Family Microhylidae

Phrynomantis bifasciatus (Smith, 1847)

Banded Rubber Frog, Red-banded Rubber Frog, Rooiband-rubberpadda (A), Rooiband-gomlastiekpadda (A)

By L.H. du Preez

Currently accepted name: Phrynomantis bifasciatus
Red listing status: Least Concern

Photo by Boyce J.K.; Wian Van Zyl, 2011. URL: FrogMAP: 240

Distribution

This widespread species is distributed from the Democratic Republic of Congo, eastern Ethiopia and Somalia, south through East Africa to northeastern South Africa. Its range extends westward through northern Botswana and northern Namibia to southern Angola.

In the atlas region, P. bifasciatus is recorded from northern KwaZulu-Natal (north of 29°S), Swaziland, eastern Mpumalanga, Limpopo Province, northern Gauteng and the central and northern parts of North West Province (north of 27°S and east of 24°E). Historical records from Durban (2930DD) and Kimberley (2824DB) may have been based on accidentally translocated individuals. No further records were obtained from these areas in the course of the atlas surveys, and the historical records have therefore been omitted from the atlas distribution map.

The atlas distribution data are accurate, but incomplete in some areas such as North West Province.

Habitat

P. bifasciatus inhabits a variety of bushveld vegetation types in the Savanna Biome, at altitudes of 50–1450 m. It appears to be adapted to living in hot, semi-arid environments. Breeding takes place in temporary pans and pools, flooded grassland and small, shallow dams (Wager 1965; Jacobsen 1989; Lambiris 1989a).

Life history

This frog seldom jumps, but walks or runs. When disturbed, it inflates and arches its body, tucking its head in and raising its rump to accentuate the aposematic colours and markings. These frogs may be handled without ill effects, but if unduly alarmed or hurt, they produce copious skin secretions with an unpleasant odour. The secretions are toxic, irritant and lethal to other frogs confined in the same container. They are cardiotoxic, affecting the potassium channels in the membranes of human heart cells, and cause cell death within a short time (Van der Walt et al. 1992). In humans, prolonged skin contact, or assimilation of the toxin via cuts or scratches on the hands, can cause extremely painful swelling and other symptoms such as nausea, headache, respiratory distress and an increased pulse rate.

During the dry season, P. bifasciatus takes shelter under rocks or logs, in holes excavated by other animals, in termitaria, in holes in trees or under loose bark, in the axils of banana leaves and in drain pipes (Pienaar et al. 1976; Wager 1986; Lambiris 1989a). It often shelters with other frogs, lizards, scorpions and whip scorpions (Jacobsen 1989). Although this species is not a true climber, the expanded digits enable it to climb rock surfaces and tree trunks with ease.

P. bifasciatus breeds during spring and summer, after sufficient rain has fallen to produce shallow pools and pans. Males usually call from concealed positions under vegetation or rocks, in holes in trees, the ventilation shafts of termitaria, or from the hoofprints of cattle (pers. obs.), but also from more exposed sites. Males begin to call when they are some distance from the water’s edge, but as the intensity of the chorus increases they move closer to the water, calling from exposed sites at the water’s edge or from emergent or flooded vegetation (L.R. Minter pers. comm). These frogs are opportunistic in that they will breed in the smallest bodies of water. For example, tadpoles have been seen in the water-filled prints of animals such as elephants (Channing 2001).

The eggs are light brown at one pole, 1.3–1.5 mm in diameter, and are surrounded by a jelly capsule that expands from 4 to 7 mm in diameter (Stewart 1967). Clutches of 300–1500 eggs are laid in a mass of jelly, c.75 mm across, that is attached to vegetation or sinks to the bottom of the pool. Tadpoles hatch after four days (Power 1927a).

The tadpoles are gregarious. They resemble Xenopus tadpoles, but lack tentacles and have deeper, pigmented fins (black or red). They are filter-feeders, maintaining their position in the water column by means of a rapidly undulating tail tip. Tadpoles usually reach metamorphosis after about a month, depending on the availability of food (Wager 1986), but may take 90 days in captivity (Power 1926a).

The adults feed mainly on ants, but also consume other Hymenoptera, termites, grasshoppers and spiders (Jacobsen 1982). The Hamerkop Scopus umbretta is reported to prey on this species (Channing 2001).

Conservation

Because of its striking colouration and appearance, P. bifasciatus is well known in the pet trade It was imported into Germany before 1931 (Channing 2001) and is presently offered for sale on the internet. Nevertheless, the species is common throughout its range and occurs in a number of national parks and provincial nature reserves. It is not threatened and no additional conservation measures are needed.

Current distribution map

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