Pseudophryne australis

Conservation Status

Vulnerable species in New South Wales (Threatened Species Conservation Act). At a national level it is regarded as an 'insufficiently known species that may be of concern'.

What does it look like?

This small frog has unusually colorful markings.  Its head is capped with a bright reddish orange triangular pattern, extending from between its eyes down to its snout. This colour is repeated in reddish orange spots across its back, and often appears as a short stripe on its tail.  This contrasts dramatically with the dark reddish-brown tint of its body. The skin on its back is smooth, with small warts. Its belly, however, has a striking pattern of black and white flecks. 

Despite its common name, the Red-crowned Toadlet is actually a frog.  However it does share one physical feature of many toads: it has relatively short fore- and hind legs.  Rather than hopping, it moves at a measured pace along the ground, alternating its legs in a walk or a crawl.  It does not have webbing on its fingers and toes.

The Red-crowned Toadlet can grow up to 20-25mm, and females are frequently larger than males.

Where does it live?

The Red-crowned Toadlet is found specifically in areas that have sandstone geology, including open woodland, eucalypt forest and heath.  They prefer steep escarpments and plateaus, and low undulating ranges.  Here they stay close to the ridge-top, where they hide under flat sandstone bush-rock.  But you may also find them nearby under logs, beneath thick ground litter, especially if it is near a large tree or in a rock crevice.  When breeding, they prefer to stay near the creeks that exist sporadically within the high ridge tops, feeding water to the streams below. Here they live in the generous amounts of moist, dense vegetation or litter on the ground.

Populations of the Red-crowned Toadlet are in decline.  It has disappeared from areas of northern and southern Sydney in which it was once common.  Now, it can be found only in isolated areas in Sydney on sandstone geology.

In Pittwater, the Red-crowned Toadlet has been recorded several times in the 1990s.  Sightings were recorded in:

• Deep Creek Reserve
• Narrabeen
• Ingleside
• Bayview

A specimen of the Red-crowned Toadlet was collected at Church Point in 1955 and is now held in the Australian Museum.

What does it eat?

The diet of the Red-crowned Toadlet is believed to be mainly ants and termites.  However, they supplement their diet with:

• Mites
• Pseudo-scorpions
• Small cockroaches
• Other minute, wingless primitive insects  (collembolans)

In the water, tadpoles feed on plant material and other debris.

What is its life cycle?

The Red-crowned Toadlet is gregarious!  You can find up to 30 frogs living in one colony, the males calling out with a distinctively nasal 'ank-ank' sound.  Perhaps because they live in habitat with unpredictable temperature and rainfall patterns, these frogs are opportunistic breeders.  Eggs have been found in all months of the year, and female frogs will take advantage of good conditions by laying multiple clutches of eggs.

Rather than spawn in water, the red-crowned toadlet mates and spawns on land. The male finds a mass moist, decomposing leaf litter and builds his nest.  He mates with several females who then lay their eggs in the nest, leaving the male to tend them.  He may attend up to 100 eggs at a time.  The eggs draw on the moisture in their surroundings, but they don't develop fully until there is sufficient rainfall. When the rain finally comes and the eggs are immersed, it is time for the tadpoles to hatch!  They are flushed by rain into a small pool or puddle - and it's essential for the rain to continue until they reach adulthood, between 28 - 180 day later.

Sadly, the reproductive success of the Red-crowned Toadlet is known to be quite low.  A local population at Hornsby Heights saw 1,368 eggs laid over three years.  Only 11 of these tadpoles became adult frogs. In the wild, many clutches of eggs can be lost when shallow pools or puddles dry up.

But if a tadpole survives to become an adult frog, the outlook is good. Compared to some frogs, the Red-crowned Toadlet can be one of the longest living frogs - up to 10 years in some cases.  

What are the threats?

Urban development in the Sydney basin has been intense in recent years and this has had its impact on the Red-crowned Toadlet. It has already become extinct at four local sites in Sydney, and many other breeding sites are threatened.  The key threats include:

• Habitat removal and fragmentation due to building development
• Storm water pollution
• Changes in water courses
• Changes in soil PH
• Alteration of plant species

The Red-crowned Toadlet is also susceptible to infection by amphibian chytrid fungus. This is a water-borne disease that affects many frog species, especially those in cooler climates. It may be an increased risk for the Red-crowned Toadlet due to its large colony size. 

What we can do to protect it?

There are many things we can do to protect the remaining populations of the Red-crowned Toadlet.  These include:

• Conservation of remnant bushland
• Creating and protecting wildlife corridors
• Protecting our waterways from degradation (pollution, siltation, erosion, weed invasion, hydrological changes), especially minor creeks draining sandstone plateaus, ridges and upper slopes
• Control dogs and cats
• Control foxes
• Control of predation on eggs and tadpoles by the introduced Plague Minnow (Gambusia holbrooki)
• Prevent the removal of bush-rock
• Rehabilitate sick or injured frogs
• Educate the community about this remarkable small amphibian

Updated: 21 Jun 2011