Adult: Species description based on Ibanez et al (1999), Duellman (2001), and Savage (2002). Moderately-sized green treefrog with very slender arms and legs. Males are smaller than females: males to 56 mm; females to 71 mm. Dorsal: Bright to dark green. The dorsal skin is smooth, but may have one to many slightly raised white spots. Ventral: Creamy white. Ventral surface slightly granular. Concealed surfaces: Concealed portions of the thigh are orange or sometimes blue. Distinguishing characteristics: Agalychnis callidryas has dark blue to purple flanks with vertical bars that range in color from cream to yellow. The width and number of vertical bars varies greatly. Eye: Iris bright red. Pupil vertical. Palpebral membrane has pale to bright yellow reticulations. Extremities: Hands and feet moderately webbed. Toes with large terminal discs. Hands and feet are mostly orange.
Breeding season: The breeding season is largely concordant with the rainy season (Duellman 1970). In Panama, the breeding season lasts roughly from May to November or even January, depending on the duration of the rainy season. Large breeding choruses form at the edges of temporary and permanent ponds, particularly on nights after heavy afternoon rainstorms. Males call from trees and bushes around ponds. It is thought that females ovulate at least twice during the breeding season (Duellman 2001). Egg: Eggs are laid terrestrially on leaves overhanging water. Eggs range in color from white to yellow to green to teal. The jelly surrounding the eggs is clear but quite thick. Typically, multiple clutches of less than 10 to more than 100 eggs are laid by a single female in a night (Duellman 2001). Females must go to the water prior to laying a clutch of eggs to absorb water to hydrate the jelly surrounding the clutch (Pyburn 1970). Eggs become capable of hatching four days post-oviposition, but if undisturbed, embryos typically remain in the egg until the night of age 6 days (Warkentin 1995). Tadpole: Tadpoles develop in ponds where they can easily be dipnetted from the water column. Tadpole bodies are mostly tannish brown to grey or bluish. Caudal fins are transparent, however the tail sometimes develops dark grey pigmentation. Tadpoles typically orient themselves almost vertically, with the head up, in the water column. Agalychnis callidryas tadpoles survive for no more than 20 hours out of water (Valerio 1971). Tadpoles are rather tasteless (Wassersug 1971).Tadpoles are primarily midwater suspension feeders (Satel and Wassersug 1981). However, tadpoles have also been observed feeding on dead conspecifics, fish flakes, and rabbit chow (Hughey pers. obs.). Metamorph juvenile: Metamorphs emerge in as little as four weeks but duration of the larval stage varies considerably depending on pond conditions. Metamorphs range in color from green to brown. The eye is initially yellow and newly emerged metamorphs lack side patterning. Adult coloration becomes apparent within several weeks (Starrett 1960). Time to maturity and lifespan in the wild is unknown.
Habitat: Humid, lowland forest to less than 1000 m (Duellman 1970). Ecology: Adults likely live in the forest canopy. Frogs have been heard calling from high in the trees just as dusk falls, and observed descending to breeding ponds (Duellman 2001). Individuals have been found in palm fronds (Stuart 1958) and bromeliads (Duellman 2001) during the dry season. Egg consumers include snakes (Warkentin 1995, Ryan and Lips 2004), wasps (Warkentin 20001) and a pathogenic fungus (Villa 1979, Warkentin et al. 2000). Monkeys have also been observed eating frog eggs (Hughey pers. obs.). Clutches sometimes become infested with phorid and psychodid fly larvae (Villa 1980). Fly larvae largely subsist on eggs that are already dead, but occasionally attack and kill live embryos of other species of frogs (Villa 1980, Villa and Townsend 1983). If they fall into the water, eggs may be eaten by con- and hetero-specific tadpoles as well as the turtle Kinosternon leucostomum, but not by fish (Roberts 1994). Tadpoles are consumed by a wide variety of vertebrate and invertebrate predators (Touchon and Vonesh pers. comm.). Adults are susceptible to infection by at least 4 species of helminths (Goldberg and Helsey 2008). Because A. callidryas are not as susceptible as other species to chytridiomycosis, they may act as disease reservoirs (Lips et al. 2006). Call: A single or sometimes double "chock". Males produce aggressive chuckles towards other males (Pyburn 1970). Duellman (1970) and Gray and Rand (1970) reported calling activity at daybreak. Karyotype: 2N = 26 (Duellman and Cole 1965, Schmid et al. 1995). Evolotion: Considerable geographic variation in body size, flank coloration and patterning, and leg coloration exists in A. callidryas (Robertson 2008, Robertson and Robertson 2008, Robertson et al. 2009). Patterns of biogeographic diversification differ from those of Dendropsophus ebbraccatus (Robertson et al. 2009). Hatching in response to risk appears to be an ancestral characteristic in phyllomedusines (Gomez-Mestre et al. 2008). The trait was most likely originally a response to flooding, but some species, such as A. callidryas, have evolved to respond to additional risks such as snakes (Gomez-Mestre and Warkentin 2007). Behavior and communication: Eggs hatch prematurely in response to disturbance (Warkentin 1995, Warkentin et al. 2000, Warkentin 2001). Embryos can distinguish between dangerous and benign disturbances based on the vibrational frequencies produced by the disturbance as well as the temporal pattern of the vibrations (Warkentin 2005, Warkentin et al. 2006, Caldwell et al. 2009). Embryos do not hatch immediately upon disturbance. Instead, embryos require time to sample cues; thus, hatching is delayed to until enough information is accrued (Warkentin et al. 2007). Tadpoles also adjust the timing of metamorphosis, emerging smaller in the presence of tadpole predators but later and larger if there are metamorph predators (Vonesh and Warkentin 2006). Males often engage in aggressive interactions, ranging from rapid push-ups to wrestling (Caldwell et al. 2010). Many males will grab onto and try to amplex a female, and multiple paternity sometimes results from multiple male breeding (d'Orgeix and Turner 1995). Amplexus is axillary. For an extensive description of breeding behavior see Pyburn (1964, 1970) and McCranie et al. (2003). Type locality: "Darien, Panama" Physiology: Agalychnis callidryas have very low calling rates (Duellman and Pyles 1983). The trunk muscles of this species (used for calling) have both low enzyme activity (Bevier 1995) and low mitochondrial volume (Ressel 1996) compared to other frogs with higher calling rates. The skin of A. callidryas has low reflectance in visible wavelengths but reflectance is higher in the near infrared (Emerson et al 1990). Testis size larger than average, probably because of multiple male mating in this species (Emerson 1997). Oxygen availability is variable within the egg (Warkentin et al. 2005). Embryos have large external gills, which they position to maximize oxygen consumption (Rogge and Warkentin 2008, Warkentin et al. 2005). Prostaglandins regulate external gill loss of embryos (Warkentin and Wassersug 2001). Diet: Adult diet is unknown. Presumably adults eat small arthropods.