The North Asian spider species Cyclosa ginnaga has come up with a creative form of camouflage: it disguises itself as bird poop.
Cyclosa ginnaga is a relatively small orb weaver spider, native to tropical forests in East Asia. While we have seen interesting strategies spiders use for hunting and staying hidden, such as pretending to be ants, Cyclosa ginnaga takes it to a different level altogether.
This silver and brown-colored spider is an attractive prey for predators, such as wasps. However, by making itself look like a big splat of white bird poop, it can still hang out in the open, hiding in plain view. The spider decorates its web in a spiral pattern with bits of dead leaves that ultimately resemble bird droppings, and beside providing camouflage, also attract prey.
A team of scientists led by I-Min Tso of the National Chung-Hsin University in Taiwan has confirmed that the animal uses itself and its environment to disguise itself as bird droppings. The researchers examined the surface area of 125 webs and 27 average-sized bird droppings in a Taiwanese forest. The results show that there is no substantial difference in the sizes of the droppings and the webs.
They also took a closer look at the differences in the hue of the spiders’ bodies and decorations, and found that predatory wasps were unable to distinguish between the spider and its web. On the other hand, however, the spider’s prey may be attracted to the sight to a greater extent.
To test their results in real life, I-Min Tso and his team sprinkled black carbon powder on the web decorations and some spiders to measure what happens to them. After analyzing 570 hours of footage, they were able to conclude that spiders that had their web decorations blacked-out were much more likely to be attacked by wasps.
“We provide empirical evidence for the first time that bird dropping masquerading can effectively reduce the predation risk of an organism. When the color signal of decoration silk is altered the predator attack rate increased significantly,” says I-Min Tso.
These spiders are an excellent example of how adaptable some animals are. And although pretending to be bird poo is a really peculiar method of camouflage, to say the least, it definitely pays off for these little guys.
Sources: 1, 2, 3
