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What kind of spider is this? SE Michigan, light brown color, second picture less focused but w tape measure for scale. Thank you!

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No, this is not a Brown Recluse. There are several reasons for saying that, among them the fact that it's outside; it's hanging on a screen, and it doesn't look at all like a Brown Recluse - (Recluses don't have a rectangular cephalothorax "head end", and they have a bulbous abdomen, not that pointy-ended one this spider has). As for what it is, there are some good clues - first that rectangular-looking cephalothporax. That's pretty unusual in spiders, although it's not actually rectangular; it's just the central dark pattern is very blocky. Then, look at that color - kind of a creamy light mahogany rather than a real brown, and no darker/lighter patterns that the bigger wandering spiders that look like this would have. Finally, look how it's holding its legs - both the front pairs are close together. That's something you tend to see in two sorts of spiders - the big Argiope orbweavers, and the big Fishing Spiders and their relatives. Argiopes have a different body shape, pattern and color than this, and it would be a little unusual to find one this size hanging around not in a web. Fishing Spiders are generally dark-colored, and with more patterning than this, but there is a close relative that fits this image: the Nursery-web Spider, Pisaurina mira. Here's the Bug Guide page, and a representative photo:

https://bugguide.net/node/view/2919

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    $\begingroup$ John, excellent descriptive answer. I always appreciate how knowledgeable you are regarding spiders. Is this based on experience / collected knowledge, or do you use a key/guide? If the latter, which resource do you use? $\endgroup$ – theforestecologist Jul 5 at 21:16
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    $\begingroup$ Yes to echo @theforestecologist these are the sorts of species ID answers that I really appreciate: those giving a description of the attributes that led an expert to their conclusion. Well done, thanks for your work. $\endgroup$ – Bryan Krause Jul 5 at 22:52
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    $\begingroup$ Thanks - unfortunately, up until recently, there really weren't any particularly good field guides to spiders. There was the Zim Golden Guide, which had some common species, and fairly recently there was the Audubon photography-based Insects and Spiders, which had a few species as well. I learned using the very good Kaston lab guide, and collecting spiders enough to learn the various groups by eye. It's not too hard; just takes time and practice (and an interest in learning about spiders, of course). Nowadays there are several good websites, of which Bug Guide is the best. $\endgroup$ – John Robinson Jul 7 at 19:42
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    $\begingroup$ If I was learning now, I think it would be a bit easier because Richard Bradley's really excellent book covers many of the more common species, and does it very well. Still, there really is no substitute for field observation, so you can recognize the patterns of stance, shape/colors and behavior. You may not know the specific spider, but you generally have a guidepost to help you narrow it down. It's like with birds and trees and flowers, but without the useful pocket guides.. $\endgroup$ – John Robinson Jul 7 at 19:48

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