Potential drivers of common brushtail possum (Trichosurus vulpecula) decline on a Murray River floodplain
H. Neilly A B * , T. McKenzie B , M. Ward C D , A. Chaber B and P. Cale A
+ Author Affiliations
- Author Affiliations
A Australian Landscape Trust, Calperum Station, PO Box 955, Renmark, SA 5341, Australia.
B School of Animal and Veterinary Science, The University of Adelaide, Roseworthy, Australia.
C School of Earth and Environmental Sciences, The University of Queensland, Brisbane, Australia.
D World Wild Fund Australia, Level 4B, 340 Adelaide Street, Brisbane, Qld 4000, Australia.
Australian Mammalogy 45(1) 62-70 https://doi.org/10.1071/AM22004
Submitted: 26 January 2022 Accepted: 28 May 2022 Published: 6 July 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the Australian Mammal Society.
Abstract
Australia’s terrestrial mammalian fauna have experienced severe declines since European settlement. On the Murray–Darling floodplain in south-eastern Australia, common brushtail possums (Trichosurus vulpecula, ‘possums’), have contracted to riparian zones. Although an important possum refuge, little is known about possum population dynamics here. We examined possum population dynamics and potential drivers across two decades on the Murray River floodplain at Calperum Station. We related possum density to satellite derived fractional cover, (a measure of the proportion of green, non-green and bare ground cover), and contextualised these findings using tree condition and grazing pressure datasets. Possum surveys were conducted between 1998 and 2019 in riparian and non-riparian habitats and density was modelled in relation to fractional cover values of green, non-green, and bare ground. Possum density fluctuated between 1998 and 2008 but in 2018 and 2019, possums were undetectable. Possum density was negatively associated with bare ground and positively associated with non-green. Overgrazing by kangaroos likely reduced vegetation cover and diversity and contributed to possum decline, via a reduction in possum food resources and increased exposure to predation. Inconsistent monitoring meant that the population decline was not detected until after it had occurred, and management interventions were not triggered, highlighting the dilemma of allocating scarce monitoring resources.
Keywords: arboreal marsupial, blackbox woodlands, Calperum Station, critical weight range, mammal decline, Murray–Darling Basin, Phalangeridae, riparian, river red gum woodlands.
References
Bannister, H. (2019). Release protocols and release environment: what influences reintroduction success for the brushtail possum? PhD thesis, The University of Adelaide, South Australia, Australia.Bannister, H., Brandle, R., and Moseby, K. (2018). Antipredator behaviour of a native marsupial is relaxed when mammalian predators are excluded. Wildlife Research 45, 726.
| Antipredator behaviour of a native marsupial is relaxed when mammalian predators are excluded.Crossref | GoogleScholarGoogle Scholar |
Barker, R. D. (1987). The diet of herbivores in the sheep rangelands. In ‘Kangaroos: Their Ecology and Management in the Sheep Rangelands of Australia’. (Eds G. Caughley, N. Shepard, J. Short) pp. 69–82. (Cambridge University Press: Cambridge.)
Barton, P. S., Manning, A. D., Gibb, H., Wood, J. T., Lindenmayer, D. B., and Cunningham, S. A. (2011). Experimental reduction of native vertebrate grazing and addition of logs benefit beetle diversity at multiple scales. Journal of Applied Ecology 48, 943–951.
| Experimental reduction of native vertebrate grazing and addition of logs benefit beetle diversity at multiple scales.Crossref | GoogleScholarGoogle Scholar |
Burbidge, A. A., and McKenzie, N. L. (1989). Patterns in the modern decline of western Australia’s vertebrate fauna: Causes and conservation implications. Biological Conservation 50, 143–198.
| Patterns in the modern decline of western Australia’s vertebrate fauna: Causes and conservation implications.Crossref | GoogleScholarGoogle Scholar |
Cale, P. (2020). ‘Evidence-based recovery plan for the Calperum Floodplain 2020-2025.’ (Australian Landscape Trust.)
