My New Room Mate

WARNING: This post contains graphic images of spiders. People with spider phobias may not wish to view the rest of this post.


Have you seen a spider with its prey, and been compelled to watch with fascination and intrigue, perhaps with a degree of disgust or a measure of fear thrown in? Or perhaps you've watched with curiosity, a spider weaving its delicate web and wondered how such a little creature could engineer such a beautiful death trap?

A couple of days ago, I noticed I had a little friend living by my window. He (or she) is much smaller than previous room mates I've had, such as this lovely fellow who kept me company a few years ago when I was in Nigeria: 

I was sitting on my bed, with my back leaning against the wall, reading a book one evening. This guy had been sitting quietly at the top of the wall, next to the ceiling, and I hadn't given much thought to his presence. All off a sudden I see movement out the corner of my eye, and turned to see him almost fly down the wall and stop, next to my head. Recovering from the surprise, I noticed he'd just caught a moth. I sat and watched him with fascination and a sense of awe, that I'd been privileged to be a witness to his hunt and subsequent feed.

While I do not know what sort of spider my Nigerian room mate was, my new little friend is a jumping spider. Jumping spiders belong to the family Salticideae, and are incrediably bright for being such little creatures with miniscule brains.

There are two major categories of spiders. There are sit and wait spiders. These are those that build webs to catch their prey, and they typically just sit out of sight near their web until some unsuspecting insect flies into it and gets caught up in the threads. Other spiders are active hunters. Both my Nigerian room mate and jumping spiders are active hunters. They still produce silk, which they might use as a saftely line (as with the jumping spiders) or to make their nests or egg sacs etc, but they do not construct webs to catch prey. Instead they are like the lions of the invertebrate world and actively stalk their prey.

As jumping spiders are active hunters, they have great vision with their eight eyes and spatial mapping abilities. Web building spiders have special tapping signals that the males tap out on the female's web, to tell her that he isn't prey but a potential mate. Some jumping spiders even mimic these tapping signals, pretending to be a potential mate, enticing the female out, where instead of finding a mate, she gets eaten! Spiders can be smart! They are incredible creatures. 

Anyway, I'd like you to meet my new little friend :)

Don't you wonder what those dark eyes are seeing and what is going on in his little brain? If you are in Christchurch, you might enjoy this seminar by Ximena Nelson, a scientist who studies jumping spiders.