32.
Giant Barred Frog
(Mixophyes iteratus)
EN
Overview
At a length of up to 120 mm, this is Australia's largest species of frog. The giant barred frog is night-active and breeds in streams, although the eggs are deposited out of the water under overhanging banks. Clutch sizes are very large, with between 1,343 to 4,184 eggs being counted in the wild. It occurs in both uplands and lowlands in rainforest, as well as farmland, and is found in many protected areas, but is still declining across its range. Threats to this species may include the destruction and degradation of its stream habitat through the impact of invasive species such as weeds and feral animals, timber harvesting and urban development.
Urgent Conservation Actions
A Recovery Pan was developed for this species in 1997 and all of the actions features here should be continued.
Distribution
Southeast Queensland south to mid-eastern New South Wales, Australia.
Fact
At a total length of up to 120 mm, the giant barred frog is Australia’s largest frog. However, this species is dwarfed by the world’s largest frog, which is a West African species called the Goliath frog that can reach body lengths of 400 mm and weigh 3.1 kg.
Evolutionary Distinctiveness
Order: Anura
Family: Myobatrachidae
The Myobatrachidae family (commonly referred to as the “Australian toadlets”) arose during the early Cretaceous period around 100 million years ago, a time when dinosaurs were still abundant on Earth. The family is distributed throughout Australia and southern New Guinea, and includes 80 species which comprise Australia’s dominant ground-dwelling frogs. The Myobatrachidae is notable among amphibian groups because most of the species exhibit some form of parental care, including the carrying of tadpoles in pouches, similar to marsupial mammals.

There are only eight species in the Mixophyes genus, which are commonly referred to as the “barred frogs” because of the distinctive dark barring patterns across their legs. They diverged from all other amphibian about 90 million years ago in the Late Cretaceous, which make them as distinct from their closest relatives as elephants are from aardvarks.
Description
This is Australia's second largest species of frog, reaching a maximum size of about 120 mm in length. The upper half of the eye is golden in colour, with the bottom half being darker, and the snout of the frog is broadly pointed. The toes are fully webbed, but the fingers have no webbing. The giant barred frog is typically dark brown on the dorsal or upper surface, the skin of which is fairly smooth, with some spots of variable size in a darker colour. However, this specie smay be a wide range of colours from dark olive green to black. A thin dark stripe runs from the snout, through the eye, and down past the eardrum. There is a dark triangle shape on the end of the snout starting from the nostril, with a paler triangle present behind it that stretches the eye. The legs have a distinctive laterally barred pattern. The thighs and side are pale yellowish in colour with many darker spots. The underbelly is white and smooth.

The tadpoles are large, growing to over 100 mm in length. They are deep-bodied and ovoid, with a thick, muscular tail that is twice the length of the body. The fins are low and opaque with dark flecking, except for the upper half of ventral fin, which runs below the tail and body. The tadpoles are coloured yellow-brown above with dark spots and a dark patch at the base of tail, with the underside being silver-white. The heart and lungs are visible from below through translucent skin (except when the tadpole is near metamorphosis).
Ecology
The giant barred frog is night-active and breeds in streams, although the eggs are deposited out of the water, under overhanging banks or on steep banks of large pools. Clutch sizes are very large in this species, with egg counts of between 1,343-4,184 being observed in the wild. Egg size is very small, diameter ranging from 1.6-1.8 mm. Relatively little is known about the reproductive biology of this species. Males call from concealed positions during the summer (September to April). The call of the male giant barred frog is a deep guttural grunt. During mating, the males clasp the females from behind around the chest, just under the arms, in a behaviour termed “axillary amplexus”, but egg deposition has not been documented. Tadpoles of this species have been found throughout the year and over-winter. Laboratory reared metamorphs (i.e. newly developed froglets) reach 28-30 mm in total length.