Catelotti, K., Kingsford, R. T., Bino, G., and Bacon, P. (2015). Inundation requirements for persistence and recovery of river red gums (Eucalyptus camaldulensis) in semi-arid Australia. Biological Conservation 184, 346–356.
| Inundation requirements for persistence and recovery of river red gums (Eucalyptus camaldulensis) in semi-arid Australia.Crossref | GoogleScholarGoogle Scholar |
Dixon, K. M., Cary, G. J., Worboys, G. L., Banks, S. C., and Gibbons, P. (2019). Features associated with effective biodiversity monitoring and evaluation. Biological Conservation 238, 108221.
| Features associated with effective biodiversity monitoring and evaluation.Crossref | GoogleScholarGoogle Scholar |
Doherty, T. S., Dickman, C. R., Nimmo, D. G., and Ritchie, E. G. (2015). Multiple threats, or multiplying the threats? Interactions between invasive predators and other ecological disturbances. Biological Conservation 190, 60–68.
| Multiple threats, or multiplying the threats? Interactions between invasive predators and other ecological disturbances.Crossref | GoogleScholarGoogle Scholar |
Eldridge, D. J., Ding, J., and Travers, S. K. (2021). Low‐intensity kangaroo grazing has largely benign effects on soil health. Ecological Management & Restoration 22, 58–63.
| Low‐intensity kangaroo grazing has largely benign effects on soil health.Crossref | GoogleScholarGoogle Scholar |
Finlayson, G., Tschirner, K., McCann, J., and Appleby, M. (2021). Kangaroo management in the South Australian rangelands: Impacts and challenges for conservation management. Ecological Management & Restoration 22, 24–34.
| Kangaroo management in the South Australian rangelands: Impacts and challenges for conservation management.Crossref | GoogleScholarGoogle Scholar |
Fisher, A. G., Mills, C. H., Lyons, M., Cornwell, W. K., and Letnic, M. (2021). Remote sensing of trophic cascades: multi‐temporal landsat imagery reveals vegetation change driven by the removal of an apex predator. Landscape Ecology 36, 1341–1358.
| Remote sensing of trophic cascades: multi‐temporal landsat imagery reveals vegetation change driven by the removal of an apex predator.Crossref | GoogleScholarGoogle Scholar |
Flood, N. (2013). Seasonal composite Landsat TM/ETM+ images using the medoid (a multi-dimensional median). Remote Sensing 5, 6481–6500.
| Seasonal composite Landsat TM/ETM+ images using the medoid (a multi-dimensional median).Crossref | GoogleScholarGoogle Scholar |
Forward, L. R., and Robinson, A. C. (1996). ‘A biological survey of the South Olary Plains South Australia.’ (Biological Survey and Research, Natural Resources Group, Department of Environment and Natural Resources: South Australia.)
Foster, C. N., O’Loughlin, L. S., Sato, C. F., Westgate, M. J., Barton, P. S., Pierson, J. C., Balmer, J. M., Catt, G., Chapman, J., Detto, T., Hawcroft, A., Jones, G., Kavanagh, R. P., McKay, M., Marshall, D., Moseby, K. E., Perry, M., Robinson, D., Seddon, J. A., Tuft, K., and Lindenmayer, D. B. (2019). How practitioners integrate decision triggers with existing metrics in conservation monitoring. Journal of Environmental Management 230, 94–101.
| How practitioners integrate decision triggers with existing metrics in conservation monitoring.Crossref | GoogleScholarGoogle Scholar | 30273788PubMed |
Foulkes, J. (2001). The ecology and management of the common brushtail possum Trichosurus vulpecula in Central Australia. PhD thesis, University of Canberra Canberra, ACT, Australia.
Gellie, N. J., Breed, M. F., Mortimer, P. E., Harrison, R. D., Xu, J., and Lowe, A. J. (2018). Networked and embedded scientific experiments will improve restoration outcomes. Frontiers in Ecology and the Environment 16, 288–294.
| Networked and embedded scientific experiments will improve restoration outcomes.Crossref | GoogleScholarGoogle Scholar |
How, R. A., and Hillcox, S. J. (2000). Brushtail possum, Trichosurus vulpecula, populations in south-western Australia: demography, diet and conservation status. Wildlife Research 27, 81.
| Brushtail possum, Trichosurus vulpecula, populations in south-western Australia: demography, diet and conservation status.Crossref | GoogleScholarGoogle Scholar |
How, R. A., and Kerle, J. A. (1995). Common brushtail possum, Trichosurus vulpecula. In ‘The Mammals of Australia’. (Ed. R. Strahan.) pp. 273–275. (Reed Books: Chatswood, NSW.)
