Western Banjo Frog

Limnodynastes dorsalis

A large ground-dwelling frog, up to 7.5 cm. The back is grey or dark green with numerous, irregular dark brown blotches and a thin pale yellow line running along the centre of the back from nose to tail (where the specific name dorsalis comes from). Bright orange to red patches are present in the groin. Other distinguishing features are a glandular ridge at the corner of the mouth and large poison glands on the upper side of the calves. Male Banjo Frogs have thicker, more powerful arms than females and develop a dark throat as well as nuptial pads during the breeding season.

Breeding

Calling begins as early as May in the northern part of the range, and from July-August around Perth. Breeding continues through to early December.

Call

A single, explosive "bonk" repeated at intervals and answered by other male Banjo Frogs. Males call from dense overhanging vegetation such as grass and sedges around the water's edge. Calls can be heard from a considerable distance.

Eggs

During mating, the female beats the surface of the water to produce a white foamy mass. The eggs are laid into the base of this "foam raft" which is usually hidden beneath overhanging vegetation. The foam nest is unique among southwestern frogs.

Tadpoles

A relatively large tadpole up to 8 cm in length. The back is dark brown, almost black, sometimes with scattered black spots, while the underneath is dark with a blue hue. Tail fins are high, and lack pigment. Tadpoles are usually found in deep, permanent water, and may be present all year round, as development can be slow. Tadpoles metamorphose into froglets from early summer to April.

Other Notes

Adult and juvenile Banjo Frogs are often encountered a considerable distance from water. They are adept burrowing frogs and spend much of the year buried in sandy soils away from breeding sites.