Register      Login
Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats
Shopping Cart: ( empty )
You are here: Home > Journals > WR > WR05109
RESEARCH ARTICLE
Contents Vol 34(1)

Optimising bait-station delivery of fertility control agents to brushtail possum populations

Daniel M. Tompkins A C and David Ramsey B
+ Author Affiliations
- Author Affiliations

A Landcare Research, Private Bag 1930, Dunedin, New Zealand.

B Landcare Research, Private Bag 11 052, Palmerston North, New Zealand.

C Corresponding author. Email: tompkinsd@landcareresearch.co.nz

Wildlife Research 34(1) 67-76 https://doi.org/10.1071/WR05109
Submitted: 29 November 2005  Accepted: 19 December 2006   Published: 27 February 2007

Abstract

Introduced Australian brushtail possums (Trichosurus vulpecula) are a major pest in New Zealand. Alternatives to current management by trapping and poisoning are being actively explored. The most effective scenario for the deployment of fertility control vaccines is the use of bait stations to maintain possum populations at low densities following their initial knockdown from high densities using conventional control tools. However, three field trials that estimated population coverage achievable by differing station layouts using dyed baits have produced conflicting results. To assess optimal vaccine-delivery strategies adequately we need meaningful a priori expectations of the level of population coverage achievable by differing bait station layouts and densities. To this end, we collated data on field operations in which bait stations were used to deliver acute toxins for lethal control of possum populations and constructed an individual-based spatially explicit stochastic model to simulate encounter rates between possums and bait stations. The model provided a reasonable fit to the data from both the acute toxin operations and two of the three dyed-bait trials. The third trial likely overestimated typical possum movement distances. Simulating vaccine delivery in the model demonstrated that grid densities of 0.6 bait stations ha–1 are predicted to be optimal, and prefeeding may not be necessary. The model strongly indicates that the effective delivery of fertility control will not be limited by our ability to deliver vaccine baits to possums. However, the exact strategy to employ will depend on three key characteristics of any vaccine – its expense relative to existing tools, its longevity in the field, and its efficacy at reducing female breeding success.


Acknowledgements

Thanks go to Phil Cowan, Adrian Monks, Grant Norbury, Janine Duckworth, and three anonymous referees for constructive comments on the manuscript, and Christine Bezar for editorial assistance. This work was funded by the Foundation for Research, Science and Technology, contract number C09X0302.


References

Barlow, N. (1991). A spatially aggregated disease/host model for bovine Tb in New Zealand possum populations. Journal of Applied Ecology 28, 777–793.
| Crossref | GoogleScholarGoogle Scholar | Brockie R. E., Herritty P. J., Ward G. D., and Fairweather A. A. C. (1989). population study of Hawke’s Bay farmland possums, Trichosurus vulpecula. Ecology Division Report 26 (unpublished). Lower Hutt, Department of Scientific and Industrial Research.

Brockie, R. E. , Ward, G. D. , and Cowan, P. E. (1997). Possums (Trichosurus vulpecula) on Hawke’s Bay farmland: spatial distribution and population structure before and after a control operation. Journal of the Royal Society of New Zealand 27, 181–191.
Cowan P. E. (2000). Biological control of possums: prospects for the future. In ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial’. (Ed. T. L. Montague.) pp. 262–270. (Manaaki Whenua Press: Lincoln, New Zealand.)

Cowan P., and Clout M. (2000). Possums on the move: activity patterns, home ranges, and dispersal. In ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial’. (Ed. T. L. Montague.) pp. 24–34. (Manaaki Whenua Press: Lincoln, New Zealand.)

Efford M. (2000). Possum density, population structure, and dynamics. In ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial’. (Ed. T. L. Montague.) pp. 47–61. (Manaaki Whenua Press: Lincoln, New Zealand.)

