Agalychnis callidryasRana-de árbol ojos rojos

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Geographic Range

Agalychnis callidryas can be found throughout most of Central America, as far north as southern Mexico.

(Abernathy and Abernathy, 1996)

Habitat

Agalychnis callidryas inhabit tropical rainforest areas, where they are commonly found in the lowland rainforests and surrounding hills, particularly in areas close to rivers.

They prefer temperatures between 75-85 degrees during the day, between 66-77 degrees during the nighttime, and humidity at around 80%-100%.

Red-eyed tree frogs are excellent climbers and, as mentioned before, have suction-cup toes that help them attach themselves to the underside of leaves, where they rest during the day. They can also be found clinging to branches, tree trunks, and leaves throughout their habitat. Red-eyed tree frogs are also able to swim.

(Abernathy and Abernathy, 1996)

Physical Description

Agalychnis callidryas are known foremost for their huge, bright red eyes, a possible adaption to nocturnality or the central component of a defensive strategy called startle coloration. Their dorsal area is usually a neon-like shade of green, but can sometimes range from blue to yellow in coloring. The sides are light blue with cream to yellow colored stripes. The upper legs are bright blue, and the feet are a bright orange or red. Agalychnis callidryas have large, specially developed suction cup toe pads, which allow them to attach to leaves, branches, and the sides of trees.

Young A. callidryas start out brown in coloring and change to green as they mature to adult frogs.

Male A. callidryas are generally smaller than the females, the males reaching an adult length of about 2 inches, and the females reaching and adult length of as much as 3 inches.

Adult A. callidryas can change their color to a darker green or reddish-brown as their mood changes.

Development

Reproduction

Agalychnis callidryas usually reproduce in the rainy season. The reproduction process is initiated by a croaking and quivering mating ritual described below. Red-eyed tree frogs utilize a process called amplexus, a common form of reproduction for frog species. In amplexus the smaller male clasps the larger female when her eggs are mature. The male inseminates the eggs as they emerge from the female, and he does not leave until the eggs have been laid. Amplexus may persist for a day or longer.

As reproduction takes place on the underside of leaves, the female must hold on to the underside of the leaf with her suction-cup toes, holding on for both herself and her mate. Each group of eggs that a female produces is called a clutch, and the female must enter the water after laying each clutch, with the male still attached to her back, in order to fill her bladder with water. If the female does not fill her bladder between clutches, her eggs will dry up and die. Sometimes when a female and her mate enter the water, other males see them entering and attempt to force the male from her back. If this is accomplished, another male will take his positon and fertilize the next clutch eggs.

While most frog species lay their eggs directly into the water, A. callidryas lay theirs on the underside of leaves that hang over bodies of water. When the clutches of eggs have developed into tadpoles, which occurs very quickly, the tadpoles swim around within their eggs until the egg ruptures. The rupturing of all the eggs in the clutch occurs within a one minute time period, and the fluid released from the ruptured eggs helps to wash all the tadpoles down the leaf and into the waiting water below. Reproduction is a very strenous activity for A. callidryas.

(Hickman and Roberts,1995, http://www.discovery.com/)

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)

Lifespan/Longevity

  • Average lifespan
    Status: captivity
    4.1 years
    AnAge

Behavior

Some believe that the bright, red eyes of A. callidryas act as a form of defense termed startle coloration. Red-eyed tree frogs are nocturnal and rest during the day. If a predator were to happen upon A. callidryas, the frog would awaken, and its eyes would pop open abruptly. The sudden brightness of their red eyes might startle the predator enough to give A. callidryas the mere seconds necessary for the agile frog to jump to safety.

The musical mating ritual of A. callidryas is begun by the loud croaking of one red-eyed tree frog, who is quickly joined by the other male A. callidryas in the area, all sharing the common goal of attracting females. This loud croaking continues as A. callidryas males jump from one leaf to another in a crazed attempt to establish territory. Male A. callidryas are also known to "quiver" to attract females, but this act has only been seen by a few people. Quivering occurs when the loud croaking is at its climax. Male A. callidryas inflate their vocal cavities and rise on all fours in an attempt to attract females and deter other males from entering their territory. During this process, at least two males face each other and quiver, their bodies violently shaking. This quivering ritual establishes territory and demonstrates strength and intimidation. During this process, when sparked by even the smallest movement, male A. callidryas wrestle with other males, and sometimes many males climb on top of one another. There have even been cases where one frog pinned another down on a leaf. This quivering process has only been observed in the genus Agalychnis. Sometime during this mating ritual, trying not to attract too much attention, the females slowly come down from the treetops. Once the female has been noticed, many different males will jump on her back, fighting each other for the best positioning. The best positioned male is the one who is straight on her back and can clamp his arms and legs around her stomach. Sometimes several males will stay on her back for days until she finds an adequate spot to lay her eggs. Once she is in this spot, all the males attempt to fertilize her eggs.

( http://www.discovery.com/)

Food Habits

Agalychnis callidryas are carnivorous and feed primarily at night. The red-eyed tree frog's green coloring permits it to stay hidden among the leaves of trees, waiting for insects or other small animals to come their way. Agalychnis callidryas eat any type of insect that fits into their mouth, but their usual diet is composed of crickets, moths, flies, grasshoppers, and sometimes even smaller frogs. As babies they feed on fruit flies and pinhead crickets.

(Abernathy and Abernathy, 1996)

Economic Importance for Humans: Positive

Agalychnis callidryas are very popular in the pet trade. Their beautiful coloring makes these frogs very popular among frog and amphibian enthusiasts.

Agalychnis callidryas are also ecologically important. They and other amphibians are generally thought to suffer from environmental effects at an earlier time than other animals and can therefore be used as indicator species to alert humans to environmental changes in their habitat.

Conservation Status

These frogs are not considered threatened in their natural environment. However there has been much concern about the overall condition of the rain forest habitat in which A. callidryas resides. Global warming, deforestation, climatic and atmospheric changes, wetland drainage, and pollution have caused dramatic declines in the amphibian population in, and among the rainforests of Central and South America.

Other Comments

Agalychnis callidryas, a well-known member of the rain forest community, is a popular and identifiable symbol of the movement to save the world's rainforests.

Contributors

Bonnie L. Boman (author), University of Michigan-Ann Arbor.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

References

Abernathy, C. and B. Abernathy. 1996. http://www.geocities.com/abbethy/Red-Eyes.html?977105182600

Hickman, P. and S. Roberts. 1995. Animal Diversity. Wm. C. Brown Publishers, Dubuque.

http://www.discovery.com/