Agalychnis callidryas

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For another species commonly known as the red-eyed tree frog, see Litoria chloris
Red-eyed tree frog
Red eyed tree frog edit2.jpg
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Hylidae
Genus: Agalychnis
Species: A. callidryas
Binomial name
Agalychnis callidryas
(Cope, 1862)

The red-eyed tree frog (Agalychnis callidryas) is an arboreal hylid native to Neotropical rainforests where it ranges from Mexico, through Central America, to Colombia.[1] It is sometimes kept in captivity.

The scientific name of red-eyed tree frog, Agalychnis callidryas, comes from Greek words kallos (beautiful) and Dryas (a tree or wood nymph).[2]

As its name suggests, the red-eyed tree frog has red eyes with vertically narrowed pupils. It has a vibrant green body with yellow and blue vertically striped sides. Its webbed feet and toes are orange or red. The skin on the red-eyed tree frog's stomach is soft and fragile skin, whereas the back is thicker and rougher.

Red-eyed tree frogs have sticky pads on its toes. Phyllomedusine tree frogs are arboreal animals, meaning they spend a majority of their lives in trees; they are excellent jumpers.

Specimen in camouflage mode
A. callidryas at night

Red-eyed tree frogs are not poisonous and rely on camouflage to protect themselves. During the day, they remain motionless, cover their blue sides with their back legs, tuck their bright feet under their stomachs, and shut their red eyes. Thus they appear almost completely green, and well hidden among the foliage. [3]

The large red eyes not only allow identification, but also serve as a defensive adaptation called startle coloration. When a red-eyed tree frog detects an approaching predator, it will abruptly open its eyes and stare at the predator. The sudden appearance of the red eyes, with their bright aposematic coloration and resemblance to the eyes of a dangerous animal such as a cat, triggers a fear instinct in the predator and gives the frog a chance to flee. [3]


Diet[edit]

Red-eyed tree frogs are insectivores that eat crickets, moths, flies, and other insects.

Threats[edit]

The following have been listed as threats to the survival of the species on the IUCN Red List:[1]

  • Residential and commercial development
    • Housing and urban areas
  • Agriculture and aquaculture
    • Annual and perennial nontimber crops
      • Shifting agriculture
      • Small-holder farming
      • Agroindustrial farming
    • Livestock farming and ranching
      • Small-holder grazing, ranching or farming
      • Agroindustrial grazing, ranching or farming
  • Biological resource use
    • Logging and wood harvesting
  • Pollution
    • Agricultural and forestry effluents

Reproduction[edit]

Red-eyed tree frogs in axillary amplexus

During mating season, the male frogs shake the branches where they are sitting to improve their chances of finding a mate by keeping rivals at bay. This is the first evidence that tree-dwelling vertebrates use vibration to communicate.[4] When rainfall is at its highest, a male red-eyed tree frog calls "chack" to get the attention of the female. During amplexus, the female carries the male on her back for up to several hours during the oviposition process. The female chooses a leaf above a pond or large puddle on which to lay her clutch of eggs. She lays around 40 eggs in a clutch. Since oviposition generally occurs on both sides of a leaf, red-eyed tree frogs may fold the leaf to camouflage the eggs against predators and environment. They also produce sticky jelly to adhere eggs together, which can protect the eggs from splitting and dehydration. [5]

The eggs develop into tadpoles, which hatch after six to seven days and fall into the water below.[6] Red-eyed tree frog eggs exhibit phenotypic plasticity and will hatch earlier if a change in the environment, such as a predator or environmental change, signals a danger to their survival.[7] Dragonflies, fish, and water beetles prey on the tadpoles. The tadpoles remain in the water from three weeks to several months, until they metamorphose into frogs. The time metamorphosis emerges depends on duration of larval stage, which varies depending on environment. After metamorphosis, the color of tadpoles' torsos changes from green to brown, and their eyes, which are initially yellow, turn into deep red without too much side patterning. These changes mark the maturity. The lifespan for mature red-eyed tree frogs is about five years. [8]

The young frogs that survive the first few weeks after metamorphosis move into the undergrowth and security of plants near their natal pools, often into the hollows of tubular plants such as bromeliads. Young frogs prey on very small flies and other insects during the first months of their lives. The young mature after two years and begin mating at the age of three to four years. These tree frogs are known to live up to five years (data from captive breeding programs), depending on the health and conditions of their habitat (when aided by abundant plant growth, plenty of fresh water, and an abundance of small and larger insects on which to prey).

