Monday, December 20, 2010

Red Jumping Spider - Backyard Tiger

I love spiders. They are fascinating in behavior. Their webs are works of art. Females are devoted mothers, risking their lives for their offspring (Green lynx spider, trapdoor spider). Yet I have to admit this large jumping spider startled both my husband and me.

Jumping spiders in California are typically the size a pencil eraser. They prowl the rosebush like ocelots stalking prey in the forest. With the best eyesight among spiders, most books say they can see up to two feet away from themselves, in vivid color. And when they call them jumping spiders, they are referring to their ability to jump about six inches, leaping rapidly to grab any insect prey before it can escape. 

But this red jumping spider (Phidippus formosus) surprised us with its size and capabilities. It was climbing up the outside of the house when it decided to walk across the second-floor bathroom window. When you compare it to the corner of the window, you can get an idea of its size. It would have easily covered a quarter with its body and legs. (It was close in size to the trapdoor spider that came in the house a few months ago.) The brick red of the top of its abdomen identifies it as a red jumping spider. If a typical jumping spider is like an ocelot, this spider was more like a tiger.

We got a great look at its underside and then it spotted us. It looked at us through the window and when I approached it outside, it spotted me coming when I was at least six feet away (3 times further than the books say they can see). It struck a defensive posture like a boxer, holding its pedipalps up in front of its eyes. I didn't really want to see how far it could jump.

Once it realized I wasn't a threat it continued its journey up the side of the house. I don't know where it was going. They supposedly build their burrows at ground level. This large female was headed toward the peak of our second story roof. Fast moving and on the prowl, she was climbing toward a golden polistes (Polistes fuscatus aurifer) wasp nest at the roof line. I don't think I would have wanted to be a wasp facing off with this voracious spider. But that is what natural balance is all about and the more we create a chemical-free habitat with native plants, the more biodiversity we are seeing in our backyard wildlife sanctuary.

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