Wednesday, 1 January 2014

Christmas spidering

I went spider hunting over Christmas. Things did not at all go to plan.

I had planned to drive from Christchurch down to Waimate, search for Cantuaria there, then go and search Oamaru. I was then going to go down to look for two species in Dunedin, drive to Clydevale and look in two locations around there, then head back and check Warrington Beach on the way.

What actually happened was some weather, and the car broke down a lot.

I managed to look around Dunedin during a couple of hours of respite, during which I got very muddy and slid around a lot. I also learned there are many clay banks around Dunedin, and many tiger beetles, the larvae of which make small round holes in banks and seem to exclude Cantuaria.

My long-suffering friend came out to help me look. He's helped me with fieldwork before and even though he doesn't care for spiders much, he spent his day off climbing hills and clay banks and looking for things that he has never seen before. That's what I call a good field assistant.

I got to the point where I had been in Otago for nearly a week and not found a single Cantuaria. There were other cool spiders, like this Cambridgea:

If you look at his eye pattern, it looks like a smiley face! Below his eyes are the massive chelicerae, and next to those are thin arm-like appendages with bulbous structures on the end. Those are the palps, which are the male genitalia.

But I was not meant to be looking for Cambridgea. I began to think that Cantuaria were all around me but I was just not looking hard enough, or perhaps I didn't have enough skill to find them. Every time I saw a clay bank I would look so closely along it that my nose would nearly touch the clay, in case the burrows were there but I was missing them.

Then I drove to Black Bridge Road, which turned out to be a gravel road in the middle of nowhere (and of course the car decided to break down there as well). There were many clay banks there as well, but when the car broke down I searched the bank right next to it and found this:

It was the best Christmas present I could have got - confirmation that not only do Cantuaria exist away from places where there are advisors and spider enthusiasts, but that I could find them. I found around 20 more burrows, but I could have found more if I'd kept looking. Some of the holes were pretty big, others rather small.

Some lids were neat and round, others had broken up profiles. All the burrows were smooth and round inside, and lined with silk. Many of the burrows were wider than the lids, so that there was a gap between the edge of the lid and the edge of the burrow. I wonder if those lids had been built when the soil was wet, then shrunk as they dried, or perhaps the spider had only recently moulted and only got round to adjusting the size of the burrow but not the lid.

I harnessed up the beetle, ready to work when the sun went down.

At first, no spider came out - the beetle did not seem tempting enough. Then I used my advisor's trick of tickling the entrance with a blade of grass. That was successful in getting the spider to shoot out, then quickly jump back into its burrow. Using the grass to get the spider's attention, then the beetle to tempt it fully out of the burrow, seemed to be the best method. These spiders were quite unlike the Cantuaria dendyi that we had caught last time - they were larger, blacker, and quicker. When the C. dendyi were about to attack the beetles, the lid began to open a little and you could sometimes see the spider underneath - but with these spiders (which are probably C. depressa), the lid remained closed for ages and you started to think that the spider was not going to come out. Then, just as you are thinking of moving on to another burrow, the lid flies open and a spider explodes out. The first few made me jump.

I collected four, had a look at the car, poked one of the spark plugs back in and topped up the oil. Apparently that was all that was wrong with it that time. Then I drove back, happy that I did at least manage to collect from one population of Cantuaria.

A note about Christmas and other times of traditional socialisation and celebration

I expect that, for most international students, Christmas and other celebration times can get a bit lonely. You're away from your family, most people have left university to be on holiday (but you are expected to work), and you have no money. Important things to remember are that soon the holiday season will be over and you will be no worse off for having experienced it, as self-pity soon fades when you are surrounded by exciting and difficult things to do. It is also a good idea to find people who are both nice and in the same situation as you, and spend Christmas with them. That way you kind of make your own makeshift family. I don't normally get bothered by these things though, because Christmas in NZ doesn't feel like UK Christmas at all, and because I don't much like spending my days with heaps of drunk people anyway.

Merry belated Christmas to all, and happy New Year!


  1. I'm enjoying this blog - I'm surprised that you don't have more comments.

  2. I haven't advertised it much yet because nothing is really going on at the moment. I'm glad you're enjoying it - as far as I know you, my mam, and my friend Erin are my only audience.