Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-28T00:06:27.107Z Has data issue: false hasContentIssue false

Does desiccation risk drive the distribution of juvenile cane toads (Bufo marinus) in tropical Australia?

Published online by Cambridge University Press:  01 March 2009

Travis Child
Affiliation:
School of Biological Sciences A08, University of Sydney, NSW 2006, Australia
Benjamin L. Phillips
Affiliation:
School of Biological Sciences A08, University of Sydney, NSW 2006, Australia
Richard Shine*
Affiliation:
School of Biological Sciences A08, University of Sydney, NSW 2006, Australia
*
1Corresponding author. Email: rics@bio.usyd.edu.au

Abstract:

Immediately after their transition from aquatic to terrestrial life, juveniles of many anuran species are restricted to the margins of natal ponds. Understanding the factors determining the duration of that pondside aggregation has direct management ramifications in the case of the invasive cane toad (Bufo marinus) in tropical Australia. Previous work suggests that dispersal confers biotic advantages (reduced risk of cannibalism, enhanced feeding opportunities) to juvenile toads, but desiccation risk constrains these small animals to the moist margins of the pond. If so, juvenile dispersal should be sensitive to fluctuating hydric conditions on a diel and seasonal cycle. We tested this prediction with field observations (monitoring of dispersal to and from the pond) and field experiments (manipulating hydric regimes). Our results support a dynamic model of juvenile distribution, with a primary role for temporal variations in desiccation risk as the primary factor driving dispersal. During the dry season, strong diel cycles in desiccation risk generate a ‘tidal’ flow of juveniles, dispersing out in the moist morning but retreating to the pond margins at midday. Dispersal rates were enhanced by artificial watering during the dry season, and by the onset of the wet season.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

LITERATURE CITED

BOWLER, D. E. & BENTON, T. G. 2005. Causes and consequences of animal dispersal strategies: relating individual behaviour to spatial dynamics. Biological Reviews 80:205225.CrossRefGoogle ScholarPubMed
BROWN, G. P. & SHINE, R. 2006. Why do most tropical animals reproduce seasonally? Testing hypotheses on an Australian snake. Ecology 87:133143.CrossRefGoogle Scholar
CHILD, T., PHILLIPS, B. L., BROWN, G. P. & SHINE, R. 2008a. The spatial ecology of cane toads (Bufo marinus) in tropical Australia: why do juvenile toads stay near the water? Austral Ecology 33:630640.CrossRefGoogle Scholar
CHILD, T., PHILLIPS, B. L. & SHINE, R. 2008b. Abiotic and biotic influences on the dispersal behaviour of juvenile cane toads (Bufo marinus) in tropical Australia. Journal of Experimental Zoology 309A:215224.CrossRefGoogle Scholar
COHEN, M. P. & ALFORD, R. A. 1993. Growth, survival and activity patterns of recently metamorphosed Bufo marinus. Wildlife Research 20:113.CrossRefGoogle Scholar
FREELAND, W. J. & KERIN, S. H. 1991. Ontogenetic alteration of activity and habitat selection by Bufo marinus. Wildlife Research 18:431443.CrossRefGoogle Scholar
GREENLEES, M. J., BROWN, G. P., WEBB, J. K., PHILLIPS, B. L. & SHINE, R. 2006. Effects of an invasive anuran (the cane toad Bufo marinus) on the invertebrate fauna of a tropical Australian floodplain. Animal Conservation 9:431438.CrossRefGoogle Scholar
HAGMAN, M. & SHINE, R. 2006. Spawning site selection by feral cane toads (Bufo marinus) at an invasion front in tropical Australia. Austral Ecology 31:551558.CrossRefGoogle Scholar
LEVER, C. 2001. The cane toad. The history and ecology of a successful colonist. Westbury Academic and Scientific Publishing, Otley. 230 pp.Google Scholar
MCKINNEY, M. L. & LOCKWOOD, J. L. 1999. Biotic homogenization: a few winners replacing many losers in the next mass extinction. Trends in Ecology and Evolution 14:450453.CrossRefGoogle ScholarPubMed
MOONEY, H. A. & CLELAND, E. E. 2001. The evolutionary impact of invasive species. Proceedings of the National Academy of Sciences of the United States of America 98:54465451.CrossRefGoogle ScholarPubMed
PHILLIPS, B. L. & SHINE, R. 2005. The morphology, and hence impact, of an invasive species (the cane toad, Bufo marinus): changes with time since colonisation. Animal Conservation 8:407413.CrossRefGoogle Scholar
PHILLIPS, B. L. & SHINE, R. 2006. Spatial and temporal variation in the morphology (and thus, predicted impact) of an invasive species in Australia. Ecography 29:205212.CrossRefGoogle Scholar
PHILLIPS, B. L., BROWN, G. P., GREENLEES, M., WEBB, J. K. & SHINE, R. 2007. Rapid expansion of the cane toad (Bufo marinus) invasion front in tropical Australia. Austral Ecology 32:169176.CrossRefGoogle Scholar
PIZZATTO, L. & SHINE, R. 2008. The behavioral ecology of cannibalism in cane toads (Bufo marinus). Behavioral Ecology and Sociobiology 63:123133.CrossRefGoogle Scholar
PIZZATTO, L., CHILD, T. & SHINE, R. 2008. Why be diurnal? Shifts in activity time enable young cane toads to evade cannibalistic conspecifics. Behavioral Ecology 19:990997.CrossRefGoogle Scholar
POUGH, F. H. & KAMEL, S. 1984. Post-metamorphic change in activity metabolism of anurans in relation to life-history. Oecologia 65:138144.CrossRefGoogle ScholarPubMed
PRAMUK, J. B. 2006. Phylogeny of South American Bufo (Anura: Bufonidae) inferred from combined evidence. Zoological Journal of the Linnean Society 146:407452.CrossRefGoogle Scholar
QUINN, G. P. & KEOUGH, M. J. 2002. Experimental design and data analysis for biologists. Cambridge University Press, Cambridge. 560 pp.CrossRefGoogle Scholar
ROSENZWEIG, M. L. 1991. Habitat selection and population interactions: the search for mechanism. American Naturalist 137:S5S28.CrossRefGoogle Scholar
SHINE, R. & BROWN, G. P. 2008. Adapting to the unpredictable: reproductive biology of vertebrates in the Australian wet-dry tropics. Invited review. Philosophical Transactions of the Royal Society Series B 363:363373.CrossRefGoogle Scholar
STRAYER, D. L., EVINER, V. T., JESCHKE, J. M. & PACE, M. L. 2006. Understanding the long-term effects of species invasions. Trends in Ecology and Evolution 21:645651.CrossRefGoogle ScholarPubMed
TAIGEN, T. L. & POUGH, F. H. 1981. Activity metabolism of the toad (Bufo americanus): ecological consequences of ontogenetic change. Journal of Comparative Physiology 144:247252.CrossRefGoogle Scholar
TOKESHI, M. 1992. Dynamics of distribution in animal communities: theory and analysis. Researches on Population Ecology 34:249273.CrossRefGoogle Scholar
WILLIS, K. J., ARAUJO, M. B., BENNETT, K. D., FIGUEROA-RANGEL, B., FROYD, C. A. & MEYERS, N. 2007. How can a knowledge of the past help to conserve the future? Biodiversity conservation and the relevance of long-term ecological studies. Philosophical Transactions of the Royal Society Series B 362:175186.CrossRefGoogle ScholarPubMed