Growling Grass Frog - king of frogs
2008-08-24
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In the Australian amphibian world the Growling Grass Frog is what you might call a heavy hitter. One of our largest frogs, it can live for up to 18 years and has a reputation as a “frog eater”.
Growlers can hear other frog species’ calls and use this skill to zone in on them when hunting for food, adding them to a diet that includes insects, tadpoles, small lizards, fish and the occasional tiny bird.
Although most active at night, Growlers also love basking in the warmth of mild, sunny days.
Spotting a growler
Active during the warmer months of the year, Growlers are usually found in large swamps,
ponds and lakes, as well as man-made bodies of water such as farm dams, disused quarries and irrigation channels.
Measuring up to 10cm from head to tail, Growlers have a white, granular belly and their back colour ranges from brown or dull olive to bright emerald green with black or bronze spots and lines. They also carry large warts, a trait that distinguishes them from the similar-looking Green and Golden Bell Frogs.
Growlers have no problems seeing during daylight hours and if they hear you coming will jump into the water with a distinctive “plop”, often the only way to know they are around during the day.
Their call is not dissimilar to the sound of an outboard motor struggling into action – “crawark-crawark-crok-crok”.
Rocked by Chytrid Fungus
As recently as the early 1980s Growlers were considered common across much of south-eastern Australia and Tasmania.
But since then numbers have plummeted. Growlers can no longer be found in the ACT and are listed as threatened in NSW, Victoria, South Australia and Tasmania.
Suffering from loss of habitat, predation by introduced fish as well as livestock overgrazing around the edges of wetlands, Growler numbers have also been hit hard by a frog killing disease called Chytrid Fungus.
This devastating disease, which grows in a frog’s skin and creates a layer of matting that stops them from breathing, has already led to the loss of 70 frog species from Central and South America and could be behind the extinctions of eight Australian frog species.
The fungus is believed to have arrived in Australia in the 1930s with the introduction of the African Clawed Frog, which was then used in pregnancy tests.
Urine samples from pregnant women were injected into the frog and if a woman was pregnant her urine would cause the frog’s ovaries to start producing eggs.
What nobody realised was that the African Clawed Frog carried the deadly Chytrid Fungus.
Scientists have warned Chytrid Fungus has the potential to wipe out a quarter of the world’s frog species. It can travel at up to 100km a year in Australia and has infected frog populations across the country.
Although there is no cure yet for this terrible disease, we can all take measures to prevent its spread, including:
- Don’t remove frogs or tadpoles from a body of water.
- The spores are water borne so care should be taken not to transport water or mud whenever you are near wetlands, dams, ponds or other bodies of water.
- Avoid touching frogs but if you must do so use wet gloves (water) then sterilise with bleach before disposing of the gloves. Bleach would harm the frog.
- Help educate others about the disease.
- Help survey Growler populations for fungus infections by joining the Chytrid Fungus Mapping Project (Victoria). Contact Ray Draper to find out how by emailing raydraper2004@gmail.com.
Where you might hear a Growler
NSW: Mulwala State Forest, Bondi State Forest, Cocoparra National Park and the Willandra Lakes World Heritage Area.
Victoria: Grampians National Park, Wilson’s Promontory National Park, Nooramunga Marine and Coastal Park.
SA: Bool Lagoon Game Reserve, Messent Nature Reserve.
Tasmania: Mt William National Park, Freycinet National Park, St Helens Conservation Area, Waterhouse Conservation Area, Tamar River Wildlife Sanctuary, Tamar Conservation Area.
Legal status
The current conservation status of the Southern Bell Frog, Litoria raniformis, under Australian and State/Territory Government legislation is as follows:
National: Listed as Vulnerable under the Environment Protection and Biodiversity Conservation Act 1999.
NSW: Listed as Endangered under the Threatened Species Conservation Act 1999.
Tasmania: Listed as Vulnerable under the Threatened Species Protection Act 1992.
Victoria: Listed as Threatened under the Flora and Fauna Guarantee Act 1988.
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