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Red-eyed Tree Frog

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Scientific name: Agalychnis calidryas
Family: Hylidae
Order: Anura
Class: Amphibia

PHYSICAL CHARACTERISTICS:

The average size of Agalychnis callidryas is no more than three inches. The Red-eyed Tree Frog is usually an extremely bright green with cream and sky blue along the rib and groin area. The hands and feet are marked with a bright orange and are also lined with blue and cream. The most recognizable physical characteristic of Agalychnis callidryas are their bright red eyes. 

Agalychnis callidryas has other adaptive features. The long limbs on these frogs are better suited for climbing than swimming. Another feature is the sucker pads on the end of each digit. These pads allow the frogs to stick to various objects and provides better traction on wet leaves and branches. Most of the frogs that are in the Hylidade family have a third eye lid called a nictitating membrane. The purpose of this membrane is to shield the frog's sensitive eyes from various dangers. The lid is often brightly colored and does not completely restrict it's vision.

DISTRIBUTION and HABITAT:

Agalychnis callidryas are found in the neotropical rainforest of central America. This species of frog is completely arboreal or tree dwelling and they are excellent jumpers. These frogs rarely descend to the ground and move in a very stealthy and deliberate manner. They are completely nocturnal.

BEHAVIOR:

Bright markings along the sides and on the limbs function to reduce predation. Most of the predators that prey on Agalychnis callidryas often rely on their vision. When the frog moves to avoid the predator the bright colorations come into view. Because the predator is so locked onto it's target, when these bright colors flash into view (hence their name, flash colors) they throw off the predator. This is achieved by leaving a ghost image in the visual field of where the frog was originally. This confuses the predator and gives the frog time to hide. In other cases, these bright colors often startle the predator and throws them completely off. These flash colors are often well hidden and are only shown when the animal is moving.

DIET:

Red-eyed Tree Frogs are carnivores and their diet consist of any animal that will fit in their mouths, even other frogs!

BREEDING:

The breeding season of Agalychnis callidryas is during the months of October through March. The mating ritual consists of males croaking (often all in unison) trying to attract a female. Many times various males will compete for a single branch area. They wrestle until one of them falls off the branch. Then when there is only one male left (all the competition is gone), the male then latches onto the back of the female with it's legs. From there the breeding process begins. Once a male has latched onto a female for mating, other males will try to latch onto the couple.  This takes place while the female is holding onto the underside of a leaf. The female has to support the weight of all the frogs until they finish their wrestling match and only one is left.

Next, the pair participate in a process called amplexus. In this process the pair hang up side down under a leaf that is overhanging a water source. The female supports the entire weight of the pair with her legs and digit pads. She releases her eggs one at a time then the male fertilizes the eggs. Each batch of eggs is called a clutch. The female must keep her bladder (this stores the water to hydrate the eggs) and body well hydrated during this process. The eggs require a large amount of water for survival, so females rehydrate by descending from the trees and entering a pool of water.

When the female enters the water, the wrestling continues again. The male that was latched onto the back of the female runs the risk of getting knocked off again and must try to hang on. In many cases when the female heads back up to the leaves she may not have the same mate that she came down with. After this process is complete the eggs are left to mature. In a few days the eggs hatch and the tadpoles are released into the water to mature. The water that was in the eggs helped to expedite the tadpoles exit and also prevented dessication. The tadpoles then mature in the water and later turn into frogletts. The frogletts take to the land and head for the trees to continue the rest of their lives.

Agalychnis callidryas is not endangered nor threatened. The environment that they live in is shrinking. Many wildlife conservation groups are petitioning to conserve these areas for the diverse wildlife that they contain.

Suggested Reading:

Mattion, C. 1987. Frogs and toads of the world. Facts on File Publication New York, NY.

Pyrom, J. 1987. Frogs and Toads: a complete introduction.

Web page with: Links on the Red-Eyed Tree Frog