Efford, M. (2004). Density estimation in live trapping studies. Oikos 106, 598–610.
| Crossref | GoogleScholarGoogle Scholar | Green W. Q. (1984). review of ecological studies relevant to management of the common brushtail possum. In ‘Possums and Gliders’. (Eds A. P. Smith and I. D. Hume.) pp. 483–499. (Surrey Beatty: Sydney.)

Green, W. Q. , and Coleman, J. D. (1986). Movement of possums (Trichosurus vulpecula) between forest and pasture in Westland, New Zealand: implications for bovine tuberculosis transmission. New Zealand Journal of Ecology 9, 57–69.
Henderson R. J., Morriss G. A., and Morgan D. R. (1997). The use of different types of toxic bait for sustained control of possums. In ‘Proceedings of the 50th New Zealand Plant Protection Conference’. pp. 382–390.

Hickling G. J., Thomas M. D., Grueber L. S., and Walker R. (1990). Possum movements and behaviour in response to self-feeding bait stations. Forest Research Institute Contract Report FEW 90/9 (unpublished). Forest Research, Rotorua, New Zealand.

Innes, J. , Nugent, G. , Prime, K. , and Spurr, E. B. (2004). Responses of kukupa (Hemiphaga novaeseelandiae) and other birds to mammal pest control at Motatau, Northland. New Zealand Journal of Ecology 28, 73–81.
Montague M. (2000). ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial.’ (Manaaki Whenua Press: Lincoln, New Zealand.)

Morgan, D. R. (1981). Development of a tracer technique for monitoring bait acceptance in brush-tailed possum (Trichosurus vulpecula Kerr) populations. New Zealand Journal of Forestry Science 11, 271–277.
Morgan D., and Hickling G. (2000). Techniques used for poisoning possums. In ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial’. (Ed. T. L. Montague.) pp. 143–153. (Manaaki Whenua Press: Lincoln, New Zealand.)

Paterson, B. M. , Morris, R. S. , Weston, J. , and Cowan, P. E. (1995). Foraging and denning patterns of brushtail possums, and their possible relationship to contact with cattle and the transmission of bovine tuberculosis. New Zealand Veterinary Journal 43, 281–288.
| PubMed | Pracy L. T. (1964). Opossum control in exotic forests. New Zealand Forest Service Report (unpublished). NZFS, Wellington, New Zealand.

Ramsey, D. (2005). Population dynamics of brushtail possums subject to fertility control. Journal of Applied Ecology 42, 348–360.
| Crossref | GoogleScholarGoogle Scholar | Thomas M. D. (1992). Evaluation of 1080 bait feeders for possum control in small forest reserves. Forest Research Institute Contract Report FEW 92/26 (unpublished). Forest Research Institute, Rotorua, New Zealand.

Thomas M. D. (1994). Possum control in native forest using sodium monofluoroacetate (1080) in bait stations. In ‘Proceedings of the 47th New Zealand Plant Protection Conference’. pp. 107–111.

Thomas M. D., and Fitzgerald H. (1994). Bait-station spacing for possum control in forest. Landcare Research Contract Report LC9394/118 (unpublished). Landcare Research, Lincoln, New Zealand.

Thomas M. D., and Meenken D. (1995). Comparison of ground-laid 1080 paste baits and 1080 cereal baits in bait stations for possum control on farmland. Landcare Research Contract Report LC9596/36 (unpublished). Landcare Research, Lincoln, New Zealand.

Thomas M. D., Mason J., and Briden K. W. (1997). Optimising the use of bait stations for possum control in native forest. Landcare Research Contract Report LC9697/45 (unpublished). 15 pp.

Warburton, B. , and Thomson, C. (2002). Comparison of three methods for maintaining possums at low density. Science for Conservation (Wellington) 189,[Department of Conservation: Wellington, New Zealand.]
Ward G. D. (1978). Habitat use and home range of radio-tagged oppossums, Trichosurus vulpecula (Kerr) in New Zealand lowland forest. In ‘The Ecology of Arboreal Folivores’. (Ed. G. G. Montgomery.) pp. 267–287. (Smithsonian Institution Press: Washington, DC.)