That Spider Looks Like Shit

Bird shit, to be specific. In a sad-for-you but funny-for-me play by evolution, the Cyclosa ginnaga orb-web spider has somehow learned to fashion its nest so, when sitting in it, the spider looks like bird poop. This is, like most evolutionary advances, done in an effort to avoid predators (thankfully, these spiders don’t dress up like poop to find a mate). To predators such as ants and wasps, the color of the spider’s body and its web decorations are indistinguishable from each other and from bird dukes. A group in Taiwan published these findings in a recent issue of Scientific Reports (which is open-source, hooray).

(a) Our spider friend pretending to be poop and (b) a reference in case you don't know what bird poop looks like.

(a) Our spider friend pretending to be poop and (b) a reference in case you don’t know what bird poop looks like.


In the paper, the authors noted  that many have pointed out that the spider looks like shit, but no one has ever done a scientific experiment to confirm this “hypothesis”.  So they gathered up 10 spiders and waited for them to spin their webs. Then they measured the specific wavelengths of light emitted by the spider’s bodies, their webs, and, of course, bird turd for comparison. Using a computer program to analyze the emitted patterns, they found that bees and wasps couldn’t distinguish between the spider and its web—it all looked like one big blob to them. What’s more, they couldn’t distinguish the spider-web blob from a pile of bird dinks either.

Then, they went out in the wild and decided to color some of the webs black so that the spiders could no longer hide. In short: “When the color signal of decoration silk is altered the predator attack rate increased significantly,” I-Min Tso, an ecologist at Tunghai University and co-author of the paper, told Smithsonian Magazine. The spiders not only needed to blend in with their web, but the entire setup had to blend in with the background, the forest. Black was just too obvious of a disguise.

Oddly enough, “it’s really not all that uncommon. Several other spiders, like Bolas spiders, also use this disguise,” Cornell University arachnologist Linda Rayor, who was not involved in this study, told National Geographic.

So the next time you think you look like shit, remember our little friend C. ginnaga and realize you don’t look so bad after all.

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