Limnodynastes dumerilii is a frog species from the family Limnodynastidae. The informal names for the species and its subspecies include eastern or southern banjo frog, and bull frog. The frog is also called the pobblebonk after its distinctive "bonk" call, which is likened to a banjo string being plucked. There are five subspecies of L. dumerilii, each with different skin coloration. The species is native to eastern Australia. There has been one occurrence in New Zealand, when tadpoles of the species were found in 1999 and destroyed.
Adults are roughly seven to eight centimetres long with dark warty backs, a prominent tibial gland, fleshy metatarsal tubercules and a smooth white or mottled belly. The tadpole stage is relatively long, lasting up to fifteen months. The species is common. The five subspecies of Limnodynastes dumerilii are:
Eastern banjo frog, Limnodynastes dumerilii dumerilii
This is the most widespread of the five subspecies. It is mostly associated with the slopes and ranges of New South Wales, northern Victoria and the Murray River into South Australia. This subspecies normally inhabits woodland, heathland and farmland. Breeding takes place in streams, ponds and dams. Males of this subspecies have the most characteristic banjo-like "bonk" of all the subspecies. They are distinguished from other subspecies by more orange present on the flank and orange raised stripe present from the eye to the shoulder. The subspecies is normally one solid colour on the dorsal surface.
Eastern banjo frog, Limnodynastes dumerilii grayi
This subspecies occurs along the coast of New South Wales, south to Jervis Bay. It inhabits coastal swamps, dams, ponds associated with forest and heathland. This species does not breed in flowing water, which helps with distinguishing it from L. d. dumerilii in places where both occur. This is the most variegated of the subspecies, often with patches or blotches of a different colour on the dorsal surface. The call of this species sounds more like a "tok", similar but louder than the striped marsh frog.
Snowy Mountains banjo frog, Limnodynastes dumerilii fryi
This is the most restricted of the subspecies. It is only found in the Snowy Mountains area of south-eastern New South Wales. Males call from ponds or pools of streams in spring and summer. Due to its restricted range it is unlikely to be confused with other subspecies, however it is pale on the dorsal surface with fairly indistinct patches or variegations.
Southern banjo frog, Limnodynastes dumerilii insularis
This subspecies occurs south of Jervis Bay, along the south coast of New South Wales, in eastern Victoria and throughout Tasmania. It is characterised and distinguished by blue coloration present on the flank. There is often a pale mid-dorsal stripe. Males call from a concealed position in water during spring, summer and autumn.
Southern banjo frog, Limnodynastes dumerilii variegata
This subspecies is very similar to Limnodynastes dumerilii insularis. This subspecies occurs in western Victoria and south-eastern South Australia. It is chiefly distinguished by range.
Ecology and behaviour
Limnodynastes dumerilii is a burrowing frog. During dry times, and often just during the day, they will burrow underground. They will often be seen in large numbers after rain, and under the right conditions mass spawning can occur over just a few days. They have been known to call while underground, and can do so at any time of the year after rain.
- Hero, Jean-Marc; et al. (2004). "Limnodynastes dumerilii". IUCN Red List of Threatened Species. 2004: e.T41159A10407072. doi:10.2305/IUCN.UK.2004.RLTS.T41159A10407072.en.
- Frost, Darrel R. (2018). "Limnodynastes dumerilii Peters, 1863". Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved 26 June 2018.
- Waite, Edgar R. (1929): The reptiles and amphibians of South Australia. Facsimile Edition, issued to commemorate the Second World Congress of Herpetology, Adelaide, South Australia, by the Society for the Study of Amphibians and Reptiles. 1993.
- Brandle, Robert (2001). "A Biological Survey of the Flinders Ranges, South Australia 1997-1999" (PDF). Biodiversity Survey and Monitoring, National Parks and Wildlife, South Australia, Department for Environment and Heritage. Retrieved 26 June 2018.
- Ryan, Paddy (13 July 2012). "Frogs - Threats and conservation". Te Ara - the Encyclopedia of New Zealand. Retrieved 24 January 2015.
- Whitaker, Tony; Bejakovich, Davor (June 2000). "Exotic frog incursion" (PDF). Surveillance. Wellington: Ministry of Agriculture and Forestry. 27 (2): 12–14. Retrieved 22 January 2015.