Spatial movements of four male and four female giant barred frogs were monitored at Coomera River, south-east Queensland in 1999. Over a period of six weeks, the average area used by females and males was 622 m2 and 403 m2 respectively. Individuals moved a maximum distance of 268 m along the stream and 50 m away from the stream. Giant barred frogs seem to be fairly territorial, with the distance between their day-time refuges and night-time areas being small, which suggests a high degree of fidelity to the previous day's shelter. Adults are often found half-buried under leaf litter.
Habitat
The giant barred frog occurs in both uplands and lowlands in rainforest and wet sclerophyll forest, including farmland. Populations have been found in disturbed areas with strips of stream-side vegetation on cattle farms and in regenerated logged areas. Many sites where the giant barred frog is known to occur are found along the lower reaches of streams which have been affected by major disturbances such as clearing, timber harvesting and urban development in their headwaters. They have also been found in eucalypt plantations and in streams running through partially cleared lands
Distribution
This species is distributed from Belli Creek near Eumundi, southeast Queensland, south to Warrimoo mid-eastern New South Wales in Australia. The extent of occurrence of the giant barred frog is approximately 106,000 km sq.. It is currently known from mid to low altitudes below 610 metres above sea level. In southeast Queensland, this species is currently known from scattered locations in the Mary River catchments downstream to about Kenilworth, Upper Stanley River, Caboolture River and Coomera River.
Population Estimate
No population estimate currently exists for this species, although numerous studies and surveys indicate that the wild population has declined and the range of the species has contracted. During the early 1980's, the giant barred frog declined and disappeared from at least two streams in the Conondale Range. The Bunya Mountains and Cunningham's Gap previously supported this species, but recent targeted surveys and intensive monitoring of these sites, and surrounding areas, have been unsuccessful in locating any giant barred frogs. Assessing the extent of the decline is difficult because of the lack of baseline data on its distribution and abundance, but this species is known to have suffered major declines in the southern portion of its range in the Sydney Basin Region, where in 2000 populations were only recorded at 2 of the 14 historical sites surveyed. There are no recent records from the Blue Mountains and the giant barred frog is currently only known from five populations in the Watagan Mountains area. A population was recently located in the southern Nambucca River catchments, and northward of this there is currently a large population in the Dorrigo-Coffs Harbour area, North Washpool and Bungawalbin State Forest. In far northeast New South Wales, this species is known from only three broad areas (Mebbin, Whian Whian and Richmond Range), despite intensive surveys across this region. The density of these populations was relatively low, with an average abundance of 4.2 individuals per 100 metres of stream transect between 1997 and 1998, and an average of 3.4 individuals over the same transects in 1999.
Population Trend
This species is registered as in decline by the IUCN Red List of Threatened Species.
Status
The giant barred frog is listed as Endangered in the IUCN Red List of Threatened Species because its area of occupancy is less than 500 km sq., its distribution is severely fragmented, and there is continuing decline in its area of occupancy, in the extent and quality of its habitat, in the number of subpopulations, and in the number of mature individuals. It is also listed as Endangered in the Nature Conservation Act (Wildlife) of the Australian Government.
Threats
Many sites where the giant barred frog occurs are along the lower reaches of streams, which have had major disturbances such as clearing, timber harvesting and urban development in their headwaters. In the Dorrigo area, this specie has been found to be less abundant in recently logged areas and sites where there was little undisturbed forest. The degree to which factor such as feral animals, domestic stock, weed invasion and the disturbance to stream-side vegetation threaten current populations is unknown. Surviving populations of the giant barred frog now generally exist in small, isolated patches of forest. The effect this may have on genetic variation within declining populations, and the general health of individuals, is also unknown. This species does colonise plantations and vegetated streams in otherwise cleared agricultural lands, which is a positive sign for the survival of the species, but also indicates that such sites can be of some significance and any clearing of this vegetation may negatively impact this species.
Conservation Underway
This species is listed as endangered in Australian legislation. Much of its habitat is protected within National Parks and State Forests, such as Conondale, Lamington and Main Range National Parks, and Ingelbar, Kenilworth, Spicer's Gap and Blackall State Forests in Queensland, and Gibraltar Range, Guy Fawkes River, Nightcap, Bril Bril, Ingelba, Maria River, McPherson, Mount Boss, Watagan, Wyong, Mebbin, Mount Warning and the Richmond Range National Parks, and Wild Cattle Creek, Kangaroo River, Orara West, Orara East, Clouds Creek, Doubleduke, Ewingar, Whian Whian, Upper Allyn River, Middle Brother, Bungawalbin, Washpool and Olney State Forests in New South Wales. Research and monitoring is in place for this species.
Projects
Conservation Proposed
A Draft Recovery Plan for the giant barred frog was compile in 1997, and several recommendations were made for the conservation of this species, including conducting regular, long-term population monitoring; further develop of husbandry and translocation techniques to improve future captive breeding initiatives; investigating the genetic structure of populations and the role of disease in this species’ decline; developing protocols for frog handling; improving prescriptions for effective habitat protection and management; and distributing a range of materials to increase public education and information about the plight and conservation of the giant barred frog.
Associated EDGE Community members

Frank specialises in the conservation biology of frogs

SAVE THE FROGS! Founder, Executive Director & Chief Ecologist Dr. Kriger holds a Ph.D. in Environmental Science from Griffith University in Gold Coast, Australia. His current research focuses on the amphibian disease chytridiomycosis.

Links
References
AmphibiaWeb: Information on amphibian biology and conservation [web application]. 2006. Berkeley, California: AmphibiaWeb. Available: amphibiaweb. Accessed: 08 December 2006.

Anstis, M. 2000. Tadpoles of south-eastern Australia: A guide with keys. Reed New Holland Publishers, Sydney.

Baillie, J. and Groombridge, B. (compilers and editors) 1996. 1996 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland.

Frost, D. R., T. Grant, J. Faivovich, R. H. Bain, A. Haas, C. F. B. Haddad, R. O. De Sá, A. Channing, M. Wilkinson, S. C. Donnellan, C. J. Raxworthy, J. A. Campbell, B. L. Blotto, P. Moler, R. C. Drewes, R. A. Nussbaum, J. D. Lynch, D. M. Green, and W. C. Wheeler. 2006. The Amphibian Tree of Life. Bulletin of the American Museum of Natural History 297: 1-370.

