Dietary changes in response to population reduction in the possum Trichosurus vulpecula in New Zealand
Peter J. Sweetapple A C , Wendy A. Ruscoe A B and Graham Nugent A
+ Author Affiliations
- Author Affiliations
A Landcare Research, PO Box 69040, Lincoln 7640, New Zealand.
B Present address: Institute of Applied Ecology, University of Canberra, Bruce, ACT 2617, Australia.
C Corresponding author. Email: sweetapplep@landcareresearch.co.nz
Wildlife Research 40(7) 561-569 https://doi.org/10.1071/WR13118
Submitted: 27 June 2013 Accepted: 20 November 2013 Published: 28 January 2014
Abstract
Context: Efforts to protect or restore degraded plant communities by population control of invasive herbivores frequently fail to achieve their goals.
Aims: We seek to quantify changes in diet of an introduced herbivore, the brushtail possum (Trichosurus vulpecula), following population control, and determine how these may contribute to variable responses in plant condition.
Methods: Stomach contents of possums from five areas of indigenous forest in northern New Zealand were analysed to measure diet before and after the application of possum control.
Key results: The contribution of fruit, and foliage of some early successional forest species, to total possum diet increased up to 27-fold following possum population control. This was accompanied by declines in consumption of the main pre-control possum foods (foliage from common canopy trees). Dietary changes were a combination of an immediate response to control (1 year) and a strengthening of these initial changes with increasing time since control.
Conclusions: Possums in the study areas changed diet following population control, from a diet dominated by foliage of common canopy tree species to one dominated by fruits, and foliage of uncommon early successional plants. Pest control instantaneously increased the per capita availability of all foods, and probably permitted absolute increases in some foods through plant recovery, enabling possums to substitute scarce, high-preference foods for abundant but less preferred canopy foliage.
Implications: Following control of a pest herbivore, dietary changes reduce benefits for the most vulnerable preferred plant foods, but enhance benefits for less favoured plants. Intense pest control can permit some recovery of highly preferred foods, despite increased per capita consumption of these foods by survivors of control.
Additional keywords: diet, impact mitigation, invasive herbivore, population control.
References
Alterio, N. (1996). Secondary poisoning of stoats (Mustela erminea), feral ferrets (Mustela furo), and feral house cats (Felis catus) by the anticoagulant poison, brodifacoum. New Zealand Journal of Zoology 23, 331–338.| Secondary poisoning of stoats (Mustela erminea), feral ferrets (Mustela furo), and feral house cats (Felis catus) by the anticoagulant poison, brodifacoum.Crossref | GoogleScholarGoogle Scholar |
Augustine, D. J., and McNaughton, S. J. (1998). Ungulate effects on the functional species composition of plant communities: herbivore selectivity and plant tolerance. The Journal of Wildlife Management 62, 1165–1183.
| Ungulate effects on the functional species composition of plant communities: herbivore selectivity and plant tolerance.Crossref | GoogleScholarGoogle Scholar |
Bellingham, P. J., Stewart, G. H., and Allen, R. B. (1999). Tree species richness and turnover throughout New Zealand forests. Journal of Vegetation Science 10, 825–832.
| Tree species richness and turnover throughout New Zealand forests.Crossref | GoogleScholarGoogle Scholar |
Brockie, R. (1992). ‘A Living New Zealand Forest.’ (David Bateman: Auckland, New Zealand.)
Codron, D., Lee-Thorp, J. A., Sponheimer, M., and Codron, J. (2007). Nutritional content of savannah plant foods: implications for browser/grazer models of ungulate diversification. European Journal of Wildlife Research 53, 100–111.
| Nutritional content of savannah plant foods: implications for browser/grazer models of ungulate diversification.Crossref | GoogleScholarGoogle Scholar |
Coleman, J. D., Green, W. Q., and Polson, J. G. (1985). Diet of brushtail possums over a pasture–alpine gradient in Westland, New Zealand. New Zealand Journal of Ecology 8, 21–35.
Coomes, D. A., Allen, R. B., Forsyth, D. M., and Lee, W. G. (2003). Factors preventing the recovery of New Zealand forests following control of invasive deer. Conservation Biology 17, 450–459.
| Factors preventing the recovery of New Zealand forests following control of invasive deer.Crossref | GoogleScholarGoogle Scholar |
Coomes, D. A., Alan, M., and Bee, J. (2006). Animal control and recovery. In ‘Biological Invasions in New Zealand’. (Eds R. B. Allen and W. G. Lee.) pp. 339–353. Ecological Studies 186. (Springer: Berlin.)
