New Zealand: Entry 3

3 March 2003: Rotorua, New Zealand

Subject: New Zealand

Waitomo Caves

I've been travelling for more than six months now and I've only just visited the first cave of the trip! (Well, that's if you don't count the lava tube cave on Easter Island, which I don't think I do.) So to make up for it I went to not one but two!

It seems odd to me that New Zealand has limestone since not far from Waitomo you can see the geothermal activity and volcanic peaks where the Pacific plate meets the Austalian plate (or whatever that one is called). But they do and there are some quite substantial caves at Waitomo, about half way down the East coast of the North island.

What makes these caves special is that they aren't as pitch black as almost all others - they are full of Arachnocampa luminosa larvae, or glow worms to you and me. The adult insects lay their eggs on cave roofs and outdoor rock overhangs. When the larvae hatch they build themselves a "nest", which is a tube made of a mixture of mucus and a silk-like material. From this tube they dangle silk filaments coated with sticky blobs. And they sit and wait, spider-like, for something to wander into their trap. Mostly they prey on insects that have wandered into the cave by mistake. But the crucial thing is that they lure their prey with light. A chemical reaction in their gut gives off a green-white glow and seen from below you can forgive an errant gnat for thinking that it was looking at the star-studed sky.

So I took the regular trip to the glow worm caves, which starts off like every guided cave tripin the world with a selection of formations that look like elephants, old women and similar rubbish. But then you get in a boat and float gently downstream with the lights off looking up into the roof of the rift passage where they say there are ten thousand glow worms. It really does look a lot like the night sky, though whereas the stars are randomly distributed these creatures seem to keep a minimum distance from their neighbours. It's absolutely fabulous and not to be missed.

But for some more excitement I also went on a "black-water rafting" trip, which involves putting on a wetsuit and floating through a similar cave sitting in a big inner tube. It might have some similarity to (outdoors) white-water rafting when the water level is higher, but for us it was quite gentle and we had plenty of opportunity to enjoy the view of the lights in the roof.

Finally, Waitomo has a Cave Museum which is also excellent; it has a great audio-visual about the glow worms and some interesting stuff about cave exploration, geology, and cave life - including a live cave eel in an aquarium! I thoroughly recommend all three.

So this morning I packed up my tent (in the rain...) and came to Rotorua, in the centre of the North Island and near to the most famous volcanic activity. You can smell the sulphur as soon as you get off the bus! So far the town looks rather uninspiring, but I'll see what there is to do over the next couple of days.