Red-eyed Tree Frog
Agalychnis callidryas
One of the most iconic critters of tropical rainforests, just about everyone recognizes the Red-eyed Tree Frog – those bulging scarlet eyes can’t be missed! Common in the tropical rainforests of Central America, this ever-popular frog has a bright green body with blue-and-yellow-striped flanks, vibrant orange toe webbing with sticky pads on the end of each toe, and bright red eyes with vertical black pupils. Its pale underside has thin, soft skin, while its back is thicker and rougher. Medium-sized for a tree frog, at 7 cm it is about the size of a teacup, and like other tree frogs, females are larger than males.
The Red-eyed Tree Frog is arboreal and nocturnal, and spends its days sleeping in the canopy of the rainforest, where it is seldom encountered during the day. It will often tuck itself away into the leaves of tank bromeliads. At night, especially during the breeding season, it descends to the ground to hunt and breed, and can be found in riverine and pond habitats. It is an excellent jumper with its long, thin but powerful legs, earning it the nickname “monkey frog.” Red-eyed Tree Frogs are insectivorous, preying on a wide variety of insects. They use their long, sticky tongue to grab their prey. Despite its seemingly daunting coloration, the Red-eyed Tree Frog is not poisonous; rather, it relies on those bright colors and especially its big red eyes to startle potential predators, a trait called startle coloration. During the day, it folds in its legs and arms snugly up to its body and covers its brightly colored flanks and toe webbing, enabling it to blend in nicely with a green leaf. It extends its third eyelid, called a nictitating membrane, over its red eyes – this way it can still see movement and fluctuations in light and, more importantly, potential predators as it rests. If a predator comes near, the frog opens its big eyes and exposes its bright colors, giving it a second or two to distract the predator and a chance to escape. They are good swimmers and climbers.
During the breeding season, which occurs during the rainy season in Panama from May to November, males work hard to attract females. They shake branches to keep rivals at bay (a form of communication using vibrations!). They advertise their fitness to females vocally, giving loud “chack” calls. Once engaged in amplexus, the female will carry the male around on her back for up to several hours while she is ovipositing. She lays a clutch of eggs, usually around 40, in a gelatinous blob on a leaf above water. The slimy-looking jelly protects the eggs from dehydration. The eggs hatch after 6 or 7 days and drop into the water below. If they happens to miss the water, tadpoles can stay alive on dry ground for up to 20 hours. Successful tadpoles will then spend the next month to several months developing in the water. But, the water is not necessarily the safest place for them; tadpoles are preyed upon by fish, dragonflies and water beetles, while snakes and wasps target the eggs. Once they reach a point in their development in the water, they will undergo metamorphosis to the adult frog. The duration of the immature stage depends greatly on the environment. Juveniles are typically brown and have yellow eyes. The eye color changes to red once the frog is sexually mature, anytime between 1 and 2 years. Red-eyed Tree Frogs have a lifespan of approximately 5 years.
Even before they develop even somewhat frog-like characteristics, the embryos exhibit an interesting behavior called phenotypic plasticity, which is the early hatching of the eggs in response to a disturbance in order to protect themselves. In most cases, it is when a predator is nearby.
Red-eyed Tree Frogs range from Mexico to Colombia, and can be found throughout Panama. They are widely distributed and presumed to have large populations, but of course are at risk of habitat loss, as are all rainforest animals. They are found occasionally around the Canopy Family lodges.
More cool facts about the Red-eyed Tree Frog:
– The species radiated approximately 10 million years ago. Frogs in general have been in the fossil record for hundreds of millions of years.
– They live in bromeliads and palm fronds, where there is more moisture, in the dry season.
– They close their bulging eyes to help them swallow
– A group of Red-eyed Tree Frogs is called an army
The Red-eyed Tree Frog is not as susceptible as other species to chytridomycosis, the fatal fungus killing frog populations worldwide dramatically.