Courchamp, F., Chapuis, J., and Pascal, M. (2003). Mammal invaders on islands: impact, control and control impact. Biological Reviews of the Cambridge Philosophical Society 78, 347–383.
| Mammal invaders on islands: impact, control and control impact.Crossref | GoogleScholarGoogle Scholar | 14558589PubMed |
Cowan, P. E. (1990). Fruits, seeds, and flowers in the diet of brushtail possums, Trichosurus vulpecula, in lowland podocarp/broadleaf forest, Orongorongo Valley, New Zealand. New Zealand Journal of Zoology 17, 549–566.
| Fruits, seeds, and flowers in the diet of brushtail possums, Trichosurus vulpecula, in lowland podocarp/broadleaf forest, Orongorongo Valley, New Zealand.Crossref | GoogleScholarGoogle Scholar |
Cowan, P. E. (1991). Effects of possums on fruiting of nikau. New Zealand Journal of Botany 29, 91–93.
| Effects of possums on fruiting of nikau.Crossref | GoogleScholarGoogle Scholar |
Cowan, P. E. (2005). Brushtail possum. In ‘The Handbook of New Zealand Mammals’. 2nd edn. (Ed. C. M. King.) pp. 56–80. (Oxford University Press: Melbourne.)
Cowan, P. E., and Waddington, D. C. (1990). Suppression of fruit production of the endemic forest tree, Elaeocarpus dentatus, by introduced marsupial brushtail possums, Trichosurus vulpecula. New Zealand Journal of Botany 28, 217–224.
| Suppression of fruit production of the endemic forest tree, Elaeocarpus dentatus, by introduced marsupial brushtail possums, Trichosurus vulpecula.Crossref | GoogleScholarGoogle Scholar |
Cribari-Neto, F., and Zeileis, A. (2010). Beta regression in R. Journal of Statistical Software 34, 1–24.
Dasilva, G. L. (1992). The western black-and-white colobus (Colobus polykomos polykomos) as a low energy strategist: activity budgets, energy expenditure and energy intake. Journal of Animal Ecology 61, 79–91.
| The western black-and-white colobus (Colobus polykomos polykomos) as a low energy strategist: activity budgets, energy expenditure and energy intake.Crossref | GoogleScholarGoogle Scholar |
Duncan, R. P., Holland, E. P., Pech, R. P., Barron, M., Nugent, G., and Parkes, J. P. (2011). The relationship between possum density and browse damage on kamahi in New Zealand forests. Austral Ecology 36, 858–869.
| The relationship between possum density and browse damage on kamahi in New Zealand forests.Crossref | GoogleScholarGoogle Scholar |
Fitzgerald, A. E. (1976). Diet of the opossum Trichosurus vulpecula (Kerr) in the Orongorongo Valley, Wellington, New Zealand, in relation to food-plant availability. New Zealand Journal of Zoology 3, 399–419.
| Diet of the opossum Trichosurus vulpecula (Kerr) in the Orongorongo Valley, Wellington, New Zealand, in relation to food-plant availability.Crossref | GoogleScholarGoogle Scholar |
Fitzgerald, A. E., and Wardle, P. (1979). Food of the opossum Trichosurus vulpecula (Kerr) in the Waiho Valley, South Westland. New Zealand Journal of Zoology 6, 339–345.
| Food of the opossum Trichosurus vulpecula (Kerr) in the Waiho Valley, South Westland.Crossref | GoogleScholarGoogle Scholar |
Freeland, W. J., and Janzen, D. H. (1974). Strategies in herbivory by mammals: the role of plant secondary compounds. American Naturalist 108, 269–289.
| Strategies in herbivory by mammals: the role of plant secondary compounds.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2cXkvVynsrs%3D&md5=3ecc2a05082c997124f06c3112045dbbCAS |
Gill, R. M. A., and Morgan, G. (2010). The effects of varying deer density on natural regeneration in woodlands in lowland Britain. Forestry 83, 53–63.
| The effects of varying deer density on natural regeneration in woodlands in lowland Britain.Crossref | GoogleScholarGoogle Scholar |
Gormley, A. M., Holland, E. P., Pech, R. P., Thomson, C., and Reddiex, B. (2012). Impacts of an invasive herbivore on indigenous forests. Journal of Applied Ecology 49, 1296–1305.
| Impacts of an invasive herbivore on indigenous forests.Crossref | GoogleScholarGoogle Scholar |
Hone, J. (1994). ‘Analysis of Vertebrate Pest Control.’ (Cambridge University Press: New York.)
