Eastern Banjo Frog, Limnodynastes dumerilii

Detailed introduction

The Eastern Banjo Frog ( Limnodynastes dumerilii ) is a medium-sized, native Australian frog with a distinctive call. Because the male's "bonk… bonk…" call sounds very much like the plucking of a banjo string, it is also known as the "Pobblebonk" in English.

Classification and nomenclature

• Commonly used Chinese name: Eastern Banjo Frog (also translated as Eastern Bob Frog, etc., there is no unified Chinese name yet)

• English name: Eastern Banjo Frog, Pobblebonk

• Scientific name: Limnodynastes dumerilii

• Family and Genus: Limnodynastidae ( Limnodynastes )

Appearance and Identification Features

The Eastern Banjo frog is sturdy and adept at digging, making it a typical terrestrial "burrowing frog."

• Size: Adults are generally about 6–8 cm long, with females usually being slightly larger than males;

• Body shape: Sturdy body, broad but not protruding head, strong limbs, especially the hind limbs which are good for digging soil;

• Back color: The back is mostly brown, grayish brown, olive or dark brown, often with irregular dark patches or cloud patterns;

• Sides of the body and thighs: Yellow or orange patches are often visible on the sides of the body and the back of the thighs, which are one of the important clues for identification in the field;

• Abdomen: The abdomen is white or cream-colored, and may have fine gray or brown spots;

• Skin texture: The back is slightly rough but not as wart-like as a toad, and the overall texture is between smooth and rough.

Compared to some brightly colored tree frogs, the Eastern Banjo frog has a more understated camouflage coloration, making it better suited to hiding among mud, fallen leaves, and riverside vegetation.

Distribution range and habitat

The Eastern Banjo Frog is a common frog species in southeastern Australia .

• Its distribution area includes New South Wales, Victoria, Tasmania, and parts of South Australia;

• Its traces can be found from coastal plains to foothills and hills.

It is highly adaptable to different habitats, but generally prefers humid environments.

• Natural environment: marshes, streams, floodplains, lake and pond shores;

• Artificial environments: farmland ponds, pasture dams, urban park ponds, roadside ditches, and garden water features;

• Any body of water with persistent or seasonal flooding, along with surrounding mud or sandy loam that can be dug out, can become its habitat.

Habits and calls

The Eastern Banjo frog is a burrowing, nocturnal frog .

• During the day, they hide in self-dug holes, under rocks, or in thick layers of fallen leaves to avoid moisture evaporation;

• They are most active at dusk and night, especially before and after rainfall;

• Male frogs call out at the edge of the water or in shallow water, making a distinctive "bonk… bonk…" or "pobble-bonk" sound, as if someone is gently plucking the strings of a banjo, hence the name.

During the breeding season, dense banjo choruses can often be heard around ponds and farmland dams, but because they are mostly hidden near waterside vegetation and soil, they are not always easy to spot visually.

feeding habits

The Eastern Banjo Frog is a typical small carnivorous predator, primarily feeding on invertebrates:

• Insects such as beetles, crickets, cockroaches, and moths on the ground and in low vegetation;

• Small arthropods and mollusks such as ants, spiders, and slugs;

• Occasionally, they will also eat small frogs or tadpoles of suitable size.

They often move slowly at night or lie in ambush near the water, using their keen eyesight to catch moving prey, and then quickly extend their sticky tongues to capture them.

Reproduction and Development

The reproduction of the eastern banjo frog is closely related to rainfall and water bodies:

• The breeding season mostly occurs in warm, humid months, and after rainfall, male frogs will gather around the water to call out.

• Female frogs lay their eggs in still or slow-moving water.

• The eggs are encased in unique foam nests (foam egg clusters) and float on the water surface or attach to waterside vegetation;

• Tadpoles develop in water, are relatively large in size, and have a certain tolerance to temperature and dissolved oxygen.

• After transforming into tadpoles, they will go ashore to find suitable soil areas and enter the terrestrial life stage.

Protecting the status quo and threats

The Eastern Banjo Frog is currently assessed as Least Concern (LC) on the International Union for Conservation of Nature (IUCN) Red List, indicating that it has a wide distribution, a large population, and remains relatively stable in most areas.

Local populations may be affected by the following factors:

• Wetland landfilling, water pollution, and pesticide use;

• Habitat fragmentation caused by urban sprawl and land development;

• Climate change is causing changes in rainfall patterns and the risk of prolonged drought.

Maintaining diverse and clean ponds, farmland dams, and wetlands, as well as preserving natural vegetation along waterfronts and excavable soil environments, contributes to the long-term survival of the eastern banjo frog and other waterfront frogs.