Amietophrynus pantherinus (Smith, 1828)
Original Published Description:
Panther Toad (English), Cape Toad (English), Southern Panther Toad (English), Western Leopard Toad (English), August Frog (English), Leopard Toad (English)
B. pantherinus is endemic to the winter-rainfall region of the Western Cape. It has a restricted distribution range that spans a distance of about 140 km, from the Cape Peninsula in the west, eastward to beyond Gansbaai in the Pearly Beach area (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
The name is from the Latin pantherinus, meaning "pertaining to the panther," an allusion to the color pattern of this species.
B. pantherinus attains a length of about 140 mm (Text from ).
The dorsum of this species is bright yellow with chocolate-brown patches and includes a yellow vertebral stripe.The ventrum is granular and cream coloured, and the throat of males is dark (Minter et al., 2004, © SI/MAB Biodiversity Program).
The beautiful dorsal pattern of chocolate-brown patches on bright yellow background, with a yellow vertebral stripe, distinguishes this species from the partially sympatric B. rangeri that has generally dull brown dorsal markings, and B. angusticeps that, in this area, has a greyish dorsal surface covered in dark brown blotches, and yellow colouring on the upper surfaces of its feet (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Habitat and Ecology
The species has a distinctly coastal distribution and is generally associated with low-lying areas within about 10 km of the sea. Its distribution correlates with large wetland areas, including rivers, and an annual rainfall of ≥ 600 mm. B. pantherinus is mainly associated with sandy coastal
lowlands but, in places, can also be found in valleys and on the lower mountain slopes and hills near the coast. It is a wide-ranging species and, although it seems to spend most of its time away from water, this toad is always found in the general vicinity of wetland habitats such as rivers, coastal lakes, vleis and pans. (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
This species generally breeds in permanent water bodies but also in seasonal wetlands that retain their water well into the summer months. Breeding habitat includes coastal lakes, vleis, pans, dams, ponds and sluggish, meandering rivers that have stretches of relatively deep, still water. Typical breeding sites have standing open water >50 cm deep, with scattered patches of aquatic plants and beds of emergent vegetation such as bulrushes Typha capensis (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
B. pantherinus is an explosive breeder with a short, defined breeding season (Cherry 1992). Breeding usually takes place during August but has also been recorded at the end of July and in September. At the commencement of the breeding season, large numbers of adults appear and converge on selected breeding sites, hence the old popular name, “August frog”. For example,
after dark on 23 July 1978, 66 adults were counted within c.20 min on a 3-km stretch of road near Noordhoek on the Cape Peninsula. At prime breeding sites, advertisement calls of males can be heard in choruses of up to c.30 individuals, but in urban environments far fewer individuals are usually heard. Calling is most intense at night but is sometimes heard during the day. Males call from stands of emergent vegetation (e.g. bulrushes), but at night, areas of open water are also utilized. The males have a habit of calling from a floating position with limbs outstretched. Amplexing pairs tend to utilize areas of open water for spawning (Cherry 1992). The females deposit thousands of eggs in gelatinous strings. On one occasion a pair was reported to have produced 24 476 eggs (Rose 1929; Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
The advertisement call, a deep, pulsed snore that continues for about a second and is repeated every three to four seconds, easily distinguishes B. pantherinus from all other sympatric toad species. While the advertisement call of B. pardalis (in the Eastern Cape) has been described (Passmore 1977b), an adequate comparison of the calls of B. pardalis and B. pantherinus has not been published (Poynton and Lambiris 1998). Thus the taxonomic status of the two populations has not been fully resolved (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Metamorphosis is fairly slow, taking >10 weeks (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
The relatively small, dark, benthic tadpoles develop into tiny 11-mm long toadlets that leave the water in October–December in their thousands. Relatively few of the offspring develop into adults: most fall victim to a variety of predators (including their own kind) and other hazards (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
IUCN Red List Category and Justification of Conservation Status
There appears to be no obvious decline in the extent of occurrence of B. pantherinus. However, urban development has resulted in permanent loss of habitat and the fragmentation of populations, especially on the Cape Peninsula and Cape Flats. In other areas, habitat degradation has affected habitat quality and led to a decline in population numbers (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
B. pantherinus is threatened throughout most of its range by general development and habitat degradation. While breeding generally takes place in larger, more secure wetlands, urban development poses an obvious threat around these wetlands by causing habitat fragmentation and restricting the foraging area and movement of toads. This results in reduced population size and restricted or completely interrupted gene flow between populations (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
In the urban environment, toads are forced to negotiate roads and barriers (e.g., walls, embankments,canals) while foraging and migrating to and from breeding sites. Expanding urban development and increased road traffic results in the death of hundreds of toads each year, especially during the breeding season. Artificial water bodies with steep vertical sides, such as canalized rivers and swimming pools, represent additional deathtraps that pose a threat to local populations. For example, >3000 newly metamorphosed toadlets were rescued from a Bergvliet domestic swimming pool over a 10-day period, and many more died in the same pool (J.A. Harrison and C.D. Gray pers. comm.; (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
At certain breeding sites on the Cape Peninsula and the Cape Flats, specific threats include pollutants, introduced predatory fish (e.g. barbel), and invasive floating plants (e.g., water hyacinth). In 1999, a well-meaning member of the public “rescued” several specimens of B. pardalis and B. rangeri from roads near Grahamstown in the Eastern Cape, and released them in Constantia, Cape Peninsula (M. Burger pers. comm.). This misguided act may have brought about hybridization between B. pardalis and B. pantherinus, thereby undermining genetic differences between the two taxa. Such translocations may be common occurrences and pose a real threat to the conservation
of genetic diversity (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Conservation Actions and Management
Although this toad occurs in some of the protected nature areas within its range, these generally lack suitable breeding habitat. In fact, most of the protected areas in the southwestern Western Cape Province are located in montane areas, while probably >80% of B. pantherinus breeding habitat is situated lower down in unprotected areas. Zandvlei Nature Reserve (including
the adjoining Westlake Wetland Conservation Area) is one protected area with good breeding habitat. Other statutory conservation areas that provide breeding habitat include Rondevlei and Zeekoevlei nature reserves and Cape of Good Hope Nature Reserve (northern limits), but the quality of this habitat is unknown (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
- Bufo pantherinus Smith, 1828 (synonym)
- Bufo cruciger Schmidt, 1846 (synonym)
- Amietophrynus pantherinus — Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, 2006 (synonym)