Southern Bell Frog

Scientific name:  

Litoria raniformis

Other common names

Growling Grass Frog, Warty Swamp Frog, Green Swamp Frog, Green and Golden Frog

Description

The body of the Southern Bell Frog is mottled with colours ranging from brown and dull olive-green to bright emerald green on its back with large brown, golden, black or bronze spots.  A pale green stripe runs down its spine.  Its back is covered in shallow bumps, large warts, lumps and skin folds.  It has a dark streak running from its snout and over its eyes and its tympanum (the membrane covering the entrance to the ear).  Above this streak a cream coloured fold of skin runs down to its groin.  Another pale stripe runs from below its eyes to the base of its front legs.  Its groin and the backs of its thighs are bright blue to a turquoise colour, occasionally with yellow flecks.  The skin on its belly is coarsely granular and white to a pale cream colour.  The toes on its front legs are not webbed, but the toes on the back legs are almost fully webbed.

The males are much smaller than the females.  The males are only 5.5cm to 6.5cm long compared to the female's length of 6cm to 10.5cm.

The voice of the Southern Bell Frog is varied.  It has been described as, a loud barking call, a series of grunts - like a distant motorbike, short grunts "crok-crok" followed by a slow "craw-craw-crawk", a three part moaning "Craw-ork ar-ar", rising and falling in tone, and a "crawark-crawark-crok-crok" growl of about one second duration.

Habitat

The Southern Bell Frog is native to south-eastern Australia and has been found from southern South Australia along the Murray River though Victoria to New South Wales and the Australian Capital Territory.  It also has populations in the north and east of Tasmania and on Bass Strait Island.  It lives at altitudes from sea level (0m) to 1300m.

This frog is found in permanent bodies of water with abundant growth of vegetation near the bank.  The Southern Bell Frog is found throughout the swamps of the River Murray and the South East.  The Southern Bell Frog also lives in dams, ponds and marshes, either amongst sedges and other semi-aquatic vegetation, or sheltering under logs and rocks.

This species of frog is associated with permanent bodies of water.  It is not clear if it also lives in temporary bodies of water.

The Southern Bell Frog occurs in both woodlands and areas of improved pasture.

Behaviour

The Southern Bell Frog is a voracious predator.  They eat invertebrates such as beetles, termites, cockroaches and moths.  They also prey on other frog species and are also known to be cannibalistic.  They are ‘sit-and-wait' predators, that is, they sit and wait for their prey to come along.

This frog is an agile climber and is classified as a tree frog, but it is most often found amongst dense reeds or along swampy grasslands.  During the day this frog hunts and basks in the sun.

The Southern Bell Frog breeds in permanent ponds or swamps, usually with extensive areas of sedges and rushes from which adults call.  The female frog can reproduce at 2 to 3 years of age.  The males develop black rough nuptial pads on their thumbs during the breeding season.  Males call after rain in spring, summer and autumn while floating amongst vegetation.  Breeding mainly occurs in spring and summer.

The females lay at least 1000 eggs, although some females have been recoded laying more than 1600 eggs.  The eggs are laid in a in a loose clump on the surface in shallow water.  They are deposited in a floating raft, often attached to vegetation, which later sinks.  The eggs are large and likely to be opaque white with a copper sheen.

Southern Bell Frog tadpoles are large and initially are dark in colour.  As they develop the body wall becomes yellow, or copper, and an iridescent green pigment forms over the brain and spine.  They then become a pinkish-grey colour with yellow fins.  These tadpoles dart into deeper water when disturbed.  They can grow up to 10cm long and are free swimming.

Metamorphosis takes place between late summer and autumn.  They may remain as tadpoles over winter and metamorphose the following season.  These frogs stay in tadpole stage for at least one year.

Notes

The common name varies between states.  It is called the Southern Bell Frog in New South Wales, the Growling Grass Frog in Victoria and South Australia and the Green and Gold Frog in Tasmania.

Little is known about the biology of the Southern Bell Frog but it is likely to be similar to that of Green and Golden Bell Frog (Litoria aurea) which it closely resembles.  It can be distinguished by the shallow bumps on its back, a shorter call and a slightly different head and snout shape.  It can also be confused with the New England Swamp Frog, also known as the Yellow Spotted Tree Frog (Litoria castanea) but it can be distinguished by its lack of large yellow spots in the groin and on the backs of the thighs.

Status and Threats

Federal                               Vulnerable
South Australia                   Vulnerable
New South Wales               Endangered

Its population and distribution have been reduced to a critical level

Identified or suspected threatening processes include:

References/Sources

Anstis, M.  2002.  Tadpoles of South-eastern Australia.  Reed New Holland: Sydney.

Barker, J., G.C.  Grigg and M.J.  Tyler.  1995.  A Field Guide to Australian Frogs.  Surrey Beatty & Sons: Chipping Norton.

Cogger, H.G.  2000.  Reptiles and amphibians of Australia.  Reed Books: Sydney.

Robinson, M.  2002.  A Field Guide to Frogs of Australia.  Australian Museum/Reed New Holland: Sydney.

Website: Frog Australia Network

Website: Growling Grass Frog - Wikipedia, the free encyclopedia

Amphibian Research Centre: http://frogs.org.au/frogs/frog.php?frog_id=9

DEWR: http://www.environment.gov.au/sprat

Gillespie, G., Lemckert, F., Littlejohn, M., Robertson, P., Brereton, R.  & Brown, P.  2004.  Litoria raniformis.  In: IUCN 2006.  2006 IUCN Red List of Threatened Species.  <www.iucnredlist.org>.  Downloaded on 28 March 2007.