts of climate change, he says. A situation he finds “heart-breaking”.

“The reality is that we have to live with this contradiction that we're describing stuff that is really doomed already.”

Wētā are beautiful and “utterly benign,” Prof Trewick said.

“If you stop and look at them, they are stunning. They're amazingly patterned, they've got eyes and a mouth and legs and all the parts that big animals have - they're not to be feared.”