Distribution and Habitat

Country distribution from AmphibiaWeb's database: Australia

View distribution map in BerkeleyMapper.

Known from far northern Australia, specifically along the north-eastern Northern Territory and into north-western Queensland and the Mitchell Plateau in the remote western coast of the Kimberley Division of Western Australia. (These encompass the range of former species Uperoleia inundata (see Comments). In the Northern Territory and Queensland, the frog is confined to grassland and open forest at the edge of floodplains where monsoon rains temporarily flood the ground. Also, known to Inhabit areas that are partially flooded and cleared areas surrounded by sparse Livistonia and Eucalyptus forest.

Life History, Abundance, Activity, and Special Behaviors
Shelters in burrows. Breeding occurs in January and February. Males call from shallow water at the base of grass tussocks close to the water in flooded areas, under leaves and logs and from grass stems in water.

Clumps of about five or so eggs are laid in very shallow water and sink to the bottom. A female has been observed laying 368 eggs. Larval development has been reported to take 7-8 weeks, but may be shorter under drying conditions.

Comments
Using population genomic data (single nucleotide polymorphisms or SNPs), mitochondrial sequence data, behavioural call analysis, and morphological data, Jaya et al. (2022) examined a species complex of toadlets from northern Australia (Uperoleia borealis, U. crassa, U. inundata). The three species of frogs were morphologically indistinguishable and two had little to no genomic differences, leading the authors to synonymize U. inundata with U. crassa.

References

Barker, J., Grigg, G. C., and Tyler, M. J. (1995). A Field Guide to Australian Frogs. Surrey Beatty and Sons, New South Wales.

Cogger, H.G. (1992). Reptiles and Amphibians of Australia. Reed Books, New South Wales.

Davies, M., McDonald, K.R., and Corben, C. (1986). ''The genus Uperoleia Gray (Anura: Leptodactylidae) in Queensland, Australia.'' Proceedings of the Royal Society of Victoria, 98(4), 147-188.

Jaya FR, Tanner JC, Whitehead MR, Doughty P, Keogh JS, Moritz CC, Catullo RA (2022). "Population genomics and sexual signals support reproductive character displacement in Uperoleia (Anura: Myobatrachidae) in a contact zone." Mol Ecol., 17, 4527-4543. [link]

Tyler, M.J., Crook, G.A., and Davies, M. (1983). ''Reproductive biology of the frogs of the Magela Creek System, Northern Territory.'' Records of the South Australian Museum, 18, 415-440.

Tyler, M.J., Smith, L.A., and Johnstone, R.E. (1994). Frogs of Western Australia. Western Australian Museum, Perth.

Species Account Citation: AmphibiaWeb 2023 Uperoleia crassa: Fat Toadlet <https://amphibiaweb.org/species/3608> University of California, Berkeley, CA, USA. Accessed Jan 28, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 28 Jan 2025.

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