Spider Disguises Itself as Bird Droppings, Scientists Discover
A species of orb-weaver spiders has been found to hide from predators by disguising itself and its web as a blot of bird droppings.
In a new paper published in Nature [http://www.nature.com/srep/2014/140529/srep05058/full/srep05058.html], biologists led by I-Min Tso at National Chung-Hsin University in Taichung, Taiwan analyzed the coloration of the Cyclosa ginnaga spider and its web patterns and determined that it disguises itself as bird droppings. The spider has a silver body, and juveniles create a white disc on their webs, the color and size of which are consistent with the appearance of bird droppings.
Tso and his colleagues believe this is a mechanism to avoid predators. Experiments in which the spiders had their webs blackened with carbon powder showed that wasps attacked the spiders far more often. The researchers concluded that "the colour of C. ginnaga's body and decorations were indistinguishable from bird droppings in the eyes of their predators." However, before it can be proven that this is an intentional form of camouflage to hide from predators, more experiments need to be conducted to see how wasps react to bird droppings, the researchers write.
Spider coloration tends to either be a factor of hiding from predators or attracting prey. Juveline C. ginnaga's bright silver coloration is conspicuous, which normally results in attracting predators with other bright-colored spiders. It had been hypothesized that the C. ginnaga and its web formed a disguise, but it had not been experimentally investigated until now.
What a crappy disguise.
Source: Popular Mechanics [http://www.nature.com/srep/2014/140529/srep05058/full/srep05058.html]
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A species of orb-weaver spiders has been found to hide from predators by disguising itself and its web as a blot of bird droppings.
In a new paper published in Nature [http://www.nature.com/srep/2014/140529/srep05058/full/srep05058.html], biologists led by I-Min Tso at National Chung-Hsin University in Taichung, Taiwan analyzed the coloration of the Cyclosa ginnaga spider and its web patterns and determined that it disguises itself as bird droppings. The spider has a silver body, and juveniles create a white disc on their webs, the color and size of which are consistent with the appearance of bird droppings.
Tso and his colleagues believe this is a mechanism to avoid predators. Experiments in which the spiders had their webs blackened with carbon powder showed that wasps attacked the spiders far more often. The researchers concluded that "the colour of C. ginnaga's body and decorations were indistinguishable from bird droppings in the eyes of their predators." However, before it can be proven that this is an intentional form of camouflage to hide from predators, more experiments need to be conducted to see how wasps react to bird droppings, the researchers write.
Spider coloration tends to either be a factor of hiding from predators or attracting prey. Juveline C. ginnaga's bright silver coloration is conspicuous, which normally results in attracting predators with other bright-colored spiders. It had been hypothesized that the C. ginnaga and its web formed a disguise, but it had not been experimentally investigated until now.
What a crappy disguise.
Source: Popular Mechanics [http://www.nature.com/srep/2014/140529/srep05058/full/srep05058.html]
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