They sometimes breed successfully in captivity if kept under adequate conditions in high-humidity vivaria (e.g., by using misting equipment), tropical plants such as Bromelia and other epiphyte plants, together with well-aerated water pools. Their captive habitat should have a light cycle with 11–12 hours of daylight and an average day temperature of 26–28 °C (and night-time averages of 22–35 °C). Simulating a rainy season once a year in November to December will encourage reproduction.

Phenotypic Plasticity[edit]

Red-eyed tree frogs’ embryos exhibit phenotypic plasticity and will hatch earlier in response to disturbance to protect themselves. Though embryos are bred synchronously, they normally hatch after six to ten days from oviposition without disturbance. [5] However, a simultaneously early hatching in entire clutches will be triggered as long as embryos are exposed to their predators or threatening environmental changes such as rainstorm and flood. [5][9] Predators are the major cause that induce the response mechanism of early and rapid hatching. Since red-eyed tree frogs usually breed on both the upside and the underside of leaves above ponds, clutches need to protect themselves against arboreal, aerial and aquatic predators, such as snakes, dragonflies, fish, monkeys and pathogenic fungus. [10] When predators reach a distance close enough to produce detectable vibration, the mechanism will assess disturbance. After a few seconds, embryos vigorously hatch out into tadpoles and spread out to survive. [5][11] Since eggs are usually laid above ponds, tadpoles can have higher probability of survival because they will fall into water after hatching. Even though tadpoles fall on ground, they can survive up to twenty hours without water. [10] However, vibration and disturbance cause by unthreatening environmental changes or other species will not induce early hatching. [9]

Distribution and habitat[edit]

Red-eyed tree frogs inhabit areas near rivers and ponds in rainforests and humid lowlands on the Atlantic slopes from southern Veracruz and northern Oaxaca in Mexico, to central Panama and northern Colombia. They also live on the Pacific slope in southwestern Nicaragua and southwestern Costa Rica to eastern Panama. [10] The optimum temperature for red-eyed tree frogs to survive is 75-85 degree Fahrenheit in the daytime, 66-77 degree Fahrenheit at night. [3]

See also[edit]

References[edit]

  1. ^ a b c Frank Solís, Roberto Ibáñez, Georgina Santos-Barrera, Karl-Heinz Jungfer, Juan Manuel Renjifo & Federico Bolaños (2008). "Agalychnis callidryas". IUCN Red List of Threatened Species. Version 2013.1. International Union for Conservation of Nature. Retrieved October 7, 2013. 
  2. ^ Badger, David P. (1995). Frogs. Stillwater (Minn.): Voyageur Press. p. 64. ISBN 9781610603911. Retrieved 9 May 2015. 
  3. ^ a b c Boman, Bonnie L. "Agalychnis callidryas, Rana-de árbol ojos rojos". Animal Diversity Web. University of Michigan. Retrieved 9 May 2015. 
  4. ^ Caldwell, Michael S.; Johnston, Gregory R.; McDaniel, J. Gregory; Warkentin, Karen M. "Vibrational Signaling in the Agonistic Interactions of Red-Eyed Treefrogs". Current Biology 20 (11): 1012–1017. doi:10.1016/j.cub.2010.03.069. 
  5. ^ a b c d Whittaker, Kellie. "Agalychnis callidryas". AmphibiaWeb. University of California, Berkerley. 
  6. ^ William F. Pyburn (1970). "Breeding behavior of the leaf-frogs Phyllomedusa callidryas and Phyllomedusa dacnicolor in Mexico". Copeia 1970 (2): 209–218. JSTOR 1441643. 
  7. ^ Fields, Helen. (2013 January). The frog that roared. Smithsonian, 54–61.
  8. ^ "Agalychnis callidryas Cope 1862". Amphibians of Panama. Smithsonian Institution. 
  9. ^ a b Caldwell, Janalee P.; Vitt, Laurie J. (Mar 25, 2013). Herpetology: An Introductory Biology of Amphibians and Reptiles. Academic Press. p. 342. ISBN 978-0-12-386919-7. Retrieved 9 May 2015. 
  10. ^ a b c Savage, Jay M. (Aug 1, 2002). The Amphibians and Reptiles of Costa Rica: A Herpetofauna Between Two Continents, Between Two Seas. University of Chicago Press. p. 281. ISBN 0-226-73537-0. Retrieved 9 May 2015. 
  11. ^ Warkentin, Karen M. (Oct 12, 1998). "The development of behavioral defenses: a mechanistic analysis of vulnerability in red-eyed tree frog hatchlings". Behavioral Ecology 10 (3): 251-262. ISSN 1045-2249. Retrieved 9 May 2015. 

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