Frost, Darrel R. 2006. Amphibian Species of the World: an Online Reference. Version 4 (17 August 2006). Electronic Database accessible at: . American Museum of Natural History, New York, USA.

Goldingay, R., Newell, D. and Graham, M. 1999. The status of Rainforest Stream Frogs in north-eastern New South Wales: decline or recovery?. In: A. Campbell (ed.), Declines and Disappearances of Australian Frogs, pp. 64-71. Environment Australia.

Groombridge, B. (ed.) 1994. 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland.

Halliday, T. and Adler, C. (eds.). 2002. The new encyclopedia of reptiles and amphibians. Oxford University Press, Oxford.

Hero, J.-M and Fickling, S. 1996. Reproductive characteristics of female frogs from mesic habitats in Queensland. Memoirs of the Queensland Museum 39: 306.

Hines, H., Mahony, M. and McDonald, K. 1999. An assessment of frog declines in Wet Subtropical Australia. In: A. Campbell (ed.), Declines and Disappearances of Australian Frogs. Environment Australia.

Hines, H., Newell, D., Clarke, J., Hero, J.-M. & Meyer, E. 2004. Mixophyes iteratus. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. IUCN Red List of Threatened Species. Downloaded on 06 July 2007.

Ingram, G.J. and McDonald, K.R. 1993. An update on the decline of Queenslands frogs. In: D. Lunney and D. Ayers (eds), Herpetology in Australia: a diverse discipline, pp. 297-303. Royal Zoological Society of New South Wales, Mosman.

IUCN, Conservation International and NatureServe. 2006. Global Amphibian Assessment. Global Amphibian Assessment. Accessed on 08 December 2006.

Knowles, R., Hines, H.B., Thum, K., Mahony, M. and Cunningham, M. 1998. Oviposition of the barred-frogs (Mixophyes species) in southeastern Australia with implications for management. Unpublished abstract of a talk presented.

Lemckert, F. 1999. Impacts of selective logging on frogs in a forested area of northern New South Wales. Biological Conservation 89: 321-328.

Lemckert, F. 2002. The frog with the midas looks (4). Australian Nature 27: 62-69. Lemckert, F. and Brassil, T. 2000. Movements and habitat use of the endangered Giant Barred River Frog (Mixophyes iteratus) and the implications for its conservation in timber production forests. Biological Conservation 96: 177-184.

Lemckert, F.L. and Morse, R. 1999. Frogs in the timber production forests of the Dorrigo Escarpment in northern New South Wales: An inventory of species present and the conservation of threatened species. In: A. Campbell (ed.), Declines and Disappearances of Australian Frogs, pp. 72-80. Environment Australia, Canberra.

Mahony, M., Knowles, R. and Pattinson, L. 1997. 6. Gold-eyed Barred Frog, Mixophyes iteratus. In: H. Ehmann (ed.), Threatened Frogs of New South Wales: Habitats, Status and Conservation, pp. 78-83. Frog and Tadpole Study Group of New South Wales, Sydney South, Australia.

McDonald, K.R. 1991. Report of a workshop on declining frog populations in Queensland. Queensland National Parks and Wildlife Service.

Meyer, E., Hines, H. and Hero, J.-M. 2001. Giant Barred-Frog, Mixophyes iteratus. In: Wet Forest Frogs of South-east Queensland. Griffith University, Gold Coast.

Morrison, C. and Hero, J.-M. 2002. Geographic variation in life history characteristics of amphibians in mid-eastern Australia: reproductive traits. In: R. Natrass (ed.) Frogs in the Community - Proceedings of the Brisbane Conference 13-14 February 1999, pp. 40-48. Queensland Frog Society Inc.

NSW National Parks and Wildlife Service 1994. Results of vertebrate fauna surveys of north-east NSW Forests. In: North East Forests Biodiversity Study Report No. 3. NSW National Parks and Wildlife Service, unpublished, Hurtsville.

Obst, F.J., Richter, K. and Jacob, U. 1984. The Completely Illustrated Atlas of Reptiles and Amphibians for the Terrarium. T.F.H. Publication Inc., N.J., U.S.A.

Roelants, K., Gower, D. J., Wilkinson, M., Loader, S. P., Biju, S. D., Guillaume, K., Moiau, L. and Bossuyt, F. 2007. Global patterns of diversification in the history of modern amphibians. Proceedings of the National Academy of Sciences 104: 887-892.

Straughan, I.R. 1966. An analysis of species recognition and species isolation in certain Queensland frogs. PhD Thesis, University of Queensland.

Streatfeild, C. 1999. Spatial movements of Mixophyes iteratus and M. fasciolatus in southeast Queensland. Honours Thesis, Griffith University, Queensland.

Tyler, M.J. 1997. The Action Plan for Australian Frogs. Wildlife Australia, Canberra, ACT. White, A. 2000. The status of the Barred River Frogs Mixophyes balbus and Mixophyes iteratus in the Sydney Basin Region of New South Wales 1999-2000. In: Report for the NSW National Parks and Wildlife Service.

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