Are Red-Eyed Tree Frogs Poisonous? Bright but Harmless

Why people think red-eyed tree frogs are poisonous

It is an easy mistake to make. In nature, bright colors often signal danger. Poison dart frogs, coral snakes, wasps and many caterpillars use vivid reds, yellows and blues to say “do not eat me”. The red-eyed tree frog (Agalychnis callidryas) is just as colorful, and it lives in the same Central American rainforests as several poison dart frogs, so many people assume it must be toxic too.

The difference is in how the colors are used. A poison dart frog shows its warning colors all day long, hopping openly over the forest floor. A red-eyed tree frog hides its bright parts while it sleeps on a leaf, showing only a green back. It flashes its colors only for a moment when it is disturbed.

How the red-eyed tree frog defends itself instead

Without strong toxins, the frog depends on three layers of defense:

1. Camouflage. By day it presses itself flat against a green leaf, eyes closed and legs tucked in, and looks like part of the plant.
2. A startle display. If touched, it opens its red eyes and reveals its flanks and orange feet. The sudden change may make a predator pause. The idea is explained in why do red-eyed tree frogs have red eyes?.
3. Escape. It then leaps or climbs quickly away into the foliage.

The best evidence that the frog is not chemically protected is its list of predators. Cat-eyed snakes eat its eggs and adults, and birds, frog-eating bats, large spiders and other animals also eat the frogs. A truly toxic frog would be avoided by many of these hunters.

What is in red-eyed tree frog skin?

All frogs have skin glands, and the red-eyed tree frog is no exception. Its glands produce mucus that keeps the skin moist and helps limit water loss, which is vital for an animal that breathes partly through its skin. Like many frogs, it also secretes small proteins called peptides, some of which act against bacteria and fungi on the skin. Researchers study frog skin peptides of this kind for possible medical uses.

These secretions are a normal part of amphibian biology, not a poison aimed at large predators. The red-eyed tree frog is not known to have caused harm to people through its skin. Some of its larger relatives in the leaf frog family produce much stronger peptide secretions, but the red-eyed tree frog is not among the frogs considered dangerous.

Red-eyed tree frog vs poison dart frog

Poison dart frogs gain their toxins from the ants, mites and other small arthropods they eat. Frogs raised in captivity on ordinary insects lose most of their toxicity. The most toxic of all, the golden poison frog of Colombia, carries batrachotoxin, one of the most powerful natural poisons known. You can read how that works in why are poison dart frogs poisonous? and see other examples in the list of the most poisonous animals.

Poisonous vs venomous: a quick note

The two words are often mixed up. A poisonous animal is harmful if it is eaten or touched, because the toxin is in its body or skin. A venomous animal injects toxin through a bite or sting, as snakes, scorpions and spiders do. Almost all frogs, poison dart frogs included, are poisonous rather than venomous, and the red-eyed tree frog is neither venomous nor dangerously poisonous.

Is it safe to be near red-eyed tree frogs?

Yes. Visitors to Costa Rica, Panama and other countries in the frog’s range often see red-eyed tree frogs on night walks without any risk. The frogs do not attack, and their skin is not a danger to people.

The real concern runs the other way. Amphibian skin is thin and absorbs substances easily, so sunscreen, insect repellent and natural oils from human hands can harm a frog, and handling causes stress. Diseases such as chytrid fungus can also be spread between ponds on hands and boots. The best way to enjoy a red-eyed tree frog is to watch and photograph it without touching it.

Learn more about the species in the red-eyed tree frog profile.