Johnstone's Whistling Frog

Description:

A small, dull-colored frog, adult males are 17-25 mm long and adult females, 17-35 mm. Brown to gray tan dorsal ground color with usually one or two darker chevrons. Often a narrow middorsal pinstripe or a broad pair of dorsal stripes. Marbled, stippled, or blotched on a dark brown to gray tan ground posterior thigh surface and creamy undersurface. Iris gold above and brownish below. Smooth to slightly tuberculate dorsum; head a little broader than long; snout truncate from above; large eyes with eyelids that have many low, rounded tubercles. Distinct tympanum; oblique vomerine odontophores. Distinct, small, rounded finger and toe disks; lacks digital webbing. Many small plantar tubercles; elongate inner metatarsal tubercle larger than conical outer metatarsal tubercle; lacks tarsal fold. Adult males have paired vocal slits and a distensible internal subgular vocal sac strongly granular when uninflated; lacks nuptial thumb pads.

Habitat:

Our garden, Los Palos Grandes, Altamira, Caracas, Venezuela. At the foot of the Cerro del Avila. 1000m above sea level.

Notes:

Call: Two-note whistle that can be repeated at a maximum of 60 times per minute. First note, frequency about 2 kHz for 70-90 milliseconds. Longer second note, lasting 180-270 milliseconds, that rises sharply from about 3 to 4 kHz. Average interval between calls is 1.2 seconds. Oviposition calls are identical to diurnal retreat calls, but are different from lead away calls of initial courtship by duration and frequency.