Howland, B., Stojanovic, D., Gordon, I. J., Manning, A. D., Fletcher, D., and Lindenmayer, D. B. (2014). Eaten out of house and home: Impacts of grazing on ground-dwelling reptiles in Australian grasslands and grassy woodlands. PLoS One 9, e105966.
| Eaten out of house and home: Impacts of grazing on ground-dwelling reptiles in Australian grasslands and grassy woodlands.Crossref | GoogleScholarGoogle Scholar | 25501680PubMed |
Howland, B. W. A., Stojanovic, D., Gordon, I. J., Radford, J., Manning, A. D., and Lindenmayer, D. B. (2016). Birds of a feather flock together: Using trait-groups to understand the effect of macropod grazing on birds in grassy habitats. Biological Conservation 194, 89–99.
| Birds of a feather flock together: Using trait-groups to understand the effect of macropod grazing on birds in grassy habitats.Crossref | GoogleScholarGoogle Scholar |
Kerle, J. A. (2001). ‘Possums: the brushtails, ringtails and greater glider’. (Ed T. J. Dawson) (UNSW Press: Sydney, Australia.)
Kerle, J. A., Foulkes, J., Kimber, R. G., and Papenfus, D. (1992). The decline of the Brushtail Possum, Trichosurus vulpecula (Kerr 1798), in arid Australia. Rangeland Journal 14, 107–127.
| The decline of the Brushtail Possum, Trichosurus vulpecula (Kerr 1798), in arid Australia.Crossref | GoogleScholarGoogle Scholar |
Kingsford, R. T. (2000). Ecological impacts of dams, water diversions and river management on floodplain wetlands in Australia. Austral Ecology 25, 109–127.
| Ecological impacts of dams, water diversions and river management on floodplain wetlands in Australia.Crossref | GoogleScholarGoogle Scholar |
Kingsford, R. T., Biggs, H. C., and Pollard, S. R. (2011). Strategic Adaptive Management in freshwater protected areas and their rivers. Biological Conservation 144, 1194–1203.
| Strategic Adaptive Management in freshwater protected areas and their rivers.Crossref | GoogleScholarGoogle Scholar |
Lawley, V., Lewis, M., Clarke, K., and Ostendorf, B. (2016). Site-based and remote sensing methods for monitoring indicators of vegetation condition: An Australian review. Ecological Indicators 60, 1273–1283.
| Site-based and remote sensing methods for monitoring indicators of vegetation condition: An Australian review.Crossref | GoogleScholarGoogle Scholar |
Lindenmayer, D. B., and Likens, G. E. (2009). Adaptive monitoring: a new paradigm for long-term research and monitoring. Trends in Ecology & Evolution 24, 482–486.
| Adaptive monitoring: a new paradigm for long-term research and monitoring.Crossref | GoogleScholarGoogle Scholar |
Lindenmayer, D. B., Piggott, M. P., and Wintle, B. A. (2013). Counting the books while the library burns: why conservation monitoring programs need a plan for action. Frontiers in Ecology and the Environment 11, 549–555.
| Counting the books while the library burns: why conservation monitoring programs need a plan for action.Crossref | GoogleScholarGoogle Scholar |
Lindenmayer, D., Woinarski, J., Legge, S., Southwell, D., Lavery, T., Robinson, N., Scheele, B., and Wintle, B. (2020). A checklist of attributes for effective monitoring of threatened species and threatened ecosystems. Journal of Environmental Management 262, 110312.
| A checklist of attributes for effective monitoring of threatened species and threatened ecosystems.Crossref | GoogleScholarGoogle Scholar | 32250795PubMed |
Manning, A. D., Cunningham, R. B., and Lindenmayer, D. B. (2013). Bringing forward the benefits of coarse woody debris in ecosystem recovery under different levels of grazing and vegetation density. Biological Conservation 157, 204–214.
| Bringing forward the benefits of coarse woody debris in ecosystem recovery under different levels of grazing and vegetation density.Crossref | GoogleScholarGoogle Scholar |
McAlpine, C., Catterall, C. P., Nally, R. M., Lindenmayer, D., Reid, J. L., Holl, K. D., Bennett, A. F., Runting, R. K., Wilson, K., Hobbs, R. J., Seabrook, L., Cunningham, S., Moilanen, A., Maron, M., Shoo, L., Lunt, I., Vesk, P., Rumpff, L., Martin, T. G., Thomson, J., and Possingham, H. (2016). Integrating plant- and animal-based perspectives for more effective restoration of biodiversity. Frontiers in Ecology and the Environment 14, 37–45.
| Integrating plant- and animal-based perspectives for more effective restoration of biodiversity.Crossref | GoogleScholarGoogle Scholar |
McKenzie, N. L., Burbidge, A. A., Baynes, A., Brereton, R. N., Dickman, C. R., Gordon, G., Gibson, L. A., Menkhorst, P. W., Robinson, A. C., Williams, M. R., and Woinarski, J. C. Z. (2007). Analysis of factors implicated in the recent decline of Australia’s mammal fauna. Journal of Biogeography 34, 597–611.