Kie, J. G. (1999). Optimal foraging and risk of predation: effects on behaviour and social structure in ungulates. Journal of Mammalogy 80, 1114–1129.
| Optimal foraging and risk of predation: effects on behaviour and social structure in ungulates.Crossref | GoogleScholarGoogle Scholar |
King, C. M. (2005). ‘The Handbook of New Zealand Mammals.’ 2nd edn. (Oxford University Press: Melbourne.)
Krebs, J. R. (1978). Optimal foraging: decision rules for predators. In ‘Behavioural Ecology: an Evolutionary Approach’. (Eds J. R. Krebs and N. B. Davies.) pp. 23–63. (Blackwell: Oxford, UK.)
Krebs, J. R. (1980). Optimal foraging, predation risk and territory defence. Ardea 68, 83–90.
Launchbaugh, K. L., Provenza, F. D., and Burritt, E. A. (1993). How herbivores track variable environments: reponse to variability of phytotoxins. Journal of Chemical Ecology 19, 1047–1056.
| How herbivores track variable environments: reponse to variability of phytotoxins.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXkvVyls7s%3D&md5=ac2cf5c3e7d1cbf9f7af4bc66e4f2d36CAS | 24249124PubMed |
MacArthur, R. H., and Pianka, E. R. (1966). On optimal use of a patchy environment. American Naturalist 100, 603–609.
| On optimal use of a patchy environment.Crossref | GoogleScholarGoogle Scholar |
Montague, T. L. (2000). ‘The Brushtail Possum. Biology, Impact and Management of an Introduced Marsupial.’ (Manaaki Whenua Press: Lincoln, New Zealand.)
Morgan, D., Nugent, G., and Warburton, B. (2006). Benefits and feasibility of local elimination of possum populations. Wildlife Research 33, 605–614.
| Benefits and feasibility of local elimination of possum populations.Crossref | GoogleScholarGoogle Scholar |
Murphy, E. C., and Bradfield, P. (1992). Changes in the diet of stoats following poisoning of rats in a New Zealand forest. New Zealand Journal of Ecology 16, 137–140.
Norbury, G., and Heyward, R. (1996). The response of ferrets to rabbit control. In ‘Ferrets as Vectors of Tuberculosis and Threats to Conservation’. pp. 30–33. The Royal Society of New Zealand Miscellaneous Series 36. Royal Society of New Zealand, Wellington.
Norton, D. (2000). Benefits of possum control for native vegetation. In ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial.’ (Ed. T. L. Montague.) pp. 232–240. (Manaaki Whenua Press: Lincoln, New Zealand.)
Nugent, G., Fraser, K. W., and Sweetapple, P. J. (1997). Comparison of red deer and possum diets and impacts in podocarp–hardwood forests, Waihaha catchment, Pureora Conservation Park. Science for Conservation 50. Department of Conservation, Wellington, New Zealand.
Nugent, G., Sweetapple, P. J., Coleman, J. D., and Suisted, P. A. (2000). Possum feeding patterns: Dietary tactics of a reluctant folivore. In ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial’. (Ed. T. L. Montague.) pp. 10–23. (Manaaki Whenua Press: Lincoln, New Zealand.)
Nugent, G., Fraser, W., and Sweetapple, P. (2001). Top down or bottom up? Comparing the impacts of introduced arboreal possums and ‘terrestrial’ ruminants on native forests in New Zealand. Biological Conservation 99, 65–79.
| Top down or bottom up? Comparing the impacts of introduced arboreal possums and ‘terrestrial’ ruminants on native forests in New Zealand.Crossref | GoogleScholarGoogle Scholar |
Nugent, G., Whitford, J., Innes, J., and Prime, K. (2002). Rapid recovery of kohekohe (Dysoxylum spectabile) following possum control. New Zealand Journal of Ecology 26, 73–79.
Nugent, G., Whitford, J., Sweetapple, P., Duncan, R., and Holland, P. (2010). Effect of one-hit control on the density of possums (Trichosurus vulpecula) and their impacts on native forest. Science for Conservation 304. Department of Conservation, Wellington, New Zealand.
