Wolf Spider — Eight-Legged Genius
You may enlarge any image in this blog by clicking on it. Click again for a full screen image.
Recently, I posted an image that I’d made of a Wolf Spider. I had another encounter with one of these fascinating creatures last night while I was walking at Sabino Canyon and I have a couple more images to post.
Wolf Spiders are huge as spiders go. Certainly, not as large as tarantulas, but big enough. This individual is more than two inches in diameter (including its legs) and would sit comfortably in the palm of my hand.
These giant spiders are harmless. They have no interest in interacting with humans. One might bite if molested but its bite probably would be no more painful or dangerous than a bee sting.
The more I read about spiders the more fascinating I find them to be. They are certainly among the more intelligent invertebrates that we encounter, far more intelligent (as we measure intelligence) than most insects. A spider’s brain occupies nearly all of the spider’s cephalothorax (the front part of the spider’s body). Indeed, in some species, the brain is so big that it actually extends downward into the upper parts of the spider’s legs. Although tiny in absolute size when compared to our brains a spider’s brain is larger in proportion to its body than is a human’s brain. That big brain is what enables spiders to: coordinate their eight legs so effortlessly; move quickly and efficiently to capture prey; and in some species, to spin elaborate webs. But, more than that, a spider’s large brain endows it with a certain intelligence. Spiders are not tiny philosophers, poets, or physicists. But, they have learning abilities that sets them apart from other invertebrates. Spiders have been taught to solve mazes. They seem to be able to adapt to changes in their environment. Spiders learn from experience and they will avoid adverse stimuli once exposed to them.
That giant brain connects to a sensory apparatus that is unique and amazing in its own right. Spiders have eyes and can see. The Wolf Spider has eight eyes and its vision is relatively well developed for a spider. It has a panoramic range of vision that extends to close 360 degrees. But, vision is not its most important sense. Spiders find their way around their environment by responding to vibrations. Those hairs that cover the Wolf Spider’s legs are actually sensory organs. With them the spider can sense changes in air pressure that we’d never notice. Although spiders lack ears they can “hear” what’s going on around them by sensing vibrations, including the vibrations in air caused by sound waves. A Wolf Spider doesn’t need to see something in order to be aware of its presence. It can sense the approach of prey or a potential predator in total darkness, identify the intruder, and form a judgment about what to do about it. Spiders also have smell and taste receptors on their legs.
So, next time you see a spider, resist the urge to step on it or to run away. Stop, and look closely at it. You’re staring at an invertebrate genius with highly developed neurological capacities, one that deserves our respect and admiration.
Images made with a Canon 5DS-R, 180 mm f3.5L Macro Lens, assisted by Canon 600EX-RT Speedlite, M setting, ISO 250, 1/60 @ f20.