The researchers termed this novel camouflage technique, “edge diffusion.” “By having translucent legs and resting with the legs surrounding the body, the frog’s edge, where it meets the leaf, is transformed into a softer less contrasting gradient, blending the frog and leaf together more smoothly.” “Visual systems are very sensitive to edges where two different colors meet, and thin, highly contrasting edges are particularly conspicuous, Barnett tells Tibi Puiu of ZME Science. This muddles the outline of a sitting frog, creating diffuse edges that predators are less likely to recognize. The researchers also report that the frogs’ legs are more translucent than their bodies. Changing brightness in this way allows the frogs to more closely match the green of the leaf they happen to be sitting on. The researchers found the frogs always looked green, but that they brightened or darkened depending on the background, per the paper. First, they used computer analysis to assess the color and outline of the frog in each photo, according to the Guardian. The researchers then conducted three experiments. To test the frogs’ camouflage, the researchers photographed 55 glass frogs on green leaves and on white backgrounds.
“If predators cannot see straight through the frogs, why do glass frogs have transparent skin at all, and not the opaque camouflaged patterns of other tree frog species?” Barnett, tells the Guardian. For this reason, Barnett says glass frogs are better described as translucent rather than transparent, and it was this puzzling mélange that Barnett and his team sought to investigate. That’s one reason why on this list of ten glass-like animals created by Ella Davies for BBC Earth in 2015, the glass frog is the only land animal with a partially see-through body.īut even glass frogs are not totally transparent they all have green backs and their glass-like tummies are usually pressed against a leaf. But, unfortunately for land animals, the trick works better underwater, where the watery backdrop keeps critters’ fluid-filled insides from standing out, says James Barnett, a frog researcher at McMaster University and lead author of the paper, in a statement. The reason for their unique appearance has gone mostly uninvestigated, but new research has found the frogs’ glass-like skin helps them blend in and avoid being spotted by predators, reports Nicola Davis for the Guardian.īeing see-through seems like the ultimate form of camouflage. The glass frogs of Central and South America aren’t named for their fragility it’s because their bones, intestines and beating hearts can be seen through the skin covering their torso and limbs.