Nugent, G., Warburton, B., Thompson, C., Sweetapple, P., and Ruscoe, W. (2011). Effect of prefeeding,sowing rate and sowing pattern on efficacy of aerial 1080 poisoning of small-mammal pests in New Zealand. Wildlife Research 38, 249–259.
| Effect of prefeeding,sowing rate and sowing pattern on efficacy of aerial 1080 poisoning of small-mammal pests in New Zealand.Crossref | GoogleScholarGoogle Scholar |
Orchan, Y., Chiron, F., Shwartz, A., and Kark, S. (2013). The complex interaction network among multiple invasive bird species in a cavity-nesting community. Biological Invasions 15, 429–445.
| The complex interaction network among multiple invasive bird species in a cavity-nesting community.Crossref | GoogleScholarGoogle Scholar |
Owen, H. J., and Norton, D. A. (1995). The diet of introduced brushtail possums Trichosurus vulpecula in a low-diversity New Zealand Nothofagus forest and possible implications for conservation management. Biological Conservation 71, 339–345.
| The diet of introduced brushtail possums Trichosurus vulpecula in a low-diversity New Zealand Nothofagus forest and possible implications for conservation management.Crossref | GoogleScholarGoogle Scholar |
Parkes, J., and Murphy, E. (2003). Management of introduced mammals in New Zealand. New Zealand Journal of Zoology 30, 335–359.
| Management of introduced mammals in New Zealand.Crossref | GoogleScholarGoogle Scholar |
Payton, I. (2000). Damage to native forests. In ‘The Brushtail Possum: Biology, Impact and Management of an Introduced Marsupial’. (Ed. T. L. Montague.) pp. 111–125. (Manaaki Whenua Press: Lincoln, New Zealand.)
Payton, I. J., Forester, L., Frampton, C. M., and Thomas, M. D. (1997). Response of selected tree species to culling of introduced Australian brushtail possums Trichosurus vulpecula at Waipoua Forest, Northland New Zealand. Biological Conservation 81, 247–255.
| Response of selected tree species to culling of introduced Australian brushtail possums Trichosurus vulpecula at Waipoua Forest, Northland New Zealand.Crossref | GoogleScholarGoogle Scholar |
Pech, R., Byrom, A., Anderson, D., Thomson, C., and Coleman, M. (2010). The effect of poisoned and notional vaccinated buffers on possum (Trichosurus vulpecula) movements: minimising the risk of bovine tuberculosis spread from forest to farmland. Wildlife Research 37, 283–292.
| The effect of poisoned and notional vaccinated buffers on possum (Trichosurus vulpecula) movements: minimising the risk of bovine tuberculosis spread from forest to farmland.Crossref | GoogleScholarGoogle Scholar |
R Development Core Team (2011). ‘R: a Language and Environment for Statistical Computing.’ (R Foundation for Statistical Computing: Vienna.) Available at http://www.R-project.org/ [verified March 2012].
Ramsey, D., Efford, M., Ball, S., and Nugent, G. (2005). The evaluation of indices of animal abundance using spatial simulation of animal trapping. Wildlife Research 32, 229–237.
| The evaluation of indices of animal abundance using spatial simulation of animal trapping.Crossref | GoogleScholarGoogle Scholar |
Ruscoe, W. A., Ramsay, D. S. L., Pech, R. P., Sweetapple, P. J., Yockney, I., Barron, M. C., Perry, M., Nugent, G., Carran, R., Warne, R., Brausch, C., and Duncan, R. P. (2011). Unexpected consequences of control; competitive vs. predator release in a four-species assemblage of invasive mammals. Ecology Letters 14, 1035–1042.
| Unexpected consequences of control; competitive vs. predator release in a four-species assemblage of invasive mammals.Crossref | GoogleScholarGoogle Scholar | 21806747PubMed |
Sessions, L. A., Rance, C., Grant, A., and Kelly, D. (2001). Possum (Trichosurus vulpecula) control benefits native beech mistletoes (Loranthaceae). New Zealand Journal of Ecology 25, 27–33.
