The Bibron's Toadlet or Brown Toadlet, (Pseudophryne bibronii) is a species of Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

n ground-dwelling frog, that although has declined over much of its range, is widespread through most of New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

, Victoria

Victoria (Australia)

Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....

, south-eastern Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

 and eastern South Australia

South Australia

South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

, including Kangaroo Island

Kangaroo Island

Kangaroo Island is Australia's third-largest island after Tasmania and Melville Island. It is southwest of Adelaide at the entrance of Gulf St Vincent. Its closest point to the mainland is off Cape Jervis, on the tip of the Fleurieu Peninsula in the state of South Australia. The island is long...

.

Physical description

This species is variable and may represent more than one species. It grows to about 30mm in length and is brown, grey or black above, often with scattered red spots. It is normally strongly marbled black and white on the ventral surface, however in some areas this marbling can be faint. There is always an orange, red or yellow patch in the armpits. This patch varies from yellow to orange between sites. At the Jervis Bay

Jervis Bay

Jervis Bay is a large bay bounded by the state of New South Wales, the Jervis Bay Territory, and a detached enclave of the Australian Capital Territory. HMAS Creswell is located between Jervis Bay Village and Greenpatch in the Jervis Bay Territory.-History:...

 region this patch is always yellow, this may be a result of hybridisation with the Southern Toadlet (Pseudophryne dendyi) which has a strong yellow patch in the armpits. There is also a yellow/orange patch or raised bump on the back of the thigh.

Behaviour and ecology

This species inhabits areas that are likely to be inundated after rain. This can be anything from coastal swamps, creeks, temporary ponds/roadside ditches in forest, cleared land, heathland and even sub-alpine areas. When threatened, the Bibron's Toadlet will often lie on its back, unresponsive, pretending to be dead. This performance had been reported to last for up to an hour.

Reproduction

The males attract the females by making a grating "ark" noise from a concealed area, in mud, under rocks or damp leaf litter. They normally call after heavy rain or when water is available, they call all year round but normally from February to June at temperatures as low as 4 °C (39.2 °F).

The species is polyandrous

Polyandry

Polyandry refers to a form of marriage in which a woman has two or more husbands at the same time. The form of polyandry in which a woman is married to two or more brothers is known as "fraternal polyandry", and it is believed by many anthropologists to be the most frequently encountered...

, with each female mating with several males. The female visits up to eight males, mates with each, and deposits eggs in the shallow nest he has dug. The female moves on and the male tends the nest. The nest, which may contain moist leaf litter or sphagnum moss

Sphagnum

Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...

, floods during rain. The eggs hatch and the tadpole

Tadpole

A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...

s develop in the water. If no sufficient rain happens soon after laying the eggs can remain unhatched for many weeks, with the tadpoles developing inside. The nest must stay wet so the eggs remain moist, but not too wet or they will be washed away. Female frogs that mate with more males, thus depositing eggs in more nest sites, are more likely to have some young survive.

Sources

• Anstis, M. 2002. Tadpoles of South-eastern Australia. Reed New Holland: Sydney.
• Robinson, M. 2002. A Field Guide to Frogs of Australia. Australian Museum/Reed New Holland: Sydney.
• Frogs Australia Network-frog call available here.
• SA EPA's Frogs of South Australia website