Movement patterns of southern bell frogs (Litoria raniformis) in response to flooding
Skye Wassens A B , Robyn J. Watts A , Amy Jansen A and David Roshier AA Institute for Land, Water and Society, School of Environmental Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
B Corresponding author. Email: swassens@csu.edu.au
Wildlife Research 35(1) 50-58 https://doi.org/10.1071/WR07095
Submitted: 17 July 2007 Accepted: 23 January 2008 Published: 17 March 2008
Abstract
Within the semiarid regions of New South Wales, Australia, the endangered southern bell frog (Litoria raniformis) occupies a landscape that is characterised by unpredictable rainfall and periodic flooding. Limited knowledge of the movement and habitat-occupancy patterns of this species in response to flood events has hampered conservation efforts. We used radio-tracking to assess changes in movement patterns and habitat occupancy of L. raniformis (n = 40) over three different periods (November, January and April/May) that coincided with the flooding, full capacity and subsequent drying of waterbodies within an irrigation landscape. We assessed (1) the use of permanent and ephemeral habitats in response to flooding and drying and (2) distances moved, turning angles and dispersion of frogs during wetland flooding, full capacity and drying. Individuals remained in permanent waterbodies in November but had abandoned these areas in favour of flooded ephemeral waterbodies by January. As the ephemeral waterbodies dried, radio-tracked individuals moved back into permanent waterbodies. The movement patterns of radio-tracked individuals were significantly different in the three radio-tracking periods, but did not differ significantly between sexes. Individuals moved significantly greater distances over 24 h, in straighter lines and movements were more dispersed while they occupied ephemeral waterbodies during January than when they occupied permanent waterbodies during November and April/May. Local weather conditions did not influence movement patterns when all three tracking periods were modelled together using a single linear stepwise regression. The dynamic distribution of habitat patches over space and time, combined with changing patterns of resource utilisation and movement of L. raniformis, highlights the importance of incorporating both permanent and ephemeral habitat patches into conservation plans. Reductions in flood frequency and extent of ephemeral wetlands due to modified flooding regimes have the capacity to limit dispersal of this species, even when permanent waterbodies remain unchanged.
Acknowledgements
This study was funded by the CRC for Sustainable Rice Production and the Murray–Darling Basin Commission. S. Wassens was supported by an Australian Postgraduate Award. A. Robertson provided comments on early drafts of this manuscript. We are grateful for the helpful comments of two anonymous referees. G. Pyke and W. Osborne assisted in establishing survey techniques. S. Patmore, S. Sass, and C. Coombs assisted with fieldwork. We thank land managers for giving us access to the study sites. This research was conducted under NSW National Parks and Wildlife Service Licence (S3053). Ethics approval was granted by Charles Sturt University Animal Care and Ethics Committee (01/034).
Acosta, M. , Mugica, L. , Mancina, C. , and Ruiz, X. (1996). Resource partitioning between glossy and white ibises in a rice field systems in south central Cuba. Colonial Waterbirds 19, 65–72.
| Crossref | GoogleScholarGoogle Scholar |
Arthington, A. H. , Balcombe, S. R. , Wilson, G. A. , Thoms, M. C. , and Marshall, J. (2005). Spatial and temporal variation in fish-assemblage structure in isolated waterholes during the 2001 dry season of an arid-zone floodplain river, Cooper Creek, Australia. Marine and Freshwater Research 56, 25–35.
| Crossref | GoogleScholarGoogle Scholar |
Christy, M. T. , and Dickman, C. R. (2002). Effects of salinity on tadpoles of the green and golden bell frog (Litoria aurea). Amphibia-Reptilia 23, 1–11.
| Crossref | GoogleScholarGoogle Scholar |
Hutchinson, M. F. , McIntyre, S. , Hobbs, R. J. , Stein, J. L. , Garnett, S. , and Kinloch, J. (2005). Integrating a global agro-climatic classification with bioregional boundaries in Australia. Global Ecology and Biogeography 14, 197–212.
| Crossref | GoogleScholarGoogle Scholar |
Lane, S. J. , and Fujioka, M. (1998). The impact of changes in irrigation practices on the distribution of foraging egrets and herons (Ardeidae) in the rice fields of central Japan. Biological Conservation 83, 221–230.
| Crossref | GoogleScholarGoogle Scholar |
Rittenhouse, T. A. G. , and Semlitsch, R. D. (2006). Grasslands as movement barriers for a forest-associated salamander: migration behaviour of adult and juvenile salamanders at a distinct habitat edge. Biological Conservation 131, 14–22.
| Crossref | GoogleScholarGoogle Scholar |
Robinson, M. (1993). A record of the warty swamp frog, Litoria raniformis feeding underwater. Herpetofauna 23, 39.
Rothermel, B. B. , and Semlitsch, R. D. (2002). An experimental investigation of landscape resistance of forest versus old-field habitats to emigrating juvenile amphibians. Conservation Biology 16, 1324–1332.
| Crossref | GoogleScholarGoogle Scholar |
Saunders, D. A. , Hobbs, R. J. , and Margules, C. R. (1991). Biological consequences of ecosystem fragmentation: a review. Conservation Biology 5, 18–32.
| Crossref | GoogleScholarGoogle Scholar |
Schabetsberger, R. , Jehle, R. , Maletzky, A. , Pesta, J. , and Sztatecsny, M. (2004). Delineation of terrestrial reserves for amphibians: post-breeding migrations of Italian crested newts (Triturus c. carnifex) at high altitude. Biological Conservation 117, 95–104.
| Crossref | GoogleScholarGoogle Scholar |
Schwarzkopf, L. , and Alford, R. A. (2002). Nomadic movements in tropical toads. Oikos 96, 492–506.
| Crossref | GoogleScholarGoogle Scholar |
Seebacher, F. , and Alford, R. A. (2002). Shelter microhabitats determine body temperature and dehydration rates of a terrestrial amphibian (Bufo marinus). Journal of Herpetology 36, 69–75.
Sinsch, U. (1990). Migration and orientation in anuran amphibians. Ethology Ecology and Evolution 2, 65–79.
Snodgrass, J. W. , Komoroski, M. J. , Bryan, A. L. , and Burger, J. (2000). Relationships among isolated wetland size, hydroperiod, and amphibian species richness: implications for wetland regulations. Conservation Biology 14, 414–419.
| Crossref | GoogleScholarGoogle Scholar |
Wahbe, T. R. , and Bunnell, F. L. (2001). Preliminary observations on movements of tailed frog tadpoles (Ascaphus truei) in streams through harvested and natural forests. Northwest Science 75, 77–83.
Ward, J. V. , and Stanford, J. A. (1995). Ecological connectivity in alluvial river ecosystems and its disruption by flow regulation. Regulated Rivers 11, 105–119.
| Crossref | GoogleScholarGoogle Scholar |
Wassens, S. , Roshier, D. A. , Watts, R. J. , and Robertson, A. I. (2007). Spatial patterns of a southern bell frog (Litoria raniformis) population in an agricultural landscape. Pacific Conservation Biology 13, 104–110.
Whiteman, H. H. , Wissinger, S. A. , and Bohonak, A. J. (1994). Seasonal movement patterns in a sub-alpine population of the tiger salamander, Ambystoma tigrinum nebulosum. Canadian Journal of Zoology – Revue Canadienne De Zoologie 72, 1780–1787.
