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Red-crowned toadlet

Red-crowned toadlet

What is a red-crowned toadlet?

The red-crowned toadlet is a small frog species found in sandstone forests across the Sydney region. The scientific name for this species is Pseudophryne australis.

Red-crowned toadlets measure up to three centimetres long and are dark brown or black in colour with a distinctive red T-shaped patch on their head and another red patch along their rump. Its belly is marbled black and white. 


What do red-crowned toadlets sound like?

Red-crowned toadlets can be distinguished from other amphibians based on their call which sounds like an ‘ark’ or ‘squelch’ sound. Red-crowned toadlets can be heard all year round. 


Where does the red-crowned toadlet live?

Red-crowned toadlets live in damp areas of sandstone open forests in colonies of 20 to 30 individuals. Red-crowned toadlets take shelter in crevices and under rocks and logs. They forage in thick piles of leaf litter.

During the breeding season red-crowned toadlets gather in areas of dense vegetation near creeks and gutters. 

During long dry periods red-crowned toadlets use their strong hind feet to dig beneath the soil where there is more moisture.

Red-crowned toadlets are an example of a ‘cryptic’ species, meaning they are difficult to find. They rarely come out in the open, even at night. The toadlets move between cracks in the sandstone or beneath the leaf litter.


What does the red-crowned toadlet eat?

Red-crowned toadlets are carnivores. They eat small leaf litter invertebrates such as thrips, springtails, small ants and termites. The average red-crowned toadlet may eat six termites in one day.


What eats the red-crowned toadlet?

Red-crowned toadlets are known to be prey items for snakes and bandicoots. 

Many birds and reptiles are unable to eat red-crowned toadlets because they are toxic to them. The red colouring of the toadlet is a structural adaptation that acts as a warning signal to potential predators.


How do red-crowned toadlets reproduce?

Red-crowned toadlets breed in spring and summer, usually after rain. 

Unlike many amphibians, red-crowned toadlets lay their eggs on land. The female lays approximately 20 eggs in a nest made under damp leaf litter or in small log holes close to a water source.

Some male toadlets have been seen guarding their nest.


What is the life cycle of red-crowned toadlets?

 
Like most amphibians, the red-crowned toadlet life cycle consists of an egg, tadpole and adult stage. This transformation is known as metamorphosis. However, as the red-crowned toadlet is a terrestrial amphibian species, it has special adaptations that allow it to survive, grow and develop without the need for water.


Red-crowned toadlets begin their life as jelly-like eggs.


Baby frogs are called tadpoles. This is the larval stage of the amphibian life cycle. As red-crowned toadlets do not live in water, most of the development of red-crowned toadlet tadpoles takes place inside the egg where there is enough moisture.

When it rains, the partially developed tadpoles are released from their nests into a nearby pool of water. The tadpoles do not look like adults. They are black, have a tail, and are sometimes longer than the adults.

 


Over the course of up to three months, the tadpoles metamorphose into adults. The tadpoles grow legs and lose their tail. 

Adult red-crowned toadlets are relatively long-lived amphibians. Males live seven to eight years, whilst females can live up to 15 years.


What threats do red-crowned toadlets face?

 
Red-crowned toadlets are considered a vulnerable species. This is because their population ranges have been decreasing due to urbanisation. Human activities that threatened red-crowned toadlets include:
  • habitat clearing for housing development
  • collection of bush rock
  • recreational activities that disturb their breeding habitat, for example, bikes and four-wheel drive vehicles
  • climate change.

Red-crowned toadlets are also affected by the deadly chytrid fungus.

To protect this species it is important for us to protect their habitat from being cleared or damaged, reduce pollutants from enterring local waterways and minimise the effects of climate change.

References

FrogID, n.d. Pseudophryne australis. [online] FrogID. Available at: <https://www.frogid.net.au/frogs/pseudophryne-australis>.

FrogID Team, 2021. Red-crowned toadlet. [online] Australian Museum. Available at: <https://australian.museum/learn/animals/frogs/red-crowned-toadlet/>.

NSW Office of Environment & Heritage. 2017. Red-crowned toadlet - profile. [online] Available at: <https://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=10692>. 

Image attributions

Termites are a main source of food for red-crowned toadlets - "Termites" by Gnilenkov AlekseyCC BY 2.0 

The bright red patches of the red-crowned toadlet ward off predators. - "Pseudophryne australis frog_5885" by eyeweedCC BY-NC-ND 2.0

A clutch of red-crowned toadlet eggs - "Pseudophryne australis eggs" by Doug Beckers. CC BY-SA 2.0

Red-crowned toadlet eggs - "Pseudophryne australis eggs" by Doug BeckersCC BY-SA 2.0

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