Seeing Red

What am I looking at?

This is a red-eyed tree frog (Agalychnis callidryas) comfortably hanging from a branch, as they do in their natural habitat. You can see its distinctive red eyes (1); its broad, padded feet (2); and the blue coloration on the sides and bottom of its legs (3).

Click on the right arrow to see more views of this colorful tree frog.

Biology in the background

The red-eyed tree frog is native to Central America and northwestern South America. They breed readily in captivity and are often kept as pets. They are nocturnal predators who mainly hunt insects. Their large eyes allow them to see very well in low light and to track motion in the darkness.

In many frogs, bright colors like this signal to predators that they are poisonous to eat or even touch. However, the red-eyed tree frog is not poisonous; instead, its colors serve as a defense mechanism to confuse and startle predators. This phenomenon is called “dazzle coloration” or “decoy effect.”  When it’s at rest, the frog’s colors are hidden under its tucked limbs. But when a startled frog suddenly reveals its colored flanks, it creates a brief, intense visual stimulus that can distract the predator and disrupt its aim by leaving a temporary after-image on the predator’s retina.

This frog can grow up to 7.5 centimeters in length, about the size of a human pinky finger.

Technique

These images were created using macrophotography.