ClimateWatch

An initiative of Earthwatch Institute

  1. 32 Southern Bullfrog Photo by Ross Knowles

Southern Bullfrog, Eastern Banjo, Eastern Pobblebonk Frog

Limnodynastes dumerilii

Appearance

  • Colour: its back ranges from grey, to olive-green, dark brown or black, with dark marbling or flecks. It has a pale yellow stripe running from under its eye to its arm, a dark band above this, and may also have a pale stripe running down its back. Its sides commonly have a purple or bronze sheen, mottled with black. Its belly is white and sometimes mottled with grey. Its back is warty and rough but its belly is smooth.
  • Distinctive feature: a prominent gland on the outer side of its hind leg (its shin) and a fleshy lump at the base of each hind foot.
  • Size: 5 cm to 8.5 cm. 

Behaviour

  • Call: males call when in water and concealed by floating vegetation, or less commonly from the water’s edge. When one frog starts to call, others will often join in. Their call is a single “bonk” or “plonk” which sounds like the string of a banjo being plucked, and is usually repeated every few seconds. Some individuals will produce a rapid series of “bonk-bonk-bonk”.
  • Diet: small invertebrates, for example flies and other small insects.
  • Movement: during dry periods it burrows into the ground and waits for rain, after which it emerges to feed and breed.
  • Breeding: males call to attract females from August though to April, most intensely after heavy rain. Females lay their eggs in a floating foam of bubbles (often attached to and concealed in vegetation) in the still waters of swamps, streams, dams and ponds.

What to Observe

  • Calling
  • Courting / mating
  • The appearance of eggs

ClimateWatch Science Advisor

We expect frogs to start calling and laying eggs earlier in the year as a result of climate change warming the Earth. They may also start appearing in new areas as warmer temperatures enable them to live in environments that were previously too cold for them. 

When To Look

  • From August through to April (breeding season).
  • Listen for males calling at night, particularly after rain. 

Where To Look

  • In south-eastern Australia, including southern Queensland, eastern and southern New South Wales, south-eastern South Australia, Victoria and Tasmania. 
  • In a wide range of habitats near still water, including woodlands, rainforests, farmlands and grasslands, but not in alpine areas or extremely arid zones. It is common in urban areas around garden ponds.

Eastern Banjo Frog Occurrence Map ALA

References

Barker, J, Grigg, GC and Tyler, MJ 1995. A Field Guide to Australian Frogs. Surrey Beatty & Sons, Sydney.

Cogger, HG 2000. Reptiles and Amphibians of Australia. Reed Books, Sydney.

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  1. What Else?

    • Northern Banjo Frog / Northern Bullfrog (Limnodynastes terraereginae): has red colouration around its groin.
    • Giant Banjo Frog (Limnodynastes interioris): has a bright orange or yellow belly with no mottling.
    • Common Spadefoot Toad (Neobatrachus sudelli): doesn’t have the gland on the outer side of its hind legs. Giant Burrowing Frog (Heleioporus australiacus): doesn’t have the gland on the outer side of its hind legs.
    • Mallee Spadefoot Toad (Neobatrachus pictus): doesn’t have the gland on the outer side of its hind legs.
  1. Did You Know?

    The females have special flaps of skin on their fingers which are used to carry air bubbles from the surface of the water into the foam nest containing the eggs.

    There is so much variation in colour, size and call, that scientists have grouped this species into five subspecies.

  1. Listen to the Call

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