Many scientists believe the red-eyed tree frog developed its vivid scarlet peepers to shock predators into at least briefly questioning their meal choice. Their neon-green bodies may play a similar role in thwarting predators. Many of the animals that eat red-eyed tree frogs are nocturnal hunters that use keen eyesight to find prey. The shocking colors of this frog may over-stimulate a predator's eyes, creating a confusing ghost image that remains behind as the frog jumps away.
These iconic rain-forest amphibians sleep by day stuck to leaf-bottoms with their eyes closed and body markings covered. When disturbed, they flash their bulging red eyes and reveal their huge, webbed orange feet and bright blue-and-yellow flanks. This technique, called startle coloration, may give a bird or snake pause, offering a precious instant for the frog to spring to safety.
Red-eyed tree frogs, despite their conspicuous coloration, are not venomous. They are found in tropical lowlands from southern Mexico, throughout Central America, and in northern South America. Nocturnal carnivores, they hide in the rain forest canopy and ambush crickets, flies, and moths with their long, sticky tongues. Red-eyed tree frogs are not endangered. But their habitat is shrinking at an alarming rate, and their highly recognizable image is often used to promote the cause of saving the world's rain forests.
A female red-eyed tree frog has laid a batch of eggs on a leaf. She chose the spot carefully—the leaf hangs over a pond. When the eggs are ready to hatch, the tadpoles inside start swirling around vigorously. The activity breaks each egg open, releasing the little tadpoles. All the tadpoles wash down the leaf in a little stream of moisture from the hatching eggs, and—plop! plop! plop!—they land in the pond below.
Being green helps the red-eyed tree frog blend in with tree leaves. If the green camouflage fails and a predator spots a sleeping frog, it swoops in for what it thinks will be a tasty meal. But the awakened frog's eyes pop open, revealing their startling bright red color! Also, when the frog rushes to get away, it untucks its brightly colored legs. The predator is often so surprised by these sudden flashes of color that it is momentarily confused and hesitates. And while it does, the frog has a split second to make its escape!