Size Adult females may reach a length of 31 mm but males are smaller.
Description This frog has a squat, rotund body with a short, narrow head which has a moderately sized eye, horizontally elliptical pupil, hidden tympanum, flat face and narrow mouth. The limbs are short and stumpy (shorter than the body width) and the fingers and toes lack webbing and adhesive discs. The palm of the hand has prominent tubercles and the basal subarticular tubercles are single. The inner and outer toes are as long (or are not noticeably longer) as they are wide. The upper and lower body surface has a rough texture (like sandpaper). The colour on the upper side is of variable shades of brown and/or grey, with light patches running down the back that are fused into a scalloped band with ridged edges. There is a dark streak running from the eye to the region of the arm. The underside colouring is light brown or grey with scattered dark flecks but the throat area is generally dark. The advertisement call is a brief whistle which may be regularly repeated.
Biology This montane species occurs on the tops and slopes of mountains. It is endemic to the Fynbos Biome and although it is generally associated with Mountain Fynbos vegetation, has also been found in altered habitats such as pine plantations. The Cape mountain rain frog is a burrowing species that does not inhabit water. When disturbed, these frogs have the ability to inflate their bodies dramatically as a defence mechanism to deter predators.
Little is known about the breeding of this species. It calls, both day and night, mainly in winter and spring, but has also been recorded calling in January. These advertisement calls of the males are generally associated with damp conditions caused by rain or heavy mist. Besides calling from ground level positions, breeding males also call from elevated positions in vegetation. Although it has not been witnessed in this species, the formation of mating pairs takes place on the surface of the ground, and while in amplexus, the frogs bury themselves backwards into the soil. The eggs are laid in an underground nest and metamorphosis takes place inside the egg capsules with the young emerging as fully formed froglets.
Distribution The Cape mountain rain frog is endemic to the Western Cape Province within which it has a relatively wide distribution. This extends through the Cape Fold Mountains from the Cederberg area in the northwest to the Outeniqua Mountains (above Knysna) in the southeast, and also includes the Cape Peninsula Mountains.
Distribution in GCBC This is situated in the Cederberg Mountains and extends southwards into the Groot Winterhoek Mountains.
Conservation status Not threatened.
Threats No serious threats.
Current studies This species was assessed in the Southern African Frog Atlas Project (published in 2004).