Costa Rica Brook Frog

The dorsal coloration is a uniform "leaf-green," the throat and belly are bright yellow, and the ventral side of the limbs is dull yellow (Savage and Heyer 1968). The dorsal thigh surface appears dull yellow or apricot colored, and there are no melanophores except under toe digits III, IV, V. A yellow-white stripe extends from the upper lip to the groin, a bright white stripe runs over the anus, and white stripes run over the arm, and from foot to heel. The dorsum, chin, chest and underarm are smooth, and the belly and ventral thigh are granular. The iris is bright red and the pupil is horizontal. The tympanum is 3/5 to 4/5 the size of the eye. The snout is rounded in profile and truncate in dorsal outline (Savage and Heyer 1968). Fingers are approximately one third webbed (vestigal between fingers I and II), toes are about two thirds webbed, and both toes and fingers bear moderate sized discs (Duellman 1970). Warts are present along the heel stripe, often formed into a small flap, and the prepollex does not protrude (Savage and Heyer 1968). Females are as much as 3 mm larger than males, and tend to have a slightly larger tympanum. Males have a single, internal vocal sac and tan nuptial asperities on the thumb (Savage and Heyer 1968). Tadpole morphology is used as a diagnostic for the genus Duellmanohyla, particularly the huge pendant mouths with 2/2-3/3 short tooth rows (Campbell and Smith 1992).Hyla uranochroa was taxonomically revised by Campbell and Smith (1992) and placed within a new genus as Duellmanohyla uranochroa. The species is also considered to be synonymous to original descriptions of the treefrog Hyla alleei (Duellman 1970).A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio) (http://darnis.inbio.ac.cr/FMPro?-DB=UBIpub.fp3&-lay=WebAll&-Format=/ubi/detail.html&-Op=bw&id=4209&-Find).

Duellmanohyla uranochroa is found from the Caribbean slopes of the Provincia de Bocas del Toro, Panama, into Costa Rica, on the Atlantic and Pacific slopes of the Cordilleras de Tilaran, Central and Talamanca (Savage and Heyer 1968). The distribution zone reaches as high as 1750 meters and descends to about 1400 m on the Pacific side, and as low as 600 m on the wetter Atlantic/Caribbean slopes (Duellman 1970). The habitat has been categorized in the subtropical life zone according to the criteria of Holdridge (1967).

D. uranochroa is active during the night, where individuals are found congregating along montane streams, and during the day they are often found secreted in bromeliads. Breeding activity peaks around May and June, with males calling from dense vegetation several meters from the stream. The mating call has been described as a series of bell-like notes "boop-boop-boop-boop," which may differ individually or geographically in repetition rate and duration. Eggs are oviposited in quiet, silt-bottomed pools (Duellman 1970).

Declines and local extinctions have been reported for populations (referred to as Hyla uranochroa) within the Monteverde region of Costa Rica's Cordillera de Tilaran, synchronous with the decline of 24 (from a total of 53) other amphibian species during 1990 (Pounds et al. 1997). Documentation through 1994 showed limited recovery and recolonization of only 2 of the previous 6 occupied sites (Pounds and Crump 1994).