Adult: Species description based on Ibanez et al (1999) and Duellman (2001). Large, tan to grey treefrogs, with some mottling on the dorsal surface. Thighs with variable darker grey to brown bars. Males and females are similarly sized. Males to 92 mm; females to 95 mm. Males have large thumb spines that are typically covered by a sheath of skin when not in use. Excellent photos of the sheath and spine can be found in Hobel (2008) and Kluge (1981), respectively. An extensive description of the adults acan be found in Duellman (1970) and Duellman (2001). Dorsal: The dorsal skin ranges from smooth to bumpy. Many specimens have a dark, narrow middorsal stripe. Ventral: Ventral surface cream-colored to slightly bluish and granular. Males sometimes have pigmentation on the throat. Concealed surfaces: Sides often have a number of darker vertical bars, particularly in the area closest to the thigh. Eye: Iris yellowish or light tan above to grey below. Pupil horizontal. Extremities: Hands and feet extensively webbed. Webbing ranges in color from brownish-yellow to orange. Toes with large terminal discs.
Breeding season: Breeding is more common during the rainy season (May-November; Kluge 1981, Fouquette 1966); however, males can be heard calling throughout the year. In the Darien, frogs breed during the dry season (Breder 1946). Males call singly or in small loose choruses near marshes, ponds and streams (Kluge 1981). For females, time between reproductive bouts averages 35.8 days, although some females require over 100 days to yolk up a new clutch (Kluge 1981). Egg: Eggs are laid in shallow, mud nests near the edges of streams (Breder 1946, Kluge 1981), which most likely functions to protect them from con- and heterospecific tadpole predators (Heyer et al 1975, Kluge 1981). The small, black eggs are laid as a surface film. Eggs hatch into small black tadpoles starting 40 hours after oviposition (Kluge 1981). Tadpole: Tadpoles develop in streams or ponds. In larger tadpoles, the body is dark brown and the tail has numerous dark flecks and blotches. The ventral surface is lighter brown. For an extensive description of the tadpole, see Breder (1946). Tadpoles are not distasteful to humans and thus most likely contain few toxic compounds in their skin (Wassersug 1971). Metamorph juvenile: Metamorphosis generally occurs in approximately 40 days (Kluge 1981). Metamorphs are pale green-grey with numerous small dark spots covering the dorsal surface (Kluge 1981, Hobel 2008). Time to maturity is about 1 year (Kluge 1981). Most adults do not survive more than one breeding season (Kluge 1981).