Photo of the Week – May 5, 2017

During the last week, I’ve been lucky enough to find and photograph two different wolf spiders, so I figured I should probably dedicate a short blog post to them.  The first wolf spider I found was a cute little bugger out in the prairie the other day.  I was out looking for monarch eggs and caterpillars and saw the spider scurry between clumps of vegetation.  Since I had my camera in hand, I stopped and had a visit.  The second spider was in our basement and was considerably bigger (2 inches in diameter with legs).  I took it outside where it could be happier, and photographed it before letting it roam freely in our garden.

This big beautiful wolf spider was in our basement before I put it back outside.

There are a lot of big fuzzy spiders that resemble wolf spiders, but true wolf spiders have a characteristic eye pattern that sets them apart.  If you look at the above photo, you can see that there are two large eyes above a straight row of four smaller eyes.  If you look even closer, you might be able to see two additional eyes behind the big ones that point up and to the sides.  You can see those last two eyes more clearly in the photo below.  The layout of those eight eyes is unique to wolf spiders, so if you ever wonder if a big fuzzy spider is a wolf spider, just look it in the eyes and you’ll know.

In this photo, it’s easier to see the wolf spider’s non-forward facing eyes.

There are more than 2,000 species of wolf spiders across the world, and they are a fascinating group of creatures.  Although they are free-roaming spiders (they don’t create a web and hang out on it), they still use ambush as their primary means of hunting.  They’ll usually sit quietly and wait for prospective prey to come within striking range. Wolf spiders hunt mostly at night, and their eyes are well-adapted for seeing in low light.  However, wolf spiders are also very adept at sensing and using vibrations to identify their prey.  Their hairy legs aren’t just for looks; they also act as part of a complex system of vibration sensors.  Wolf spiders can distinguish between patterns of wing beats or footsteps to help them determine what kind of creature is coming near.

This small wolf spider was out in the prairie while I was looking for monarch caterpillars.  Its body and legs were about a half inch in diameter.  Note the distinctive eye pattern that characterizes it as a wolf spider and the different kinds of hairs on the legs.

My daughter made me proud the other day by telling me she was able to impress her college friends with some of my favorite spider trivia: the reason spider legs always curl up when they die.  Spiders have flexor muscles on their legs (muscles that pull the legs toward their bodies) but not extensor muscles to push them back out again.  Instead, they use hydraulic pressure to extend their legs.  A fluid called hemolymph is pushed into the legs, counteracting the flexor muscle pressure enough to extend the legs.  It sounds like a cumbersome system, but if you’ve ever seen spiders run and jump, it’s clear that it works very well.  When a spider dies, it no longer has hydraulic pressure in its legs to counteract the flexor muscles so the legs naturally curl up toward the body.

Don’t you just love spiders?  Of course you do.

Here’s the big female one more time, just before she turned away to go explore our garden.

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About Chris Helzer

Chris Helzer is the Director of Science for The Nature Conservancy in Nebraska. His main role is to evaluate and capture lessons from the Conservancy’s land management and restoration work and then share those lessons with other landowners – both private and public. In addition, Chris works to raise awareness about the importance of prairies and their conservation through his writing, photography, and presentations to various groups. Chris is also the author of "The Ecology and Management of Prairies in the Central United States", published by the University of Iowa Press. He lives in Aurora, Nebraska with his wife Kim and their children.
This entry was posted in Prairie Insects, Prairie Natural History, Prairie Photography and tagged , , , , , . Bookmark the permalink.

11 Responses to Photo of the Week – May 5, 2017

  1. shoreacres says:

    On my first visit to a piece of burned prairie, five days post-burn, I was delighted to find a spider living in a crawfish claw at the entrance to an old mound. And just this week, I found a crab spider lurking about inside the fluff of a thistle. The more that I see these creatures — and I’m seeing them much better now, thanks to a macro lens — the more I admire them. I didn’t know about their hydraulic system: that’s fascinating beyond words.

  2. Ray Guidi says:

    Of course you do.

  3. Chris Muldoon says:

    The comment under the last picture, “Here’s the big female one more time”…. How do you distinguish a male spider from a female one?

    • Chris Helzer says:

      Chris, sorry for the delay in getting back to you on this. I wish I could tell you there were certain anatomical characteristics I was relying on to make the male/female call, but the truth is I can’t tell wolf spiders apart but always assume the giant ones are females because males are quite a bit smaller. I do the same thing with snakes. Small snakes are unknown, but big ones are always females. It’s a total cop out, but there it is.

  4. Jordy Jordahl says:

    Chris – I don’t always get to read your posts but when I do, they normally make me smile. Enjoyed learning and seeing wolf spiders.

    Have a great day!

    Jordy

    Harald (Jordy) Jordahl, Director
    America’s Watershed Initiative

    Mobile (608) 445 8543

    http://www.americaswatershed.org/

    From: The Prairie Ecologist
    Reply-To: The Prairie Ecologist
    Date: Friday, May 5, 2017 at 7:22 AM
    To: Jordy Jordahl
    Subject: [New post] Photo of the Week – May 5, 2017

    Chris Helzer posted: “During the last week, I’ve been lucky enough to find and photograph two different wolf spiders, so I figured I should probably dedicate a short blog post to them. The first wolf spider I found was a cute little bugger out in the prairie the other day. I”

  5. Lloyd Crim says:

    Great post! Thanks!

    Lloyd

    On Fri, May 5, 2017 at 7:22 AM, The Prairie Ecologist wrote:

    > Chris Helzer posted: “During the last week, I’ve been lucky enough to find > and photograph two different wolf spiders, so I figured I should probably > dedicate a short blog post to them. The first wolf spider I found was a > cute little bugger out in the prairie the other day. I” >

  6. Nancy Webber says:

    I enjoy walking at night in the prairie here in central Texas and shining a light into the grass to see the thousands of little eyes sparkling out there. Also I love to see the big mama wolf spiders with all their tiny babies clustered on them in the fall.

  7. Patrick says:

    Seriously misunderstood creatures, spiders are. It’s the eyes, I reckon, they unnerve some folk. -Hagrid

    I have burrowing wolf spiders on my prairie and the entrances to their burrows (nickel to almost quarter-sized in diameter) are usually built up with mud and grass. Have you seen those on the PRPs?

  8. Great shots of a very fascinating creature. While we’re not always looking for them we always stop and take a few pictures when one is seen. Then the fun part, trying to ID what you’ve just photographed.

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