Wednesday, March 21, 2007

Spiders Love 2 Snuggle

With a headline like that, of course I was going to click. While it is an interesting news feature about an observation an entymologist made about two species of whip spiders, after watching the video of the mama spider supposedly stroking her babies with her whip-like pair of legs, I can't say I am at all convinced the story deserves the headline.

It's not that I have a problem with spiders "loving" something, though that is probably not the term I would choose, unless of course I was writing a news feature... but anyway, that's beside the point.

What I take issue with is the evidence that the mama spider is actually touching her babies. You can see her "whips" moving around and the babies legs and bodies squirming, but it is hard to tell whether she's actually touching the babies. If she's not making contact, we could hardly call it "snuggling" in the classic mammalian sense, or reptilian, for that matter. Snakes and lizards form piles, presumably to thermoregulate their cold blooded bodies, and maybe they also derive some sensory pleasure from it above and beyond temperature. Perhaps these spiders derive some sensory pleasure from touch, and if so, that would be neat. But there is a long way to go from video of a mama spider moving her legs around in the vicinity of her offspring to concluding that she's touching them.

Now, suppose the researcher put some visible powder on the babies and observed the powder was removed by the actions of mom's whips. Then, I would be convinced. I'd even go so far as to say that's evidence of arachnid grooming behavior.

Grooming and touch are important social behaviors in a wide variety of animals. Such behavior serves a variety of functions which depend on the species. For most, the tactile contact improves basic hygiene. Getting rid of pesky parasites is the name of the game.

However for others, tactile contact lowers blood pressure and heart rate, which is an indicator of physiological stress. Primates and other mammals have been known to fall asleep while being stroked and groomed for just this reason. It's relaxing. For primates, tactile contact and grooming in particular, is way of making and keeping friends. Friends can be powerful allies. It is no accident that we humans speak of "grooming people for the job."

Spiders may love to snuggle. How about some evidence they at least touch? That way we can validly admit these two species in to the warm and fuzzy club. That is what this is ultimately about, afterall.

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