Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Australian Journal of Zoology Australian Journal of Zoology Society
Evolutionary, molecular and comparative zoology
RESEARCH ARTICLE

Population monitoring of the vulnerable wallum sedge frog (Litoria olongburensis) in north-eastern New South Wales

B. D. Lewis A B and R. L. Goldingay A
+ Author Affiliations
- Author Affiliations

A School of Environmental Science and Management, Southern Cross University, Lismore, NSW 2480, Australia.

B Corresponding author. Email: lewisecological@yahoo.com.au

Australian Journal of Zoology 53(3) 185-194 https://doi.org/10.1071/ZO03063
Submitted: 5 December 2003  Accepted: 8 April 2005   Published: 16 June 2005

Abstract

The literature on the population ecology of Australian frogs provides relatively few accounts of population monitoring. This has hampered our ability to understand how frog populations respond to dynamic rainfall patterns and to determine the stability of populations of threatened frog species. We conducted biannual monitoring of the wallum sedge frog (Litoria olongburensis) along transects at 10 sites over a 4-year period (1996–2000). We recorded six environmental parameters to assess their influence on our population indices. Monitoring of transects indicated that populations were rarely stable and fluctuated from year to year. Counts of adults were negatively influenced by rain during the previous day but positively influenced by rain during the previous week. This suggests that timing of recent rainfall has a differing influence on habitat use by adult frogs. Counts of adults were also significantly influenced by site and census period. Numbers of juveniles were influenced by rain during the previous three months, which may suggest that successful recruitment depends on higher water levels in the sedge swamps. Counts of juveniles were also significantly influenced by census period. Our analysis reveals that, after controlling for the influence of rainfall, the number of adult frogs per census varied between 10 and 20 per transect. The number of juveniles varied between 5 and 15 per transect per census. We conclude that the wallum sedge frog across the geographic range of our sites was not in decline during our monitoring period. In light of our findings we provide a review on population monitoring of Australian frogs.


Acknowledgments

The following people are thanked for their involvement and assistance throughout the project: David Charley, Brian McLachlan, Bob Moffat and Lance Tarvey of Lismore District NPWS for arranging access into restricted areas of conservation reserves and Craig Taylor (SCU) for assistance in establishing sites. Mark Graham and David Rohweder assisted in the field on several occasions. This manuscript has benefited from the comments of David Rohweder and an anonymous referee. We thank Dr Lyndon Brooks for assistance with the statistical analysis.


References

Bamford, M. J. (1992). The impact of fire and increasing time after fire upon Heleioporus eyrie, Limnodynastes dorsalis and Myobatrachus gouldii (Anura: Leptodactylidae) in Banksia woodland near Perth, Western Australia. Wildlife Research 19, 169–178.
Barker J., Grigg G., and Tyler M. (1995). ‘A Field Guide to Australian Frogs.’ (Surrey Beatty: Sydney.)

Berven, K. A. (1995). Population regulation in the wood frog, Rana sylvatica, from three diverse geographic localities. Australian Journal of Ecology 20, 385–392.
Cogger H. G. (1995). ‘Reptiles and Amphibians of Australia.’ 5th edn. (Reed Books: Sydney.)

Driscoll, D. A. , and Roberts, D. J. (1997). Impact of fuel-reduction burning on the frog Geocrinia lutea in southwest Western Australia. Australian Journal of Ecology 22, 334–339.
Ehmann H. (1997). Wallum sedge frog. In ‘Threatened Frogs of New South Wales: Habitats, Status and Conservation’. (Ed. H. Ehmann.) pp. 182–187. (FATS Group Publication: Sydney.)

Goldingay, R. , and Lewis, B. (1999). Development of a conservation strategy for the green and golden bell frog in the Illawarra Region of NSW. Australian Zoologist 31, 376–387.
Goldingay R., Newell D., and Graham M. (1999). Status of rainforest stream frogs in north-eastern New South Wales: decline or recovery? In ‘Declines and Disappearances of Australian Frogs’. (Ed. A. Campbell.) pp. 64–71. (Environment Australia: Canberra.)

Griffith, S. J. , Bale, C. , Adam, P. , and Wilson, R. (2003). Wallum and related vegetation on the NSW north coast: description and phytosociological analysis. Cunninghamia 8, 202–252.
Hines H., Mahony M., and McDonald K. (1999). An assessment of frog declines in wet subtropical Australia. In ‘Declines and Disappearances of Australian Frogs’. (Ed. A. Campbell.) pp. 44–63. (Environment Australia: Canberra.)

Ingram, G. J. , and Corben, C. J. (1975). The frog fauna of North Stradbroke Island, with comments on the ‘acid’ frogs of the wallum. Proceedings of the Royal Society of Queensland 86(9), 49–54.
Lewis B. D. (1996). A distribution and habitat assessment of three threatened frog species; Litoria aurea, Litoria olongburensis, Crinia tinnula in northern NSW. B.Sc.(Graduate) Thesis, Southern Cross University, Lismore.

McDonald K., and Alford R. (1999). A review of declining frogs in north Queensland. In ‘Declines and Disappearances of Australian Frogs’. (Ed. A. Campbell.) pp. 14–22. (Environment Australia: Canberra.)

National Parks and Wildlife Service (1997). Bundjalung National Park: plan of management. NSW National Parks and Wildlife Service, Lismore.

National Parks and Wildlife Service (1998). Fire management plan: Broadwater National Park. NSW National Parks and Wildlife Service, Lismore.

National Parks and Wildlife Service (2000). Fire management plan: Tyagarah Nature Reserve. NSW National Parks and Wildlife Service, Lismore.

Osborne, W. S. , Littlejohn, M. J. , and Thomson, S. A. (1996). Former distribution and apparent disappearance of the Litoria aurea complex from the Southern Tablelands of New South Wales and the Australian Capital Territory. Australian Zoologist 30, 190–198.
Osborne W., Hunter D., and Hollis G. (1999). Population declines and range contraction in Australian alpine frogs. In ‘Declines and Disappearances of Australian Frogs’. (Ed. A. Campbell.) pp. 145–157. (Environment Australia: Canberra.)

Pechmann, J. H. K. , Scott, D. E. , Semlitsch, R. D. , Caldwell, J. P. , Vitt, L. J. , and Gibbons, J. W. (1991). Declining amphibian populations: the problem of separating human impacts from natural fluctuations. Science 253, 892–895.
Robinson M. (1995). ‘A Field Guide to Frogs of Australia: From Port Augusta to Fraser Island Including Tasmania.’ (Australian Museum/Reed Publications: Sydney.)

Snijders T. A. B., and Bosker R. J. (1999). ‘Multilevel Analysis: An Introduction to Basic and Advanced Multilevel Modelling.’ (Sage Publishers: London.)

Tyler M. J. (1994). ‘Australian Frogs: a Natural History.’ (Reed Books: Sydney.)

White A. W. (1993). Ecological and behavioural observations on populations of the toadlets Pseudophryne bibronii and Pseudophryne coriacea on the central coast of New South Wales. In ‘Herpetology in Australia: A Diverse Discipline’. (Eds D. Lunney and D. Ayers.) pp. 139–149. (Surrey Beatty: Sydney.)

White A. W. (1995). Schedule 12 species: Amphibian descriptions. In ‘Environmental and Fauna Impact Statement: Volume C’. (Ed. Australian Museum Business Services.) pp. 39–41. (State Forests of New South Wales: Sydney.)

Williamson, I. , and Bull, C. M. (1996). Population ecology of the Australian frog Crinia signifera: adults and juveniles. Wildlife Research 23, 249–266.