| Analysis of factors implicated in the recent decline of Australia’s mammal fauna.Crossref | GoogleScholarGoogle Scholar |
Mills, C. H., Waudby, H., Finlayson, G., Parker, D., Cameron, M., and Letnic, M. (2020). Grazing by over-abundant native herbivores jeopardizes conservation goals in semi-arid reserves. Global Ecology and Conservation 24, e01384.
| Grazing by over-abundant native herbivores jeopardizes conservation goals in semi-arid reserves.Crossref | GoogleScholarGoogle Scholar |
Moseby, K. E., Brandle, R., Hodgens, P., and Bannister, H. L. (2020). Can reintroductions to degraded habitat succeed? A test using the common brushtail possum. Austral Ecology 45, 675–690.
| Can reintroductions to degraded habitat succeed? A test using the common brushtail possum.Crossref | GoogleScholarGoogle Scholar |
Moxham, C., Duncan, M., and Moloney, P. (2018). Tree health and regeneration response of Black Box (Eucalyptus largiflorens) to recent flooding. Ecological Management & Restoration 19, 58–65.
| Tree health and regeneration response of Black Box (Eucalyptus largiflorens) to recent flooding.Crossref | GoogleScholarGoogle Scholar |
Nakagawa, S., and Schielzeth, H. (2013). A general and simple method for obtaining R2 from generalized linear mixed-effects models. Methods in Ecology and Evolution 4, 133–142.
| A general and simple method for obtaining R2 from generalized linear mixed-effects models.Crossref | GoogleScholarGoogle Scholar |
Neilly, H., and Cale, P. (2020). ‘Branching’ with complex coarse woody debris reduces herbivory on recovering erosion scalds. Ecological Management & Restoration 21, 143–146.
| ‘Branching’ with complex coarse woody debris reduces herbivory on recovering erosion scalds.Crossref | GoogleScholarGoogle Scholar |
Neilly, H., and Schwarzkopf, L. (2017). The response of an arboreal mammal to livestock grazing is habitat dependant. Scientific Reports 7, 17382.
| The response of an arboreal mammal to livestock grazing is habitat dependant.Crossref | GoogleScholarGoogle Scholar | 29234116PubMed |
Neilly, H., Ward, M., and Cale, P. (2021). Converting rangelands to reserves: Small mammal and reptile responses 24 years after domestic livestock grazing removal. Austral Ecology 46, 1112–1124.
| Converting rangelands to reserves: Small mammal and reptile responses 24 years after domestic livestock grazing removal.Crossref | GoogleScholarGoogle Scholar |
Nisbet, E. (2007). Cinderella science. Nature 450, 789–790.
| Cinderella science.Crossref | GoogleScholarGoogle Scholar | 18063983PubMed |
Pavey, C. R., Addison, J., Brandle, R., Dickman, C. R., McDonald, P. J., Moseby, K. E., and Young, L. I. (2017). The role of refuges in the persistence of Australian dryland mammals: Mammal refuges in drylands. Biological Reviews 92, 647–664.
| The role of refuges in the persistence of Australian dryland mammals: Mammal refuges in drylands.Crossref | GoogleScholarGoogle Scholar | 26685752PubMed |
Pettorelli, N., Laurance, W. F., O’Brien, T. G., Wegmann, M., Nagendra, H., and Turner, W. (2014). Satellite remote sensing for applied ecologists: opportunities and challenges. Journal of Applied Ecology 51, 839–848.
| Satellite remote sensing for applied ecologists: opportunities and challenges.Crossref | GoogleScholarGoogle Scholar |
Pittock, J., and Finlayson, C. M. (2011). Australia’s Murray–Darling Basin: freshwater ecosystem conservation options in an era of climate change. Marine and Freshwater Research 62, 232.
| Australia’s Murray–Darling Basin: freshwater ecosystem conservation options in an era of climate change.Crossref | GoogleScholarGoogle Scholar |
Ramsey, D., Efford, M., Cowan, P., and Coleman, J. (2002). Factors influencing annual variation in breeding by common brushtail possums (Trichosurus vulpecula) in New Zealand. Wildlife Research 29, 39.
