Family Hyperoliidae

Hyperolius marmoratus Rapp, 1842

Painted Reed Frog, Marbled Reed Frog, Geverfde Rietpadda (A), Gestreepte Rietpadda (A)

By P.J. Bishop

Currently accepted name: Hyperolius marmoratus Rapp, 1842
Red listing status: Least Concern (IUCN ver 3.1, 2013)

Photo by Braun K, 2005. URL: FrogMAP: 100

Distribution

This species forms part of a large complex of geographical variants (subspecies), distributed across most of sub-Saharan Africa, which are distinguished from one another by differences in dorsal colour patterns. However, adjacent populations with different colour patterns often intergrade to a greater or lesser extent, while within populations themselves, there is variation in the colour and markings of juveniles and adult males. These factors, combined with a scarcity of behavioural and other data, have resulted in a confused and unresolved taxonomy (Poynton 1964, 1985; Schiøtz 1971, 1975, 1999; Pienaar et al. 1976; Poynton and Broadley 1987; Lambiris 1989a; Passmore and Carruthers 1995; Channing 2001). Ongoing investigation of the ecology, advertisement call structure and genetics of populations from different parts of Africa has already revealed the presence of cryptic species, and is gradually unravelling the systematics and stabilising the taxonomy of this complex (Channing 2001).

Schiøtz (1971, 1999) and Pienaar et al. (1976) assigned H. marmoratus to the superspecies H. viridiflavus, but other authors (Poynton 1985; Poynton and Broadley 1987; Lambiris 1989a; Passmore and Carruthers 1995) continue to recognise H. marmoratus as a separate species composed of a number of subspecies, or a species complex including several subspecies (Channing 2001). The latter approach is adopted here, pending a more thorough taxonomic and systematic revision of the complex.

Channing (2001) listed 13 subspecies of H. marmoratus distributed through sub-Saharan Africa, of which three occur in the atlas region. H. m. taeniatus is distributed from Limpopo Province, Mpumalanga and Swaziland, southward to about St Lucia (2832AD), where it intergrades with H. m. marmoratus (Lambiris 1989a). The latter occurs from St Lucia southward to west of Port Edward (3130AA), while H. m. verrucosus is recorded from the south coast of KwaZulu-Natal, southward along the Eastern Cape coast to Tsitsikamma (3323DD) in the Western Cape (Lambiris 1989a; Passmore and Carruthers 1995). There is currently no evidence to suggest that cryptic species are represented within these subspecies of H. marmoratus.

In recent years, several populations of H. marmoratus have been recorded further west of Tsitsikamma, through Swellendam (3420AB), to the Cape Peninsula (3418AB). While these new records may reflect a natural range extension, it is more likely that they have resulted from accidental or deliberate human-assisted translocations. Also, some of the westerly records in Limpopo, Gauteng and Mpumalanga provinces may be the result of translocations. For example, specimens of H. m. taeniatus have been encountered in consignments of bananas arriving in Cape Town from KwaZulu-Natal or Mpumalanga (A. de Villiers pers. comm.) and have been found in Pretoria on nursery plants originating from KwaZulu-Natal. A well-established population in Tokai on the Cape Peninsula (3418AB) is likely to have originated from such translocated animals.

This species has a loud, distinctive call and forms large choruses that are active for an extended period during the breeding season. The atlas data are reasonably complete and reliable.

Habitat

H. marmoratus inhabits a variety of vegetation types within the Savanna, Grassland and Forest biomes, and occurs marginally in the Fynbos Biome. It is a widespread and abundant species along the coast and at low altitudes east of the Great Escarpment in Limpopo Province, Mpumalanga and Swaziland. However, large breeding populations are also recorded at higher elevations, e.g., 1300 m at Ixopo (3030AA) in the KwaZulu-Natal Midlands, and 1400 m at Haenertsburg (2329DD) in Limpopo Province. Jacobsen (1989) recorded this species in montane grassland at 1600 m.

H. marmoratus utilizes a wide variety of breeding sites, ranging from temporary ponds, pans and vleis, to permanent bodies of water such as dams, marshes, reedbeds, sluggish rivers and streams (Pienaar et al. 1976; Poynton and Broadley 1987; Lambiris 1989a; Channing 2001).

Life history

The adults aestivate during the dry season, and have been found sheltering some distance from their breeding sites in vegetation or under logs and stones. During this time they often take up residence inside houses, where they conceal themselves behind cupboards, pelmets, pictures and in toilet cisterns. The breeding behaviour of this species is arguably the best documented for any African frog, with more than 15 papers and numerous theses relating to the subject published within the last decade.

Although males will call after rain at any time of the year, breeding normally takes place October–February. At low altitudes male calling behaviour is inhibited by temperatures <16°C, while at higher altitudes breeding has been observed at temperatures <10°C (pers. obs.).

Before dawn, breeding adults usually move into the canopy of surrounding trees or bask in the sun on emergent vegetation at the edge of the breeding site (pers. obs.). At dusk they descend to the water body where males take up specific call sites (to which they return on consecutive nights) and call consistently from dusk to just after midnight. Males occasionally call from their resting places in tree canopies in the late afternoon. Where present, tall emergent plants such as reeds and sedges (e.g., Eleocharis limosa, Cyperus papyrus and Typha capensis) are favoured as call sites, but males will also call from trees, grasses, bushes, floating vegetation or even bare soil at the water’s edge (L.R. Minter pers. comm.; pers. obs.).

On average, males call for only a few nights in a row, returning to the breeding chorus after a period of about 10 days (Dyson et al. 1992). Gravid females enter the pond shortly after dusk and usually select a mate within a few hours. After several hours in axillary amplexus, the eggs are laid in water. Females have been observed to lay more than one clutch of eggs per season with a month-long interval between layings (pers. obs.). From 150 to 650 eggs are laid in flattened clumps of c.20, on the surface of submerged leaves, stalks or stones, or amongst the roots of aquatic plants (Pienaar et al. 1976; Channing 2001). Tadpoles hatch within five days and metamorphosis takes 6–8 weeks (Pienaar et al. 1967). Males reach sexual maturity at approximately one year (A. Turner pers. comm.)

Predators include various birds, snakes, young crocodiles, terrapins, spiders and other frogs, while prey consists mainly of insects (Channing 2001; pers. obs.).

Conservation

The major threat to this species is habitat loss through drainage of wetlands and afforestation. In several areas in KwaZulu-Natal, the establishment of exotic Eucalyptus plantations has lowered the water table to such a degree that many pans within the coastal dune forest have completely disappeared (pers. obs.).

H. marmoratus is widespread and locally abundant, and populations often consist of hundreds or even thousands of individuals. Atlas data indicate that the range of the species may be expanding. The species occurs in several national parks and numerous provincial nature reserves and therefore does not require additional conservation attention.

Current distribution map

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