Cyclosa ginnaga, a species found in Taiwan, China, Japan, and South Korea, hides from predators by looking like a pile of bird droppings. Cyclosa ginnaga incorporates a variety of silk decorations and other stuff such as prey carcasses, egg sacs, and plant materials into its web to make these look like splotches of bird feces. The spider, whose back is also white, then sits on these “bird dropping” decoration effectively invisible to its predators.
The webs’ shapes and sizes are nearly identical to many of the actual bird droppings seen on leaves. The contrast in color between the spider and its web decorations is also too small to be distinguished by its wasp predators.
To ascertain whether the camouflage actually works, a team of researchers headed by I.-Min Tso, an entomologist at National Chung Hsing University in Taiwan, caught wild spiders and darkened either the insect or its bird-dropping structure and set up video cameras outside to watch the spiders over several days. They observed that spiders that had blackened webs or bodies were much more likely to be attacked by predators, compared to spiders that weren’t manipulated in any way.