Relative effectiveness of trapping and hand-capture for controlling invasive cane toads (Rhinella marina)

ABSTRACT

Management of invasive vertebrates is a crucial component of conservation. Management strategies should increase the chance of removal of every individual, by exploiting behavioural characteristics, and by increasing the period over which removal occurs. For example, traps can operate automatically over long periods, and often include attractants to increase captures. Management strategies for the invasive cane toad (Rhinella marina) in Australia include hand capture and trapping adult individuals (toads are attracted to an acoustic lure, and to insects attracted to a light, also on the lure). We used capture-mark-recapture analysis to compare the efficacy of trapping and hand capturing cane toads over 10 weeks, in Townsville, Australia. We trapped 7.1%–22.4% of the estimated population per week, and hand captured 1.7%–6% of the estimated population per week. Trapping was more efficient than hand capture in our regime; overall, more toads were caught per trapping man-hour than per hand-capture hour. Traps attract toads and maximise the period over which removal occurs; thus, the probability of removal for each toad was higher than by hand capture. Because hand capture and trapping seemed to remove different toads, a combination of these methods may work well.

KEYWORDS:

• Rhinella marina
• cane toad
• trapping
• acoustic lure
• invasive
• pest management

Acknowledgments

We thank M. Wuth, C. Meek, G. Charlton, D. Tegtmeier, A. Chazan and L. Edwards for assistance with data collection, and 3 anonymous reviewers for their useful feedback that improved the manuscript. We also thank Animal Control Technologies Australia (ACTA) for providing equipment for the trapping regime. All procedures performed were in accordance with the ethical standards of the institution at which the studies were conducted, the project was approved by the James Cook University Animal Ethics Committee (A2046).

Disclosure statement

The authors have no conflicts of interest to declare.

Additional information

Funding

Australian Research Council [linkage grant number LP10020032].