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RESEARCH ARTICLE
Contents Vol 36(1)

Comparisons through time and space suggest rapid evolution of dispersal behaviour in an invasive species

Ross A. Alford A , Gregory P. Brown B , Lin Schwarzkopf A , Benjamin L. Phillips B and Richard Shine B C
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A School of Marine and Tropical Biology, James Cook University, Townsville, Qld 4811, Australia.

B School of Biological Sciences A08, University of Sydney, NSW 2006, Australia.

C Corresponding author. Email: rics@bio.usyd.edu.au

Wildlife Research 36(1) 23-28 https://doi.org/10.1071/WR08021
Submitted: 5 February 2008  Accepted: 2 June 2008   Published: 21 January 2009

Abstract

During a biological invasion, we expect that the expanding front will increasingly become dominated by individuals with better dispersal abilities. Over many generations, selection at the invasion front thus will favour traits that increase dispersal rates. As a result of this process, cane toads (Bufo marinus) are now spreading through tropical Australia about 5-fold faster than in the early years of toad invasion; but how have toads changed to make this happen? Here we present data from radio-tracking of free-ranging cane toads from three populations (spanning a 15-year period of the toads’ Australian invasion, and across 1800 km). Our data reveal dramatic shifts in behavioural traits (proportion of nights when toads move from their existing retreat-site to a new one, and distance between those successive retreat-sites) associated with the rapid acceleration of toad invasion. Over a maximum period of 70 years (~50 generations), cane toads at the invasion front in Australia apparently have evolved such that populations include a higher proportion of individuals that make long, straight moves.


Acknowledgements

We thank the Council of Nature Conservation Ministers, the Commonwealth Scientific and Industrial Research Organisation, and the Australian Research Council for funding. The impetus to prepare this paper came from the Caughley symposium of the Australian Wildlife Management Society, sponsored by the Australian Academy of Science. We thank them, and the participants in that meeting, for their support and the opportunities for discussion.


References

Alford R. A. , Cohen M. P. , Crossland M. R. , Hearnden M. N. , James D. , and Schwarzkopf L. (1995). Population biology of Bufo marinus in northern Australia. In ‘Wetland Research in the Wet–Dry Tropics of Australia’. (Ed. M. Finlayson.) pp. 173–181. Supervising Scientist Report No. 101. (Office of the Supervising Scientist: Canberra.)

Brown, G. P. , Phillips, B. L. , Webb, J. K. , and Shine, R. (2006). Toad on the road: use of roads as dispersal corridors by cane toads (Bufo marinus) at an invasion front in tropical Australia. Biological Conservation 133, 88–94.
| Crossref | GoogleScholarGoogle Scholar | Caughley G. (1977). ‘Analysis of Vertebrate Populations.’ (John Wiley & Sons: Chichester.)

Lee, C. E. (2002). Evolutionary genetics of invasive species. Trends in Ecology & Evolution 17, 386–391.
| Crossref | GoogleScholarGoogle Scholar | Lever C. (2001). ‘The Cane Toad. The History and Ecology of a Successful Colonist.’ (Westbury Scientific Publishing: Otley, West Yorkshire.)

Mehta, C. R. (1994). The exact analysis of contingency tables in medical research. Statistical Methods in Medical Research 3, 135–156.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed | Sax D. F. , Stachowicz J. J. , and Gaines S. D. (Eds) (2005). ‘Species Invasions: Insights Into Ecology, Evolution, and Biogeography.’ (Sinauer Associates: Sunderland, MA.)

Schwarzkopf, L. , and Alford, R. A. (1996). Desiccation and shelter-site use in a tropical amphibian: comparing toads with physical models. Functional Ecology 10, 193–200.
| Crossref | GoogleScholarGoogle Scholar | Zar J. (1999). ‘Biostatistical Analysis.’ (Prentice-Hall: New Jersey.)