Family Bufonidae

Capensibufo tradouwi (Hewitt, 1926)

Tradouw Mountain Toad, Tradouw Toadlet, Tradouw’s Toad, Tradouw Bergskurwepadda (A)

By R.C. Boycott

Currently accepted name: Capensibufo tradouwi
Red listing status: Least Concern

Photo by SCHUTTE THEUNIS; Belinda Nortje, 2014. URL: FrogMAP: 2113

Distribution

C. tradouwi is endemic to the Cape fold mountains in the southwest and south of Western Cape Province (Grandison 1980), with the most easterly locality marginally entering Eastern Cape Province at Misgund (3323CD) in the Tsitsikamma Mountains. The species occurs north and east of the Berg and Breede river valleys, from the Matsikammaberg (3118DD) near Vanrhynsdorp in the north, southward to the Hex River Mountains, and eastward along the Langeberg mountain range to the Outeniqua, Swartberg and Kammanassie ranges. The species is recorded at altitudes of 1000–1600 m.

The atlas data are accurate but incomplete.

Habitat

C. tradouwi occurs at high altitudes in mountainous terrain where it inhabits Mountain Fynbos and Grassy Fynbos. Most of its range lies within the western winter-rainfall region, but in the east extends into the zone of transition to summer rainfall.

Breeding takes place on mountain slopes and valley bottoms in shallow pools in seepage areas, moist depressions, vleis and slow streams. A breeding site on the slopes of Matroosberg in the Hex River Mountains consisted of rock pools varying in depth from a few to several centimetres, in a large expanse of exposed bedrock above a waterfall. Clumps of reeds and grass growing in the cracks provided limited shade to the pools that, in most cases, were on the bedrock and exposed to direct sunlight (pers obs).

Life history

During the day, adults shelter under rocks but may also be found in the open near seepage areas. Diurnal activity is especially common during the breeding season, June–September, when males are often found walking about at the breeding site. A number of tadpoles, found in rock pools at Matroosberg toward the end of October 1982, had hindlimbs, indicating that spawning had taken place in September, assuming that C. tradouwi has a developmental period similar to C. rosei, that is, 25–30 days (pers. obs.). At the end of October, the toads were common at the Matroosberg locality, with >20 specimens seen over a two-day period. They were found under stones lying on bedrock in seepage areas, and even on the high, dry slopes. A somewhat later breeding period was recorded at the eastern-most locality in the Tsitsikamma Mountains. Here males were observed calling in late November 1993, in close proximity to small pools containing tadpoles (M. Burger pers. comm.).

The males call from the edge of shallow pools, often from concealed positions (Channing 2001). Amplexus is axillary. The eggs are unusual in that they are laid singly; in most bufonids, including C. rosei, they are laid in strings. The clutch size is c.60 eggs which are 2 mm in diameter and black at one pole (Channing 2001).

The tadpoles are dark, with unusually long undulating tails, and are benthic in habit (Passmore and Carruthers 1995). At the Matroosberg site, small black tadpoles were densely packed in the pools in plain sight. In some of the larger pools in the bedrock, as many as 100 tadpoles were found, while in the smallest pools, several tadpoles were present. Tadpoles were also found sheltering under small rocks that were lying in some of the pools.

Conservation

C. tradouwi has a wide distribution in the southwestern and southern parts of Western Cape Province, in remote mountainous areas. It occurs in a number of protected areas, including Cederberg Wilderness Area, Grootvadersbosch Nature Reserve and Formosa Conservation Area, and does not appear to be threatened. Nevertheless, there have been few recent observations of C. tradouwi, and it is recommended that surveys be undertaken to confirm its current status.

Current distribution map

Undated records;  pre-1996;  1996 to 2002;  2003 to present