Olongburra Frog

Population and Distribution Litoria olongburensis is distributed from L. Woongeel, Fraser Is., s. to near Woolgoolga including Bribie, Moreton and Stradbroke Is., s.e. Qld (Hines et al. 1999). The area of occupancy of the species is approximately 9000 km2 (map in Hines et al. 1999). There is no information on population size, structure or dynamics (Hines et al. 1999). Litoria olongburensis exhibits genetic structuring on a north-south gradient (James 1996). Northern NSW, North Stradbroke Is., Moreton Is. and Cooloola-Fraser populations are each genetically differentiated and significantly divergent from each other (James 1996). Populations occurring on these islands should be considered separate management units or demographically independent sets of populations due to their insular nature (James 1996). Litoria olongburensis is known from a number of mainland and island conservation reserves and public lands in Qld and NSW. In Qld, L. olongburensis has been recorded from Great Sandy, Cooloola, Noosa, Bribie Is., Moreton Is. and Blue L. NP, Beerwah, Tuan and Toolara SF, crown lands north of Coolum and West of Marcoola (Sunshine Coast) and North Stradbroke Is. (Tyler 1997). In NSW L. olongburensis has been recorded from Broadwater, Bundjalung, and Yuraygir NP, Tyagarah and Broken Head Nature Reserves, crown lands south of Yamba and west of Brunswick Heads, Cape Byron Headland Reserve. Also recorded outside of these areas in NSW: west of Tyagarah Nature Reserve, Round Mountain near L. Cudgen, Jali Council land at Newrybar, Cobaki L., Hastings Point (Tyler 1997) and in the Gold Coast Airport land on the NSW � Qld border (Hero pers. comm.).HabitatLitoria olongburensis is restricted to coastal lowlands and sand islands where there are low nutrient soils or deep sands (Hines et al. 1999). Vegetation types typical of these environments include heathland, Melaleuca swamp, sedgeland and Banksia woodland (Hines et al. 1999). It occurs in low pH waters characteristic of wallum environments, along flowing creeks, in marshy or swampy habitats (usually temporary or semi-permanent) and their connecting channels, and coastal freshwater lakes, including perched lakes with deep water (often permanent) (Liem & Ingram 1977; James 1996; Ehmann 1997). During wet periods these swamps are heavily inundated and L. olongburensis are found clinging to emergent vegetation (grasses, reeds and Bungwall Fern E. Meyers pers. comm.) During dry periods individuals may be found at the base of sedges, grass clumps and/or Bungwall Fern in the same swamps (E. Meyer pers. comm.). Ingram and Corben (1975) termed L. olongburensis an �acid� frog as this species is confined to sandy heaths and their acidic water. Non breeding habitat not known.

ReproductionLimited information is available on the breeding biology of the species. Ehmann (1997) recorded males calling in spring, summer and early autumn at night and by day when swamps were rising or ample water was available. Litoria olongburensis mainly breeds following heavy rain in perched swamps, amidst sedges, grasses and/or Bungwell Fern (Blechnum indicum) in still water 0.5-1.5 m deep (E. Meyer pers. comm.). The wallum waters in which the species breeds are typically heavily tanin-stained, highly acidic and generally dillute (E. Meyer pers. comm.). Eggs are attached to grasses and sedges and larvae are nektonic in form and dwell amongst reeds and grasses in water 0.5-1.5 m deep (E. Meyer pers. comm.). Fish are largely absent from habitat occupied by the species (E. Meyer pers. comm.). FeedingLarval L. olongburensis appear to subsist on biofilm enveloping reeds (James 1996; E. Meyers pers. comm.). Adult diet is unknown.Invasive species:Weed invasion is a potentially threatening process (Hines et al. 1999). Competition from invading frog species and predation from introduced fish (ie. Gambusia holbrooki) have been identified as potentially threatening processes (Ehmann 1997; Hines et al. 1999) however remain untested.MovementsDispersal abilities and the frequency or likelihood of colonisation events are not known. However, its use of recently created or rehabilitated sites for reproduction suggests that they are quite successful colonists provided there is a natural corridor to aid dispersal (James 1996). The disjunct distribution of the species is associated with considerable genetic structuring between populations (James 1996). Historically, though, dispersal between isolated habitats almost certainly involved short term opportunistic movement across areas during wet periods and long-term population dispersal along suitable corridors (coastal swamps and wallum plains) (James 1996).

Populations appear to be relatively stable in protected habitat, however this species is at risk from continuing loss of habitat through clearing for agriculture, pine plantations, housing and infrastructure such as canal development, drainage projects and transport corridors (Ingram & McDonald 1993; Hines et al. 1999). Melaleuca forest and heathland are particularly threatened and have been extensively cleared since 1974 (Catterall and Kingston 1993) suggesting an extensive loss of habitat. Other threats include habitat degradation through changes in hydrological regimes, increased nutrients or sediments, weed invasion, inappropriate fire management, competition from invading frog species and predation from introduced fish (Hines et al. 1999).

The wallum sedge frog (Litoria olongburensis), also known as the Olongburra frog or the sharp-snouted reed frog, is a species of frog that is endemic to Australia. Varying in color from brown to dark green it inhabits the thick and often acidic marshes of the Wallum along the coast of Queensland and New South Wales. Mating season comes in early spring, often after heavy rainfalls. Females attach their eggs to grasses and sedges. Their call is high pitched and follows a "creeeek... crik" pattern.

Its natural habitats are subtropical or tropical swamps, wallum swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, and intermittent freshwater marshes.

The species is considered vulnerable with there being about 10,000–50,000 such frogs in the wild. Despite conservation efforts, the population continues to decrease. Loss of habitat, invasive plants, and disease (most notably chytrid fungus) are contributing to the loss of population.