| Factors influencing annual variation in breeding by common brushtail possums (Trichosurus vulpecula) in New Zealand.Crossref | GoogleScholarGoogle Scholar |
R Core Team (2020). ‘R: A language and environment for statistical computing.’ (R Foundation for Statistical Computing: Vienna, Austria.) Available at https://www.R-project.org
Rees, J. D., Kingsford, R. T., and Letnic, M. (2017). In the absence of an apex predator, irruptive herbivores suppress grass seed production: Implications for small granivores. Biological Conservation 213, 13–18.
| In the absence of an apex predator, irruptive herbivores suppress grass seed production: Implications for small granivores.Crossref | GoogleScholarGoogle Scholar |
Reynolds, J. H., Knutson, M. G., Newman, K. B., Silverman, E. D., and Thompson, W. L. (2016). A road map for designing and implementing a biological monitoring program. Environmental Monitoring and Assessment 188, 399.
| A road map for designing and implementing a biological monitoring program.Crossref | GoogleScholarGoogle Scholar | 27277094PubMed |
Robinson, N. M., Dexter, N., Brewster, R., Maple, D., MacGregor, C., Rose, K., Hall, J., and Lindenmayer, D. B. (2020). Be nimble with threat mitigation: lessons learned from the reintroduction of an endangered species. Restoration Ecology 28, 29–38.
| Be nimble with threat mitigation: lessons learned from the reintroduction of an endangered species.Crossref | GoogleScholarGoogle Scholar |
Scarth, P., Roder, A., and Schmidt, M. (2010). Tracking grazing pressure and climate interaction - the role of landsat fractional cover in time series analysis. In 15th Australasian Remote Sensing and Photogrammetry Conference.
Scheele, B. C., Legge, S., Blanchard, W., Garnett, S., Geyle, H., Gillespie, G., Harrison, P., Lindenmayer, D., Lintermans, M., Robinson, N., and Woinarski, J. (2019). Continental-scale assessment reveals inadequate monitoring for threatened vertebrates in a megadiverse country. Biological Conservation 235, 273–278.
| Continental-scale assessment reveals inadequate monitoring for threatened vertebrates in a megadiverse country.Crossref | GoogleScholarGoogle Scholar |
Souter, N. J., Watts, R. A., White, M. G., George, A. K., and McNicol, K. J. (2010). A conceptual model of tree behaviour improves the visual assessment of tree condition. Ecological Indicators 10, 1064–1067.
| A conceptual model of tree behaviour improves the visual assessment of tree condition.Crossref | GoogleScholarGoogle Scholar |
Sparrow, B. D., Edwards, W., Munroe, S. E. M., Wardle, G. M., Guerin, G. R., Bastin, J.-F., Morris, B., Christensen, R., Phinn, S., and Lowe, A. J. (2020). Effective ecosystem monitoring requires a multi‐scaled approach. Biological Reviews 95, 1706–1719.
| Effective ecosystem monitoring requires a multi‐scaled approach.Crossref | GoogleScholarGoogle Scholar | 32648358PubMed |
Stobo-Wilson, A. M., Murphy, B. P., Cremona, T., and Carthew, S. M. (2019). Contrasting patterns of decline in two arboreal marsupials from Northern Australia. Biodiversity and Conservation 28, 2951–2965.
| Contrasting patterns of decline in two arboreal marsupials from Northern Australia.Crossref | GoogleScholarGoogle Scholar |
Tindall, D., Trevithick, R., Scarth, P., Collett, L., Goodwin, N., Denham, R., and Flood, N. (2014). Ground cover and fire in the grazing lands:RP64G Synthesis Report. Department of Science, Information Technology, Innovation and the Arts, Brisbane.
Woinarski, J. C. Z., Burbidge, A. A., and Harrison, P. L. (2015). Ongoing unraveling of a continental fauna: Decline and extinction of Australian mammals since European settlement. Proceedings of the National Academy of Sciences 112, 4531–4540.
| Ongoing unraveling of a continental fauna: Decline and extinction of Australian mammals since European settlement.Crossref | GoogleScholarGoogle Scholar |
Woinarski, J. C. Z., Braby, M. F., Burbidge, A. A., Coates, D., Garnett, S. T., Fensham, R. J., Legge, S. M., McKenzie, N. L., Silcock, J. L., and Murphy, B. P. (2019). Reading the black book: The number, timing, distribution and causes of listed extinctions in Australia. Biological Conservation 239, 108261.
| Reading the black book: The number, timing, distribution and causes of listed extinctions in Australia.Crossref | GoogleScholarGoogle Scholar |
