Wallum froglet

Common name: wallum froglet

Scientific name: Crinia tinnula

Family: Myobatrachidae

Conservation status: The wallum froglet is listed as Vulnerable in Queensland (Nature Conservation Act 1992). It is ranked as a high priority under the department's Back on Track species prioritisation framework.

Description

The wallum froglet is a small frog that grows up to 20 mm in length and has a pointed snout. The skin on the dorsal side (back or top side) may be smooth or have irregular rounded projections. Irregular dark markings, or stripes are evident on the dorsal side and colouration ranges from light grey, beige, red-brown to dark-brown. The ventral surface (front or bottom side) is granular, off-white with dark grey speckling or dark grey with white speckling and a distinct stripe runs down the throat and belly. The fingers and toes are unwebbed and toes do not have flattened disks or pads at their tips. Tadpoles are grey or brown above with irregular darker markings and have an oval shaped body and a tail that is 1.5 times the body length.

The wallum froglet is similar to other co-existing Crinia species (C. parinsignifera, C.signifera and and C. deserticola), although it can be distinguished by the faint row of white dots down the centre of the throat, and a more pointed snout that projects beyond the lower jaw.

Habitat and distribution

The wallum froglet is restricted to freshwater swamps in lowland coastal areas and is found in associated vegetation communities such as heath, sedgeland and woodland on nutrient-poor sandy soils. Acidic swamps and lakes in these areas provide essential breeding habitat for wallum-dependent frog species. The wallum froglet has also been observed in disturbed heath habitat.

The wallum froglet only occurs in lowland coastal habitats in south-east Queensland and north-east New South Wales and on the sand islands off the Queensland coast (Fraser, Bribie, Moreton and North Stradbroke Islands). The species range once extended from just north of Bundaberg in Queensland to Sydney in New South Wales. Although large populations have persisted in some of Queensland's protected areas, its distribution has been significantly reduced and fragmented.

Life history and behaviour

The wallum froglet can be active at any time of the day following rainfall events and is a terrestrial (lives on the land) species that breeds in acidic ephemeral (short lived) swamps. They can be heard calling at any time of the day following rainfall or when they are breeding, but may be found away from water under leaf litter. Males call from the base of sedges near water or atop matted sedge clumps. Calls are usually a short, high-pitched 'tcheh'.

Breeding usually occurs in autumn or early winter, but has been recorded in all seasons following rain. Spawning (egg laying) takes place in acidic waters where eggs are laid singly or in clumps attached to submerged vegetation. Tadpoles may take two-six months to develop into frogs.

Adults feed on small arthropods while tadpoles feed on sediment, detritus and algae.

Threatening processes

The wallum froglet has experienced significant population declines and range reductions due to habitat loss, fragmentation and modification from agricultural and urban development, establishment of exotic pine plantations and sand mining. Other potential threats to this and other wallum-dependent frogs include: predation of eggs and larvae by introduced fish; habitat degradation (from weed invasion, dry season wildfires, feral pigs, drainage of habitat, deterioration of water quality, use of biocides in weed and mosquito control); and disease spread through inappropriate handling.

Recovery actions

The National recovery plan for the wallum sedgefrog and other wallum-dependent frog species makes the following management recommendations for the conservation of wallum froglets:

  • Protect wallum froglet populations and manage remaining habitat to address threats.
  • Rehabilitate degraded wallum froglet habitat.
  • Learn more about the impacts of known and potential threats to inform management.
  • Conduct surveys to clarify the distribution of wallum froglet species, determine abundance and assess habitat condition.
  • Protect wallum froglet habitat on freehold land through voluntary conservation agreements such as Nature Refuges.

What can you do to help this species?

  • To protect habitat for wallum froglets, maintain vegetative buffers around known breeding sites, hydrological regimes and water quality to enable movement of animals between populations and catchments.
  • Ensure that activities on sites surrounding the wallum froglet habitat do not alter water tables, hydrological patterns and water quality.
  • Never release exotic fish into natural waterways, wetlands or dams (e.g. through disposal of aquarium collections, using exotic species as bait, or flushing fish down the toilet).
  • Handling of frogs should be avoided to prevent introducing disease.

Related information

Barker J, Grigg GC and Tyler MJ. 1995. A Field Guide to Australian Frogs. Surrey Beatty and Sons, Chipping Norton, NSW

Ehmann H, 1997, Wallum Froglet Crinia tinnula pp.48-55 in Ehmann H (ed). Threatened Frogs of New South Wales: Habitats, Status and Conservation, Frog and Tadpole Study Group of New South Wales Inc. Sydney, NSW,

Hines HB, Mahony MJ, and McDonald KR, 1999, An assessment of frog declines in wet subtropical Australia. In Campbell, A [ed.] Declines and Disappearances of Australian Frogs, Environment Australia, Canberra.

Meyer E, Hero JM, Shoo L and Lewis B, 2006, National recovery plan for the wallum sedgefrog and other wallum-dependent frog species. Report to Department of the Environment and Water Resources, Canberra. Queensland Parks and Wildlife Service, Brisbane.