Tree Frog, Red-Eyed


Agalychnis callidryas  


Male adult length: 2 – 2.5 in. (5.08 – 6.35 cm); female adult length: 2.5 – 3 in. (6.35 – 7.62 cm); coloration: red eyes with a vertical slit pupil, a vertically narrowed noses, a vibrant green body with yellow and blue striped sides, and orange toes. There is a great deal of regional variation in flank and thigh coloration. Young frogs are typically brown in color and turn greener as they mature, although adult frogs can change their color slightly depending on mood and environment.

Family

Hylidae

Order

Anura

Class

Amphibia

Range

Central America: Belize, Colombia, Costa Rica, Guatemala, Honduras, Mexico, Nicaragua, and Panama

Habitat

Near ponds and rivers of tropical lowland and montane rain forests

Life Expectancy

Up to 5 years

Sexual Maturity

2 – 3 years

Diet

In the wild, they eat crickets, moths, flies, and other insects; in the Zoo, they are fed crickets, fruit flies and other invertebrates.

Status

IUCN – Least Concern; CITES – Appendix II

Behaviors

The red-eyed tree frog is nocturnally active. It is arboreal and shelters on the underside of a broad leaf during the day and during the dry season, with limbs folded underneath its body. It has also been found in bromeliads, though this appears to be rare. In suitable habitat, this species is abundant. Red-eyed tree frogs are not poisonous and rely on camouflage to protect them. During the day, they remain motionless, cover their blue sides with their back legs, tuck their bright feet under their belly, and shut their red eyes. Thus, they appear almost completely green, and well hidden among the foliage. Some new research has found that during mating season, the male frogs shake the branches they’re sitting on to improve their chances of finding a mate. This branch shaking actually keeps rivals at bay. This is the first evidence that tree-dwelling vertebrates use vibration to communicate. Some frogs communicate by croaking deep sounds for warnings and high sounds for mating. Breeding occurs during the wet season (late May to November), beginning with the first rains. Mating takes place throughout the rainy season but is particularly frequent in June, and occasionally peaks again in October. Red-eyed tree frogs generally prefer quiet pools of water with overhanging vegetation as breeding sites; the pools may be permanent, seasonal but long-lasting, or temporary. Males make aggressive calls, to deter other males from intruding onto their territories, and advertisement calls, to attract females. The aggressive call sounds like a soft chuckle, and the advertisement call is a “chack” or “chack-chack”, repeated at intervals of 8-60 seconds. Calling begins at dusk and is most frequent in the evening, especially during rains, as males advertise for mates. However, they have also been reported to participate in a brief daybreak chorus of advertisement calls, at a much higher call rate than evening or morning advertisement choruses. On dry nights, males call from higher perches in the tree canopy as opposed to wetter nights or when the ponds are full when they begin calling from the ground and from small trees and bushes near the edges of ponds or backwaters. Calls are generally made from horizontal perches on leaves or branches, although vertical perches on stems are occasionally used. They move about frequently while calling, changing both their positions and the direction of calling. If precipitation or water level conditions are sufficient, males then descend to the breeding sites at the water’s edge and continue calling. Females descend from the canopy, approach selected calling males in a straight line, and allow amplexus to take place. Descent generally occurs slowly hand-over-hand, but parachuting has also been observed in this species, both in the wild and in experimental trials. Once amplexed, a female will carry the male into the water and remain there for about ten minutes. Pyburn (1970) carried out experiments showing that the purpose of this behavior is to allow the female to absorb water through her skin, into her bladder, in order to make the jelly mass surrounding the clutch of eggs. The pair then moves up into the trees, as the female searches for an appropriate egg deposition site on vegetation overhanging the water. Eggs are generally deposited on either the upper side or lower side of a broad leaf, as high as 12 feet over the water. Sturdy plants and trees at the water’s edge are preferred, but oviposition may also take place on emergent vegetation. Egg clutches may also occasionally be deposited on substrates such as branches or fence wire. Very rarely eggs will be deposited on the ground.

Adaptions

Young froglets (at least from Panama) are able to change color; they are green by day and change to purplish or reddish brown at night. Red-eyed tree frogs are excellent climbers and 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 despite not having much webbing between their toes. 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.

Special Interests

Red-eyed tree frogs are closely related to Chorus Frogs (genus Pseudacris), which have the same body style and many of the same habits, though chorus frog are more vocal. Young froglets have yellow rather than red eyes, and have lighter-colored flanks lacking whitish bars. The red eye coloration appears first at the periphery of the eye at about two weeks post-metamorphosis, and over a period of several days spreads inward to make the iris wholly red. They prefer temperatures between 75 - 85°F degrees during the day, between 66 - 77°F during the nighttime, and humidity at around 80%-100%. The species name callidryas is derived from the Greek words kallos, meaning “beautiful”, and dryas meaning “tree nymph” hence the ever appropriate name: beautiful tree nymph.

Folklore

Conservation

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 they reside. Climate change, deforestation, atmospheric changes, wetland drainage, and pollution have caused dramatic declines in the amphibian population in and among the rain forests of Central and South America. It is listed as Least Concern in view of its wide distribution, tolerance of a degree of habitat modification, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category. This species is threatened by habitat loss by the destruction of natural forests although it is known to survive in places with a degree of anthropogenic alteration. It is also recorded within the pet trade. Why do zoos keep this animal? Neotropical frogs are threatened by habitat destruction, disease and other factors. Zoos and aquariums keeping these species want to build up reserve populations and to raise awareness of the global amphibian crisis. Due to its red eyes and the bright colors of its skin, Agalychnis callidryas is particularly suitable for this purpose. Several zoos have also linked their ex situ activities with involvement in situ conservation.

Jacksonville Zoo History

This species first arrived in our animal collection in 2008. We have bred this species.

Exhibit

Range of the Jaguar