Sinclair, A. R. E., and Byrom, A. E. (2006). Understanding ecosystem dynamics for conservation of biota. Journal of Animal Ecology 75, 64–79.
| Understanding ecosystem dynamics for conservation of biota.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28vnvVyrsA%3D%3D&md5=05dac2353a58046a6508fe5a6b879cfaCAS |
Sinclair, A. R. E., and Krebs, C. J. (2002). Complex numerical responses to top-down and bottom-up processes in vertebrate populations. Philosophical Transactions of the Royal Society of London. Series B. Biological Sciences 357, 1221–1231.
| Complex numerical responses to top-down and bottom-up processes in vertebrate populations.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD38njvVelsw%3D%3D&md5=7811fb46cf354686b90e610fd0a7d256CAS |
Smale, M. C., and Smale, P. N. (2003). Dynamics of upland conifer/broadleaved forest at Waihaha, central North Island, New Zealand. Journal of the Royal Society of New Zealand 33, 509–528.
| Dynamics of upland conifer/broadleaved forest at Waihaha, central North Island, New Zealand.Crossref | GoogleScholarGoogle Scholar |
Sweetapple, P. J. (2003). Possum (Trichosurus vulpecula) diet in a mast and non-mast seed year in a New Zealand Nothofagus forest. New Zealand Journal of Ecology 27, 157–167.
Sweetapple, P. J., and Nugent, G. (1998). Comparison of two techniques for assessing possum (Trichosurus vulpecula) diet from stomach contents. New Zealand Journal of Ecology 22, 181–188.
Sweetapple, P. J., and Nugent, G. (2004). Seedling ratios: a simple method for assessing ungulate impacts on forest understories. Wildlife Society Bulletin 32, 137–147.
| Seedling ratios: a simple method for assessing ungulate impacts on forest understories.Crossref | GoogleScholarGoogle Scholar |
Sweetapple, P. J., and Nugent, G. (2007). Ship rat demography and diet following possum control in a mixed podocarp–hardwood forest. New Zealand Journal of Ecology 31, 186–201.
Sweetapple, P. J., Nugent, G., Whitford, J., and Knightbridge, P. I. (2002). Mistletoe (Tupeia antarctica) recovery and decline following possum control in a New Zealand forest. New Zealand Journal of Ecology 26, 61–71.
Sweetapple, P. J., Fraser, K. W., and Knightbridge, P. I. (2004). Diet and impacts of brushtail possum populations across an invasion front in South Westland, New Zealand. New Zealand Journal of Ecology 28, 19–33.
Tanentzap, A. J., Burrows, L. E., Lee, W. G., Nugent, G., Maxwell, J. M., and Coomes, D. A. (2009). Landscape-level vegetation recovery from herbivory: progress after four decades of invasive red deer control. Journal of Applied Ecology 46, 1064–1072.
| Landscape-level vegetation recovery from herbivory: progress after four decades of invasive red deer control.Crossref | GoogleScholarGoogle Scholar |
Tilghman, N. G. (1989). Impacts of white-tailed deer on forest regeneration in northwestern Pennsylvania. The Journal of Wildlife Management 53, 524–532.
| Impacts of white-tailed deer on forest regeneration in northwestern Pennsylvania.Crossref | GoogleScholarGoogle Scholar |
Tremblay, J., Huot, J., and Potvin, F. (2006). Divergent nonlinear responses of the boreal forest field layer along an experimental gradient of deer densities. Oecologia 150, 78–88.
| Divergent nonlinear responses of the boreal forest field layer along an experimental gradient of deer densities.Crossref | GoogleScholarGoogle Scholar | 16896768PubMed |
Veblen, T. T., and Stewart, G. H. (1982). The effect of introduced wild animals on New Zealand forests. Annals of the Association of American Geographers 72, 372–397.
| The effect of introduced wild animals on New Zealand forests.Crossref | GoogleScholarGoogle Scholar |
Wallach, A. D., Johnson, C. N., Ritchie, E. G., and O’Neill, A. J. (2010). Predator control promotes invasive dominated ecological states. Ecology Letters 13, 1008–1018.
| 20545732PubMed |
Wardle, P. (1991). ‘Vegetation of New Zealand.’ (Cambridge University Press: Cambridge, UK.)
Wiggins, N. L., McArthur, C., and Davies, N. W. (2006). Diet switching in a generalist mammalian folivore: fundamental to maximising intake. Oecologia 147, 650–657.
| Diet switching in a generalist mammalian folivore: fundamental to maximising intake.Crossref | GoogleScholarGoogle Scholar | 16328546PubMed |
