Southern bell frog

Southern bell frog – olive version. Photo: Sascha Healy, OEH

Southern bell frog – olive version.
Photo: Sascha Healy, OEH

The southern bell frog (Litoria raniformis) is one of the largest frogs in Australia. It reaches up to 104 mm in length, with females usually growing larger than males. These amphibians vary greatly in colour and pattern but are typically olive to bright emerald green, with irregular gold, brown, black or bronze spotting with a pale green stripe down the centre of their back.

Where is the southern bell frog found?

Once abundant along the Murray and Murrumbidgee rivers and their tributaries, from the Southern Tablelands to the South Australian border, the southern bell frog is now only found in scattered locations throughout its former NSW range. Currently, the species is known to exist only in isolated populations in the Coleambally Irrigation Area, the Lowbidgee floodplain and around Lake Victoria. It is also found in Victoria, Tasmania and South Australia.

In NSW, the southern bell frog is usually found in or around permanent or impermanent swamps dominated by black box-lignum-nitre goosefoot, lignum-typha and river red gums or in billabongs along floodplains. They are also found in irrigated rice crops, particularly where there is no available natural habitat.

What does this frog need to thrive?

Southern bell frog - green version. Photo: Sascha Healy, OEH

Southern bell frog - green version. Photo: Sascha Healy, OEH

The southern bell frog is highly sensitive to changes to water flows, flooding regimes and soil moisture. It prefers seasonally flooded waterbodies which retain pooled water for at least five months, and does not generally tolerate extended drying. It is active only in spring and summer and therefore does not benefit from winter flooding unless the water remains pooled through spring and summer. It can breed successfully in permanent water bodies as long as carp are absent or in low numbers.

The southern bell frog breeds during the warmer (September to April) months, with breeding triggered by flooding or a significant rise in water levels. Tadpoles require standing water for at least four months for development and metamorphosis to occur but can take up to 12 months to develop in cooler regions. Metamorphs emerge from waterbodies in summer and autumn months when they are around 25-34 mm in length. After metamorphosis young southern bell frogs can remain around the same waterbody for several weeks until they gain sufficient body condition to be able to move to new habitats.

The southern bell frog eats a variety of prey including tadpoles, other frogs (including members of the same and other species), small fish, water snails, and a range of insects including flies, beetles, beetle larvae and grasshoppers.

Status and threats to the southern bell frog in NSW

Water purchases by NSW and Commonwealth governments in recent years have increased environmental water allocations available to the Murrumbidgee Catchment, and these allocations have been used successfully to maintain key southern bell frog populations. In 2009 and 2010 environmental watering saw recolonisation of southern bell frogs in the Lowbidgee and mid-Murrumbidgee wetlands, after they had been absent from some sites for several years.

The principal threats to the southern bell frog’s survival include:

  • alteration to natural flooding regimes
  • draining of waterbodies
  • removal of native vegetation, fallen timber, leaf litter and other ground cover
  • infection by the chytrid fungus
  • anthropogenic climate change
  • predation by exotic fish such as carp, goldfish and gambusia
  • pollution of water bodies by chemicals and runoff.

Altered flooding regimes from water extraction and river regulation may either divert water away from previously flooded wetlands or cause some areas to become permanently flooded. Increases in wetland permanency tend to cause declines in the diversity of aquatic vegetation and increases in alien fish populations which makes these wetlands unsuitable breeding habitat for this species. Other effects of altered flooding regimes are flooding at the wrong time of the year, infrequent flooding, and drying out of waterbodies before tadpoles are able to develop sufficiently.

The southern bell frog has suffered a considerable reduction in abundance and distribution throughout NSW in recent years. As a result it is listed as endangered in NSW under the Threatened Species Conservation Act 1995.

Many of the known remaining populations of the southern bell frog occur on private land and in river red gum reserves. A draft recovery plan for the southern bell frog has been prepared to guide its conservation. One of the aims of the recovery plan is to work cooperatively with landholders to protect the southern bell frog from threats and ensure its survival.

Activities identified in the recovery plan to help the survival of the southern bell frog include:

  • removing exotic fish species from waterbodies and preventing their introduction into new waterbodies
  • eradicating pest species, for example, pigs that may be degrading potential southern bell frog habitat
  • avoiding fires around waterbodies and through impermanent wetlands when dry
  • maintaining ground cover such as fallen timber and leaf litter, rocks and vegetation, particularly within a 1 km radius of permanent waterbodies and throughout impermanent wetlands
  • ensuring that the regular flooding of southern bell frog habitats occurs each year during spring and early summer, and that water remains pooled on the ground for at least five months for tadpoles to develop
  • preventing chemicals, for example, pesticides and herbicides from entering waterbodies or being sprayed near known southern bell frog habitats.


Page last updated: 31 March 2014